Georgia Tech Ramblin Rocketeers Flight Readiness Review

Transcription

1 eorgia Tech Flight Readiness Review

2 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW PAE INTENTIONALLY LEFT BLANK eorgia Institute of Technology 2 of 187

3 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table of Contents Table of Contents... 3 Table of Figures... 8 Table of Tables Introduction School Information and NAR Section Contacts Work Breakdown Structure Launch Vehicle Summary Overview Changes since CDR Payload Summary Overview Changes Since CDR Payload Changes Since CDR Avionics Changes Since CDR Project L.S.I.M. Overview Mission Statement Requirements Flow Down Mission Objectives and Mission Success Criteria System Requirements Verification Matrix (RVM) Mission Profile Launch Vehicle Overview Mission Criteria System Design Overview Recovery System Altimeters Arming Switches Parachute Dimensions Drift Profile Analysis Kinetic Energy of Launch Vehicle Ejection Charges Testing Structure Construction Payload Integration eorgia Institute of Technology 3 of 187

4 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Avionics Integration Section Integration Launch Vehicle Performance Analysis Altitude Predictions and Motor Selection Stability Testing Intimidator 5 Kit Mass Breakdown Interfaces and Integration Interface with the round Interface with the round Launch System Launch Vehicle Operations Launch Checklist Flight Experiment Introduction to the Experiment and Payload Concept Features & Definition Accomplishments Since CDR Important Changes Test Launch Lessons Learned Summary of Science Team Payload Report of Failures and Occurrences Integration Sensor detachment Openlog File Writing Results and Future Mitigation Integration Results Sensor data OpenLog Risk Mitigation Science Background Important Highlights Experiment Requirements and Objectives Success Criteria Requirements Hypothesis and Premise Experimental Method and Relevance of Data Testing plan eorgia Institute of Technology 4 of 187

5 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Overview MR Fluid Creation and Validation of Theory MR Fluid Shear Stress Characterization: Two Plate Test Working round Model Sensors Design review Viscosity Test Rig round Test MR fluid production and manipulation Hardware and build progress Sensing Solenoids Microcontroller Payload Relevance and Science Merit REFP REFP-Specific Design Work Containment Box Computer Weights Equipment Layout for Take-off, in Flight, and Landing Flight Experiment Integration Flight Avionics Avionics Overview Avionics Success Criteria SIDES Design Approach SIDESboard SIDES Electrical Harness Master IMU Science Experiment Computer Telemetry De-scope Options Power Budget EM Interference Transmission Frequencies and Protocols Software Maturity De-scope Option: Flight Computer Definition Avionics Testing and Reliability Assurance round Station Purpose Function eorgia Institute of Technology 5 of 187

6 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Design Considerations Choice of Antenna Choice of Camera Motor Sizing Software Maturity Effects of Excess RF Radiation on the Recovery Avionics Avionics Mechanical Integration eneral Safety Vehicle Safety and Environment Overview Mission Assurance Payload Safety Personnel and Environmental Hazards Project Budget Funding Overview Current Sponsors Actual Project Cost FRR Budget Summary System-Level Budget Summary Flight Hardware Expenditures Flight Hardware Expenditure Overview Flight Hardware Cost Breakdown Project Schedule Schedule Overview Critical Path Chart: CDR to PLAR Schedule Risk High Risk Items Low-to-Moderate Risk Tasks Educational Engagement Plan and Status Overview Atlanta Makers Faire FIRST Lego League and Tech Challenge References Appendix I: antt Chart Appendix II: Launch Checklist Appendix III: Science Overview Appendix IV: round Test Plan eorgia Institute of Technology 6 of 187

7 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix V: Science MFOs and Drawings Appendix VI: Altimeter Wiring Harness Schematic eorgia Institute of Technology 7 of 187

8 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table of Figures Figure project work breakdown structure Figure 2. Flow down of requirements Figure 3. Project L.S.I.M. mission profile Figure 4: Internal Layout of the Launch Vehicle Figure 5: Drogue Parachute Assembly Figure 6: Main Parachute Assembly Figure 7: Electronic Altimeter Schematic Figure 8: Featherweight Screw Switches Figure 9: Payload Integration Structure Figure 10: Avionics Integration Structure Figure 11: L1390 Altitude and Thrust vs. Time Figure 12: Launch Vehicle Stability vs. Time Figure 13: 45% Scale Test Rocket and Flight Figure 14: Intimidator 5 Kit Landing Mass Breakdown Figure 15: Correcting for Piezo drift Figure 16: FFT of corrected data showing peak around 26 Hz Figure 17: LSIM testing logic, illustrating a simple relationship of information between the test sequences and emphasizing that they flow down from the pursuit of the LSIM hypothesis Figure 18: Preliminary static testing of MR fluid mixtures in magnetic fields Figure 19: Shear stress of a fluid using the two-plate test (Source: Wikipedia) Figure 20: Piezo-electric sensor used for detecting anchor force oscillations Figure 21: Piezo-electric sensor circuit. The sensor is modeled as a variable-voltage source at 300 Hz. While 300 Hz is a theoretical maximum for the reading speed of the microcontroller, data was logged at a rate between Hz Figure 22: Top and bottom view of sensor prototype circuit. Leads soldered to the piezo-electric sensors are attached to the blue terminals, while pins go to the microcontroller for data logging and analog reading. This prototype supports two sensors and is approximately 3 inches by 5 inches. Final boards may be much smaller Figure 23: data showing sensor drift and a method of correction by distributing the data around the overall mean Figure 24: frequency spectrum for the entire dataset Figure 25: 4x4 solenoid driver. Two drivers can be linked together per microcontroller to control 32 solenoids directly. Approximately 3 inches by 2 inches Figure 26: Arduino Mega microcontroller with major dimensions Figure 27: Ideas for the containment box, illustrating some support elements and a possible electrical conduit Figure 28: bottom mounting bracket for the USLI sounding rocket. A larger version is intended to be used in the containment box. This piece attaches to the box - a second part attaches to the canister and snaps into the bracket Figure 29: Current weight budget with totals, and broken out by known subassemblies eorgia Institute of Technology 8 of 187

9 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 30: Summary of the weight budget to report subassembly totals Figure 31: Equipment layout for containment box, 6 canisters, laptop and crew for all stages of flight Figure 32: Payload Assembly Figure 33: Payload Base with 150N of loading Figure 34: Factor of Safety vs. Total Load from SolidWorks SimulationXpress and generated trend line equation Figure 35: SIDES system layout Figure 36: SIDESboard bottom side view Figure 37: SIDESboard top side view Figure 38: Xbee transceiver unit Figure 39: Antenna performance as a function of range Figure 40: eneralization of flight computer software Figure 41: Diagram of a helical antenna Figure 42: Typical radiation pattern for a helical antenna Figure 43: Canon Powershot SX Figure 44: High-Level Software Process Figure 45: Updating Rocket State Figure 46: Updating Servo Position Figure 47: Updating Camera Zoom Figure 48:Transmit Rocket Location Figure 49. System expenditure summary at CDR Figure 50. Sub-system Testing/Development Breakdown Figure 51. Sub-System Flight Hardware Breakdown Figure 52. Flight Systems flight hardware breakout Figure 6. Critical Path Chart from CDR to PLAR Figure 20. Participation at the Atlanta Makers' Faire Figure 21: Previous FIRST Lego League outreach event Figure 56: FLL Regional Event at Wheel High School Figure 57: FLL Regional Straw Rocket Activity Figure 58: Plot of B field magnitude in MR fluid versus magnitude of vector μ0h, for iron volume concentrations of 10, 20, and 30 percent Figure 59: Shear stress of ideal Bingham plastic (and MR fluid model) versus shear rate dvdn, compared to ideal Newtonian liquid Figure 60: Microgravity time as a function of launch angle from horizon Figure 61: Slosh regimes and similarity parameters Figure 62. Schematic and free-body diagram of slosh dynamic model Figure 63. Base Plate Figure 64. Second and Top Plate Figure 65. Side view of main structure Figure 66. Trimetric view of main structure Figure 67. Top view of structure with 90 Degree L Brackets eorgia Institute of Technology 9 of 187

10 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 68. Side view of 90 Degree Brackets Figure 69. Test Structure with Base Plates Table of Tables Table 1. Mission Objectives and Mission Success Criteria for the L.S.I.M. mission Table 2. Launch Vehicle RVM Table 3. Flight Systems RVM Table 4. Flight Avionics RVM Table 5: Mission Success Criteria Table 6: Launch Vehicle System Requirements Table 7: Launch Vehicles Properties Table 8: Recovery System Properties Table 9: Drift Estimates Table 10: Recovery Characteristics Table 11: Kinetic Energy at Drogue Parachute Deployment Table 12 : Kinetic Energy at Main Parachute Deployment Table 13: Black Powder Properties Table 14: Black Powder Masses Table 15: Success Criteria Table 16: Failure Modes Table 17: Altitude as a Function of Motor Selection (Constant Dry Mass) Table 18: Overall Weight Breakdown Table 19: Intimidator 5 Kit Landing Masses Table 20: Methods currently available for damping slosh Table 21: Elements of the theoretical modeling for the LSIM payload Table 22: LSIM success criteria from the Requirements Verification Matrix Table 23: LSIM Requirements Table 24: Scientific method fulfillment for LSIM Table 25: Test sequences and descriptions, included options de-scoped since PDR Table 26: List of MR fluid ingredients Table 27: Payload Assembly Dimensions Table 28: Data from SolidWorks SimulationXpress, highlighting the data from assumptions. 102 Table 29: Avionics requirements Table 30: Avionics Success Criteria Table 31. SIDES Power Budget Table 32: Major Flight Computer Components Table 33: round station requirements Table 34: Risk Identification and Mitigation Steps Table 35: Risk Assessment Matrix with Risk Class Table 36. Launch vehicle failure modes eorgia Institute of Technology 10 of 187

11 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 37. Payload hazards and mitigation Table 38. Payload safety failure modes Table 39: Environmental Hazards, Risks, and Mitigation Table 40. Summary of sponsors for the Ramblin. Rocketeers Table 41. List of current sponsors of the Ramblin' Rocketeers Table 42. FRR Project Budget Summary Table 43. Design milestones set by the USLI Program Office Table 44. Identification and Mitigations for High-Risk Tasks Table 45. Low to Moderate Risk items and mitigiations Table 46: Microgravity times for fall heights Table 47: Similarity parameters for simplified flight profile of the launch vehicle eorgia Institute of Technology 11 of 187

12 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 1. Introduction 1.1. School Information and NAR Section Contacts Team Summary School Info & Project Title School Name Team Name Project Title Launch Vehicle Name Payload Option eorgia Institute of Technology Liquid Stabilization in Microgravity (LSIM) Vespula Mk II 1,2 0F1 Project Lead / Team Richard Team Information Official Safety Officer Team Advisors Tony, Joseph Dr. Eric Feron Dr. Marilyn Wolf NAR Section Primary: Southern Area Rocketry (SoAR) #571 NAR Information NAR Contacts Secondary: A Tech Ramblin Launch vehicle Club #701 Primary: Matthew Vildzius Secondary: Jorge Blanco 1 The LSIM payload is applicable to both the Option 1 and Option 2 payload options listed in the USLI Handbook. On its own, the LSIM payload is intended to be an engineering payload demonstrating a novel technology; additionally, the LSIM payload can be scaled up and will be shown to meet the requirements to compete for the Option 2 payload option. eorgia Institute of Technology 12 of 187

13 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 1.2. Work Breakdown Structure In order to effectively coordinate design efforts, the project is broken down along technical discipline lines that emulate typical programs in the Aerospace industry. Each sub-team has a general manager supported by several technical leads and subordinate members. Team memberships were selected based on the individuals areas of expertise as well as personal interest. Figure 1 shows the work breakdown structure. Figure project work breakdown structure. eorgia Institute of Technology 13 of 187

14 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 1.3. Launch Vehicle Summary Overview The launch vehicle has a gross-lift off weight of approximately 45 pounds and features a 75 mm L1350 solid motor. The launch vehicle is an Intimidator 5 kit with a custom payload integration structure. The recovery system utilizes a 30 drogue parachute slowing the launch vehicle down to ft/s and a 120 main parachute to slow the launch vehicle down to ft/s Changes since CDR The following changes have been made since the Preliminary Design Review: Due to several launch failures the custom Vespula Mk II vehicle design has been descoped to the Intimidator 5 kit Payload Summary Overview The will design, build, test, and fly a system for damping liquid slosh through the use of magnetorheological fluid. This fluid will be actuated with solenoids and driven to a pre-defined state in the Liquid Stabilization in Microgravity (LSIM) experiment. Further, Flight Systems will implement a network of SIDESboards for distributed sensor networks, empowering LSIM, and collecting valuable engineering data. A substantial ground station for observation and telemetry is planned to support the flight of the launch vehicle. Additionally, the will pursue the NASA payload options 1 and 2 in the design, construction, testing, and flight of a primary science experiment and Reduced ravity Education Flight Program. This payload will test the feasibility and practicality of systems to manipulate magnetorheological (MR) fluids in microgravity for the purpose of demonstrating possible methods for reducing propellant slosh in low-gravity environments. eorgia Institute of Technology 14 of 187

15 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Changes Since CDR Payload Changes Since CDR All use of cameras for the science payload has been de-scoped Avionics Changes Since CDR Temperature and Strain auge nodes no longer necessary with switch from Vespulla MkII to Intimidator kit MasterIMU now uses a SIDESboard instead of a Maple, extra computing power not necessary because only two nodes use the SIDES network Master Clock node has been descoped, since there are only two nodes to synchronize RS485 Hardware will use simplified control software reflecting the simplifications to the SIDES network Infrared will no longer be used as a primary means of measuring slosh in the experiment for the launch vehicle. A camera independent of the avionics apparatus may be used however the primary sensor is seen to be a vibration sensor placed into the base bolt and integrated into a SIDES node. The precise details of ground testing have been reviewed in depth and many changes as to the specifics have been made as testing platforms have been developed. These should result in high quality ground testing data. This data will be used to complete the final link in an expanded theory describing MR fluid. While operating under several assumptions and simplifications, this expanded theory should aid greatly in the development of control software for the flight experiment. eorgia Institute of Technology 15 of 187

16 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 2. Project L.S.I.M. Overview 2.1. Mission Statement The mission of the Mile High Yellow Jackets is: To maintain a sustainable team dedicated to the gaining of knowledge through the designing, building, and launching of reusable launch vehicles with innovative payloads in accordance with the NASA University Student Launch Initiative uidelines Requirements Flow Down The requirements flow down is illustrated in Figure 2. As illustrated by the requirements flow down, the Mission Success Criteria flow down from the Mission Objectives of Project A.P.E.S. All system and sub-system level requirements flow down from the either of the Mission Objectives, Mission Success Criteria, or the USLI Handbook. eorgia Institute of Technology 16 of 187

17 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 2.3. Mission Objectives and Mission Success Criteria Table 1. Mission Objectives and Mission Success Criteria for the L.S.I.M. mission MO Mission Objective MO-1 An altitude of 5,280 ft above the ground is achieved. MO-2 Create an environment in which to test microgravity payloads. MO-3 Reduction in the sloshing motion of a propellant simulatn in microgravity with a magnetic fluid. MO-4 Successful recovery of the launch vehicle resulting in no damage to the launch vehicle. MSC Mission Success Criteria Source Verification Method MSC-1 Minimum Mission Succes: Achieve an altitude of Testing MO-1 5,280 ft., with a tolerance of +320 ft./-640 ft. MSC-2 Minimum Mission Succes: Achieve a microgravitiy Testing MO-2 environment of ± 0.1 MSC-3 Minimum Mission Success:Sucessfully record video Testing of flight experiment during microgravity and start/stop the experiment without mechanical and electrical MO-3 failures. MSC-4 Full Mission Succes: Successful matching of the Testing damping ratio for ringed baffles in the wave amplitudes MO-3 experienced during flight to within ±30%. MSC-5 Minimum Mission Success: The Launch Vehicle is MO-4,USLI Testing recovered with no damage to the structure of the launch vehicle. Handbook 1.4 MSC-5.1 Full Mission Succes:The Launch Vehicle is recovered with no damage to the skin of the launch vehicle. MSC-7, MO-4 Testing 2.1. System Requirements Verification Matrix (RVM) Table 2, Table 3, and Table 4 list the requirements verification matrix for each subsystem. eorgia Institute of Technology 17 of 187

18 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 2. Launch Vehicle RVM Requirement No. Requirement Source Verification Method Design Feature Status LV-1 The Launch Vehicle shall carry a scientific or engineering payload. USLI Handbook 1.1, MO-2 Inspection imps standardized payload interface In Progress The maximum LV-1.1 payload weight including any supporting avionics shall not exceed 15 LV-1 Inspection Maximum Parachute Sizing In Progress lbs. The Launch Vehicle Three (3) shall have a sections: LV-1.2 maximum of four USLI Handbook 1.5 Inspection nosecone, In Progress (4) independent or payload, and tethered sections booster LV-2 The Launch Vehicle shall carry the payload to an altitude of 5,280 ft. above the ground. USLI Handbook 1.1, MO-1 Testing Modified tube fins for straight flight, motor sizing In Progress eorgia Institute of Technology 18 of 187

19 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. LV-2.1 LV-2.2 LV-2.3 LV-2.4 Requirement The Launch Vehicle shall use a commercially available solid motor using ammonium perchlorate composite propellant (APCP). The total impulse provided by the Launch Vehicle shall not exceed 5,120 N-s. The Launch Vehicle shall remain subsonic throughout the entire flight. The Launch Vehicle shall carry one commercially available barometric altimeter for recording of the official altitude Source Verification Design Method Feature Status Use of a USLI Handbook commercially Inspection 1.11 available In Progress solid motor A motor with a maximum USLI Handbook Inspection motor class of 1.12 "L" shall be In Progress used USLI Handbook 1.3 Analysis Motor Sizing In Progress Commercially USLI Handbook 1.2 Inspection available In Progress altimeter eorgia Institute of Technology 19 of 187

20 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The amount of LV-2.5 ballast, in the vehicle's final configuration that will be flown in Huntsville, shall be no more than 10% of the unballasted USLI Handbook 1.14 Inspection Proper motor selection for gross lift-off weight of the launch vehicle. In Progress vehicle mass. The Launch Vehicle LV-2.5 shall have aerodynamic stability margin of 1.5 to 3 cailbers prior to leaving the LV-2 Analysis Modified tube-fins for aerodynamic stabilization. In Progress launch rail. Parachute The Launch Vehicle Sizing and LV-3 shall be safely recovered and be MSC-7.1 Testing real time round In Progress reusable. Station tracking The Launch Vehicle round LV-3.1 shall contain redundant USLI Handbook 2.5 Inspection testing of altimeter In Progress altimeters. ejection. eorgia Institute of Technology 20 of 187

21 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The recovery LV-3.2 system shall be designed to be LV-3 Inspection Arming Switches In Progress armed on the pad. The recovery LV-3.3 The recovery system electronics shall be completely independent of the payload electronics. USLI Handbook 2.4 Inspection system electronics shall be entirely independent of from all In Progress other systems. Each altimeter shall be armed by a Recovery dedicated arming system design switch which is shall accessible from the incorporate LV-3.4 exterior of the USLI Handbook 2.6 Inspection one (1) In Progress vehicle airframe independent when the vehicle is arming switch in the launch for each configuration on the altimeter launch pad. eorgia Institute of Technology 21 of 187

22 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status Recovery system design shall Each altimeter shall incorporate LV-3.5 have a dedicated USLI Handbook 2.7 Inspection independent In Progress power supply. power supplies for each altimeter. The arming Each arming switch switches will shall be capable of be designed to LV-3.6 being locked in the USLI Handbook 2.8 Testing use a key to In Progress "ON" position for change the launch. state of the switch. Arming LV-3.7 Each arming switch shall be a maximum of six (6) feet above the base of the Launch Vehicle. USLI Handbook 2.9 Inspection switches shall be located near the booster section of the launch In Progress vehicle The Launch Vehicle Utilization of LV-3.8 shall utilize a dual deployment USLI Handbook 2.1 Inspection a drogue and main In Progress recovery system. parachute eorgia Institute of Technology 22 of 187

23 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status Removable shear Plastic shear pins shall be used pins will be LV-3.9 for both the main and drogue USLI Handbook 2.10 Inspection installed in the recovery In Progress parachute compartments compartments. LV-3.10 All sections shall be designed to recover within 2,500 ft. of the launch pad assuming 15 MPH winds. USLI Handbook 2.3 Analysis Parachute sizing will incorporate descending velocities and drift restrictions. In Progress Properly sized LV-3.11 Each section of the Launch Vehicle shall have a maximum landing kinetic energy of 75 ft-lb f. USLI Handbook 2.2 Analysis main parachute to ensure landing kinetic energies below 75 ft.- In Progress lb f eorgia Institute of Technology 23 of 187

24 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status Proper shielding The recovery shall be system electronics incorporated LV-3.12 shall be shielded from all onboard LV-3 Testing into the design to In Progress transmitting protect the devices. electronics from payload interference. LV-4 The Launch Vehicle shall be launched utilizing standardized launch equipment LV-3 Inspection Use of standard 1515 rail buttons and 8 foot launch pad rail. In Progress The Launch Vehicle shall be capable of being launched by a standard 12 volt direct current (DC) Use of LV-4.1 firing system and USLI Handbook 1.9 Testing standard In Progress shall require no igniters. external circuitry or special ground support equipment to initial launch. eorgia Institute of Technology 24 of 187

25 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The Launch Vehicle LV-4.2 shall not require any external circuitry or special ground support equipment to initiate the launch other than what is provided by the USLI Handbook 1.10 Testing Use of standard igniters, 1515 rail buttons, and 8 foot launch rail. In Progress range. The Launch Vehicle Follow LV-4.4 shall have a pad stay time on one (1) USLI Handbook 1.7 Testing manufacturers recommendati In Progress hour. ons for power LV-4.5 The Launch Vehicle shall be capable of being prepared for flight at the launch site within two (2) hours from the time the waiver opens. USLI Handbook 1.6 Testing Easy assembly of the rocket structure and easy integration of the payload and avionics. In Progress The Launch Vehicle shall be compatible with either an 8 foot Utilization of LV-4.6 long, 1 in. rail (1010), or an 8 feet USLI Handbook 1.8 Testing 1515 rail and rail interfaces In Progress foot long, 1.5 in. rail for launch (1515), provided by the range. eorgia Institute of Technology 25 of 187

26 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 3. Flight Systems RVM Requirement Requirement Definition Source Verification Design Status Verification Number Method Feature Source Document FS-1 The flight systems team shall design and build the LSIM Payload MO-3 Inspection LSIM payload In Progress MO-3 FS-2 The LSIM payload shall be designed to fly on a SLP rocket USLI Handbook Inspection LSIM payload In Progress USLI Handbook FS-4 The Flight Systems Team shall produce a working system for manipulating MR fluid MSC-3 Testing Solenoids and Control Algorithms In Progress MSC-3 in LSIM. FS-5 The Flight Systems Team shall ensure that all avionics are properly shielded from the LSIM payload. MSC-3 Testing Faraday cages and webbing tied to ground on the harness Not Started MSC-3 FS-6 The Flight Systems Team shall design all LSIM components and avionics such that they may be easily integrated with the Modular MSC-3 Inspection Mounting system Complete MSC-3 Payload System of the payload bay in the rocket. eorgia Institute of Technology 26 of 187

27 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Definition Source Verification Design Status Verification Number Method Feature Source Document FS-7 The Flight Systems Team shall conform to all weight, power, and dimensional MSC-3 Analysis TBD In Progress MSC-3 requirements as per the rocket design. FS-7.1 The Experiment and Avionics, with mechanical supports, shall weight no more LV-1.1 Inspection TBD In Progress LV-1.1 than 15 lbf. FS-8 The flight computer shall execute all tasks necessary to the operation of the LSIM MSC-3 Inspection Maple SIDES node In Progress MSC-3 payload and avionics. FS-9 The LSIM payload shall have a dedicated power supply. MSC-3 Inspection SIDES node In Progress MSC-3 FS-10 The Flight Systems Team shall ensure redundancy and reliability of all internal MSC-3 Inspection SIDES network In Progress MSC-3 electrical hardware. eorgia Institute of Technology 27 of 187

28 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Definition Source Verification Design Status Verification Number Method Feature Source Document FS-11 The Flight Systems Team shall provide for payload operation with up to 1 hour of wait on the launch pad and 2 hours of wait during USLI Handbook 1.6 Inspection TBD In Progress USLI Handbook 1.6 preparation of the Rocket. FS-12 The Flight Systems Team shall provide for electrical operations to begin at the beginning MSC-3 Inspection TBD In Progress MSC-3 of the flight trajectory. FS-13 The Flight Systems Team shall ensure that the LSIM payload is shut down safely during MSC-3 Inspection TBD In Progress MSC-3 the deployment phase of the flight trajectory. FS-14 Data from the LSIM payload shall be collected, analyzed, and reported by the team using the scientific USLI Handbook 3.2 Inspection Data logging in SIDES network In Progress USLI Handbook 3.2 method. eorgia Institute of Technology 28 of 187

29 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Definition Source Verification Design Status Verification Number Method Feature Source Document FS-15 The LSIM payload will be designed to be recoverable and be able to launch again on the same day without any USLI Handbook 3.5 Inspection Appropriate mounting to the payload interface. In Progress USLI Handbook 3.5 repairs or modifications. Table 4. Flight Avionics RVM Requirement No. FA-1 FA-2 FA-3 Requirement All Flight Avionics shall have sufficient power sources to survive 1-hour pad stay in additon to normal operation requirements The Flight Computer shall collect video of the flight experiment during microgravity The Flight Computer shall collect Launch Vehicle position data and environment conditions (e.g. acceleration). Source Verification Design Method Feature Status USLI Handbook 1.7 Testing Power Supply In Progress MSC-3 Testing Camera In Progress MO-4 Testing IMU, PS In Progress eorgia Institute of Technology 29 of 187

30 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status FA-4 The Flight Avionics shall downlink telemetry necessary to a round Station for the recovery of USLI Handbook 2.11 Teting PS, round Station, Xbee In Progress the Launch Vehicle FA-5 The PS coordinates of all independent Launch Vehicle sections shall be transmitted USLI Handbook Teting PS, round Station, Xbee In Progress to the round Station FA-6 The Flight Avionics shall operate on an independent power supply from the USLI Handbook 2.12 Inspection Power Supply In Progress recovery system Mission Profile Figure 3 illustrates the mission profile for Project L.S.I.M. In order to achieve the desired microgravity environment, the launch vehicle will continue through for one (1) second until deployment of the drogue parachute. This post-apogee delay will yield approximate 4.5 seconds of microgravity to perform the L.S.I.M. eorgia Institute of Technology 30 of 187

31 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW eorgia Institute of Technology Figure 3. Project 31 L.S.I.M. of 187 mission profile.

32 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 3. Launch Vehicle 3.1. Overview The purpose of the launch vehicle is to carry a scientific payload to one mile in altitude and safely return the vehicle to the surface of the Earth. Embracing innovative and out-of-the-box thinking, the launch vehicle will have the ability to carry a wide range of payloads, from scientific experiments to engineering flight demonstrations. A rib and stringer payload mounting rig enables easy integration for payload. The launch vehicle has a five inch outer diameter and is 9 feet, 10 inches in length. The launch vehicle is composed of three sections; the nose cone, the payload section, and the booster section. The science payload will be housed in the payload section of the rocket and the avionics will be housed in the booster section above the motor. The launch vehicle will utilize a dual-deployment recovery system that will minimize the drift of the launch vehicle by mitigating the effects of unpredictable wind conditions with a drogue chute descent. However, the overall purpose of the recovery system, to minimize damage to the launch vehicle from impact with the ground, will be maintained by a main chute deployed closer to the ground. The drogue parachute will be housed in the section connecting the booster and payload sections, while the main parachute will be located between the payload section and nose cone. Both parachutes are made of rip-stop nylon. To ensure successful chute deployment, redundant systems will be used. Each chute will feature two independent black powder ejection charges with corresponding redundant igniters and StratoLogger altimeters. The powder charges will be ignited using low-current electronic matches with independent power supplies at the command of the altimeters Mission Criteria The criteria for mission success are shown in Table 3. eorgia Institute of Technology 32 of 187

33 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 5: Mission Success Criteria Requirement Design feature to satisfy that requirement Requirement Verification Success Criteria The payload requires a steady, but randomly vibrating platform to test the L.S.I.M. system. Provide a suitable environment for the payload. Unsteadiness in the motor's thrust and launch vehicle aerodynamics cause vibrations. In addition, deployment of the drogue By measuring the acceleration with the payload's accelerometers. The L.S.I.M. system reduces a recordable amount of sloshing. parachute will be delayed one second to maximize time in microgravity. To fly as close to a mile in altitude as possible without exceeding 5,600 ft. A motor will be chosen to propel the vehicle to a mile in altitude. Through the use of barometric altimeters. The altimeters record an altitude less than 5,600 ft. Through finite The vehicle must be reusable. The structure will be robust enough to handle any loading encountered during the flight. element analyses and structural ground testing of The vehicle survives the flight with no damage. components System Design Overview lists the derived system-level requirements in order to meet the success criteria. The requirement numbers reference the requirements in the USLI Handbook. eorgia Institute of Technology 33 of 187

34 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 6: Launch Vehicle System Requirements Requirement No. Requirement Source Verification Method Design Feature Status LV-1 The Launch Vehicle shall carry a scientific or engineering payload. USLI Handbook 1.1, MO-2 Inspection imps standardized payload interface In Progress The maximum LV-1.1 payload weight including any supporting avionics shall not exceed 15 LV-1 Inspection Maximum Parachute Sizing In Progress lbs. The Launch Vehicle Three (3) shall have a sections: LV-1.2 maximum of four USLI Handbook 1.5 Inspection nosecone, In Progress (4) independent or payload, and tethered sections booster LV-2 The Launch Vehicle shall carry the payload to an altitude of 5,280 ft. above the ground. USLI Handbook 1.1, MO-1 Testing Modified tube fins for straight flight, motor sizing In Progress eorgia Institute of Technology 34 of 187

35 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. LV-2.1 LV-2.2 LV-2.3 LV-2.4 Requirement The Launch Vehicle shall use a commercially available solid motor using ammonium perchlorate composite propellant (APCP). The total impulse provided by the Launch Vehicle shall not exceed 5,120 N-s. The Launch Vehicle shall remain subsonic throughout the entire flight. The Launch Vehicle shall carry one commercially available barometric altimeter for recording of the official altitude Source Verification Design Method Feature Status Use of a USLI Handbook commercially Inspection 1.11 available In Progress solid motor A motor with a maximum USLI Handbook Inspection motor class of 1.12 "L" shall be In Progress used USLI Handbook 1.3 Analysis Motor Sizing In Progress Commercially USLI Handbook 1.2 Inspection available In Progress altimeter eorgia Institute of Technology 35 of 187

36 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The amount of LV-2.5 ballast, in the vehicle's final configuration that will be flown in Huntsville, shall be no more than 10% of the unballasted USLI Handbook 1.14 Inspection Proper motor selection for gross lift-off weight of the launch vehicle. In Progress vehicle mass. The Launch Vehicle LV-2.5 shall have aerodynamic stability margin of 1.5 to 3 cailbers prior to leaving the LV-2 Analysis Modified tube-fins for aerodynamic stabilization. In Progress launch rail. Parachute The Launch Vehicle Sizing and LV-3 shall be safely recovered and be MSC-7.1 Testing real time round In Progress reusable. Station tracking The Launch Vehicle round LV-3.1 shall contain redundant USLI Handbook 2.5 Inspection testing of altimeter In Progress altimeters. ejection. eorgia Institute of Technology 36 of 187

37 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The recovery LV-3.2 system shall be designed to be LV-3 Inspection Arming Switches In Progress armed on the pad. The recovery LV-3.3 The recovery system electronics shall be completely independent of the payload electronics. USLI Handbook 2.4 Inspection system electronics shall be entirely independent of from all In Progress other systems. Each altimeter shall be armed by a Recovery dedicated arming system design switch which is shall accessible from the incorporate LV-3.4 exterior of the USLI Handbook 2.6 Inspection one (1) In Progress vehicle airframe independent when the vehicle is arming switch in the launch for each configuration on the altimeter launch pad. eorgia Institute of Technology 37 of 187

38 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status Recovery system design shall Each altimeter shall incorporate LV-3.5 have a dedicated USLI Handbook 2.7 Inspection independent In Progress power supply. power supplies for each altimeter. The arming Each arming switch switches will shall be capable of be designed to LV-3.6 being locked in the USLI Handbook 2.8 Testing use a key to In Progress "ON" position for change the launch. state of the switch. Arming LV-3.7 Each arming switch shall be a maximum of six (6) feet above the base of the Launch Vehicle. USLI Handbook 2.9 Inspection switches shall be located near the booster section of the launch In Progress vehicle eorgia Institute of Technology 38 of 187

39 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The Launch Vehicle Utilization of LV-3.8 shall utilize a dual deployment USLI Handbook 2.1 Inspection a drogue and main In Progress recovery system. parachute Removable shear Plastic shear pins shall be used pins will be LV-3.9 for both the main and drogue USLI Handbook 2.10 Inspection installed in the recovery In Progress parachute compartments compartments. LV-3.10 All sections shall be designed to recover within 2,500 ft. of the launch pad assuming 15 MPH winds. USLI Handbook 2.3 Analysis Parachute sizing will incorporate descending velocities and drift restrictions. In Progress Properly sized LV-3.11 Each section of the Launch Vehicle shall have a maximum landing kinetic energy of 75 ft-lb f. USLI Handbook 2.2 Analysis main parachute to ensure landing kinetic energies below 75 ft.- In Progress lb f eorgia Institute of Technology 39 of 187

40 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status Proper shielding The recovery shall be system electronics incorporated LV-3.12 shall be shielded from all onboard LV-3 Testing into the design to In Progress transmitting protect the devices. electronics from payload interference. LV-4 The Launch Vehicle shall be launched utilizing standardized launch equipment LV-3 Inspection Use of standard 1515 rail buttons and 8 foot launch pad rail. In Progress The Launch Vehicle shall be capable of being launched by a standard 12 volt direct current (DC) Use of LV-4.1 firing system and USLI Handbook 1.9 Testing standard In Progress shall require no igniters. external circuitry or special ground support equipment to initial launch. eorgia Institute of Technology 40 of 187

41 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The Launch Vehicle LV-4.2 shall not require any external circuitry or special ground support equipment to initiate the launch other than what is provided by the USLI Handbook 1.10 Testing Use of standard igniters, 1515 rail buttons, and 8 foot launch rail. In Progress range. The Launch Vehicle Follow LV-4.4 shall have a pad stay time on one (1) USLI Handbook 1.7 Testing manufacturers recommendati In Progress hour. ons for power LV-4.5 The Launch Vehicle shall be capable of being prepared for flight at the launch site within two (2) hours from the time the waiver opens. USLI Handbook 1.6 Testing Easy assembly of the rocket structure and easy integration of the payload and avionics. In Progress eorgia Institute of Technology 41 of 187

42 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement No. Requirement Source Verification Method Design Feature Status The Launch Vehicle shall be compatible with either an 8 foot Utilization of LV-4.6 long, 1 in. rail (1010), or an 8 feet USLI Handbook 1.8 Testing 1515 rail and rail interfaces In Progress foot long, 1.5 in. rail for launch (1515), provided by the range Recovery System The purpose of the recovery system is to minimize damage to the launch vehicle from impact with the ground. The launch vehicle will use a dual-deployment recovery system to mitigate the effects of unpredictable wind conditions on drift with a drogue chute descent. The drogue parachute will be housed in the compartment connecting the booster and payload sections, and the main parachute will be located between the payload section and nose cone, as illustrated below in Figure 4. The launch vehicle will be armed on the launch pad using two arming switches, one for each independent altimeter and ejection charge. For the purpose of simulation, the launch vehicle has been modeled using the Open Rocket Software, with both parachutes made of rip-stop nylon. eorgia Institute of Technology 42 of 187

43 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 4: Internal Layout of the Launch Vehicle During descent, 30 feet of Kevlar webbing will connect the parachutes to the launch vehicle. The drogue parachute will be housed in a cylindrical compartment in the rear section between the payload and booster sections as illustrated in Figure 4. This compartment has an outer diameter of 5.25 inches and a length of 10 inches. A bulkhead in the rear payload section will house the ejection wells and also serve to take the impulse of the gun powder blast. The drogue parachute s retention mechanics includes a U-Bolt placed between the two ejection wells on the underside of the payload section, as well as a U-Bolt in the booster section thrust plate. In addition, a shock cord connecting the booster section and main rocket body together. At deployment, the ejection charges will separate the booster section from the main rocket, releasing the drogue parachute as well. eorgia Institute of Technology 43 of 187

44 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 5: Drogue Parachute Assembly The main parachute will be placed in a section above the payload bay. The section has an outer diameter of 5.25 inches and a length of 12 inches. The main parachute s ejection wells will be placed such that the impulse is imparted on the payload section and the nose cone is separated from the main rocket pulling the main parachute out. Shock cords will connect the main parachute to the nose cone and the payload section of the launch vehicle, ensuring that the all sections remain together during descent. The main parachute assembly is illustrated in Figure 6. eorgia Institute of Technology 44 of 187

45 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 6: Main Parachute Assembly The parachute casings are made of 10 fiberglass, and the bulkhead under the main chute is made of plywood. Two-inch stainless steel U-Bolts will be drilled into the bulkheads, and will be used to attach the shock cords. 1/16 nylon rod will be used as the four shear pins to keep both the main and drogue chute compartments together during flight until the parachutes are deployed. PVC end-caps will be used to direct the ejection charges in order to protect the casing from thermal shock, and a NOMEX shield will protect the parachutes. The charges will be ignited using an e-match Altimeters To ensure successful chute deployment, redundant systems will be used. Each chute will feature two independent black powder ejection charges with corresponding redundant igniters and StratoLogger altimeters. The altimeters will ignite the ejection charges through the use of lowcurrent electronic matches using independent power supplies. The components which compose eorgia Institute of Technology 45 of 187

46 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW each altimeter system are independent of all payload electronics. The altimeters and all recovery electronics have a pad stay time of at least an hour. The system setup for each altimeter is shown below in Error! Reference source not found.. The electrical drawing for the wiring harness is located in Appendix VI. Figure 7: Electronic Altimeter Schematic In addition, the recovery electronics wiring will be protected from transmitting devices in the rocket through faraday cages and shielding integrated into the wiring harnesses, these devices are discussed further in the Avionics. round testing will determine whether transmission interference will affect the altimeter devices directly Arming Switches The altimeters and the recovery systems will be activated on the launch pad with two arming switches. Each arming switch activates one of the two independent altimeter systems. The arming switches will be located at the base of the payload section which is approximately four feet above the bottom of the launch vehicle. The arming switches will be Featherweight Screw Switches and is illustrated below in Figure 8. The Screw Switches are locked in the ON position when the middle screw is screwed in and completes the circuit. In addition to having a simple activation and de-activation method, the Screw Switches are very lightweight and small. eorgia Institute of Technology 46 of 187

47 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 8: Featherweight Screw Switches Parachute Dimensions The sizing of the main parachute is determined by the weight of the launch vehicle and the kinetic energy constraint of the launch vehicle when it touches down. Based on the LV-3.10 and LV-3.11 requirements, the launch vehicle should not experience more than 75.0 ft-lbf of kinetic energy upon landing, this places an upper limit on the landing velocity to be approximately ft/s. The main parachute is 12 feet and the drogue parachute is two feet. Table 7 and Table 8 outline the dimensions and properties of the constraining launch vehicle properties and the properties of the parachutes. eorgia Institute of Technology 47 of 187

48 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 7: Launch Vehicles Properties Launch Vehicle Properties Weight of launch vehicle 45 lb C D of Launch vehicle 0.75 Max Kinetic Energy 75.0 ft-lbf Table 8: Recovery System Properties Properties Main Parachute Drogue Parachute Diameter (ft) 12 2 Surface Area (ft^2) Estimated C D Target Descent Rate (ft/s) Drift Profile Analysis Drift profile analysis is the method used to estimate and constrain the landing site for the launch vehicle. Based on how long the launch vehicle will be in flight and the wind speed at launch, the range can be estimated. Using the equations below, the drift of the launch vehicle under the main and drogue parachutes can be determined. The results are shown below in Table 9 Drift = Time in flight V wind (1) Time in flight = Alt max descent speed (2) descent velocity = 2mg ρac d (3) eorgia Institute of Technology 48 of 187

49 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 9: Drift Estimates Launch Vehicle Drift Estimates Wind Speed Drift (ft) (mph) Drogue Parachute Main Parachute Total Drift The descent velocity of the launch vehicle will be estimated using the terminal velocity. The terminal velocity is the constant speed of a free-falling object when the drag due to air resistance prevents further acceleration. The values are listed below in Table 10. Table 10: Recovery Characteristics Recovery Systems Properties Drogue Parachute Main Parachute Diameter (ft) 2.00 Dimensions (ft) Flight Time (s) Flight Time (s) Terminal Velocity (ft/s) Terminal Velocity (ft/s) Horizontal Drift (ft) Horizontal Drift (ft) Total Drift (ft) eorgia Institute of Technology 49 of 187

50 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Kinetic Energy of Launch Vehicle Kinetic energy calculations were performed using the equation below. KE = 1 2 mv2 (4) Using the masses of the separate sections, the kinetic energies can be calculated using the velocity of the system at different points in the mission. The Kinetic Energies of separate sections after the drogue chute is deployed are given below in Table 11. After the drogue chute is deployed, the launch vehicle has separated only between the booster section and the payload section, so the payload and nosecone sections are treated as one part. The velocities listed are the terminal velocities under the drogue parachute once the Table 11: Kinetic Energy at Drogue Parachute Deployment Launch Vehicle Section Weight (lb.) Velocity (ft/s) Kinetic Energy (ft-lbf) Nose Cone Payload Booster The Kinetic Energies of the separate sections after the deployment of the main chute and landing are given below in Table 12. After the main chute is deployed all three sections have separated and their separate masses were used in the calculations. All sections will have the same velocity due to the shock cord tethers. eorgia Institute of Technology 50 of 187

51 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 12 : Kinetic Energy at Main Parachute Deployment Launch Vehicle Section Weight (lb.) Velocity (ft/s) Kinetic Energy (ft-lbf) Nose Cone Payload Booster Ejection Charges To eject the parachutes, redundant black powder charges will be used. The containers housing the chutes will also be pressurized in order to ensure chute deployment. Due to the different requirements for the drogue and main chutes, two sets of calculations will be needed. The amount of black powder used in the ejections charges can be calculated through Equation (5) below. Once the amount of black powder is determined the values can then be tested before flight. The equation relates weight of black powder to the ejection pressure, volume of the container, black powder combustion gas constant, and the black powder combustion temperature. The constants used are listed below in Table 13. Pressure Volume lb of Black Powder = (5) RT Using the pressurization of 10 psig and 9 psig as a structural maximum for the main and drogue chute compartments, the resulting black powder masses are calculated to be 5 grams and 2 grams for the main and drogue chutes, respectively, as illustrated below in Table 14. The masses used will depend on the final container dimensions, which were estimated at 5.25 inches in radius and 12 and 10 inches in length for the main and drogue, respectively. The force required for separation with the given number of Nylon shear pins would be 446 lb f for the main chute and 393 lb f for the drogue chute. eorgia Institute of Technology 51 of 187

52 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 13: Black Powder Properties Constant Combustion as Constant Combustion Temperature Value ft lb f / lb m R 3307 R Table 14: Black Powder Masses Main Drogue Total Pressurization 10 psig 9 psig Ejection force 446lbf 393lbf Black Powder 5 grams 2 gram Testing In order to ensure the safety and viability of the calculations made in determining the black powder masses, ground testing was completing before flying the launch vehicle recovery system. The black powder testing was successfully conducted on the Vespula Mk II rocket. Since the recovery sections of the Intimidator 5 kit and the Vespula Mk II are identical, the recovery system of the Intimidator 5 kit is validated. Due to the explosive nature of black powder charge testing, the tests for this launch vehicle were coordinated with the campus security and the eorgia Tech Fire Marshal. For the black powder test, the rocket was placed horizontally on the ground on a relatively smooth surface to minimize unwanted static friction irrelevant to a flight environment. Table 15 lists the conditions for test success and failure. eorgia Institute of Technology 52 of 187

53 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 15: Success Criteria Success Criteria Ejection charge ignites Shear pins break Launch vehicle moves half the distance of shock cord Table 16: Failure Modes Failure Criteria The fiberglass of the tube coupler shatters due to the charge. The shear pins don t shear, and the launch vehicle stays intact. The NOMEX/cloth shield fails and the parachute is burned. The E-matches fail to ignite the black powder Structure The purpose of the launch vehicle is to carry a microgravity research payload to a mile in altitude and safely return to the surface of the Earth. Additionally, the launch vehicle will also be designed to carry a wide range of possible experiments, so that the rocket can be reused in the future. The overall design is to be as flexible as possible, encouraging reuse for future research and multiple launches. The rocket has been constructed and is ready for a test launch scheduled for Saturday, March 23 rd. The objective of the test launch is to verify the recovery system with delayed apogee ejection and to collect preliminary acceleration data from the REFP payload. The launch vehicle is a Performance Rocketry 5 inch Intimidator kit. The construction was carried out by the Rocket Team, under the Supervision of Richard Zappulla, an experienced and certified Level 2 High-Powered Rocket flyer. The payload is designed around the constraints of the vehicle payload section, which are five inches in diameter and 30 inches in length. eorgia Institute of Technology 53 of 187

54 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Construction The launch vehicle has a 98mm motor mount and adapters for both a 54mm and 75 mm motor have been constructed to allow for a wide range of useable motors. The kit is made of all fiberglass for strength and durability. The tubing is 1/16 in. thick, the centering rings and bulkheads are 1/8 in. thick, the fins are 3/16 in. thick and factory beveled, and the nosecone is constructed of fiberglass. The fins are attached with through-wall construction and securely bonded to the motor mount and body tube with fiberglass-reinforced epoxy. The fins transmit most of the force from the motor to the booster section, so the centering rings are not critical, however they are bonded using the same techniques used for the fins. The fiberglass, at all fiberglass-epoxy joints, was scuffed with 80 grit sandpaper to create a good bonding surface. US Composites epoxy is reinforced with chopped (1/4 in.) or milled (1/16 in.) fiberglass filler and fumed silica filler was used for all structural bonds on the rocket. The recovery system attaches to the booster section with a length of 1/4 in. steel cable (wire rope) rated for 6000 lb. breaking strength. Steel cable was used instead of a U-bolt because of the small clearance between the 98mm motor mount and the 5 in. body tube. A loop of cable extends through the centering ring, and a 1 foot section on either side is epoxied to the motor mount. This method has been tested on other rockets and is at least as strong as the U-bolt bolted to the centering ring. The long length of cable allows the force of the recovery system to be distributed over a very large area of the motor mount tube compared to a relatively small area of a centering ring. For a redundant recovery system attachment and a redundant motor retention, a tapped forward closure will be used in addition to the cable attachment point. The rocket was not built with a "ziperless" design because of the limitations that it would impose including motor length and payload volume. A zipper is unlikely because the tubing is all fiberglass. The attachment points to the payload bay use a more traditional U-bolt attachment. The U-bolts are bolted through two doubled up 1/8 in. bulkheads for a total of 1/4 in. of fiberglass, and steel fender washers are used on the back to further spread out the load from the recovery system. eorgia Institute of Technology 54 of 187

55 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The bulkhead assembly will be bolted to the end structural plates of the MPS assembly. All U- bolts are 1/4 in. steel rated for over 2000 lb. breaking strength. The shock cord is one inch nylon webbing rated for 4000 lb. and will be attached to the other components of the recovery system with 1/4 in. steel quick links rated for at least 2000 lb. A length of shock cord is epoxied directly to the nose cone as opposed to sealing it with a bulkhead to allow the addition of weight for final adjustment, and to allow the installation of electronics in future missions Payload Integration The payload will be integrated using a rib and stringer design. The stringers will be three #8 threaded rods and the ribs will be made of plywood. The ribs will be secured using #8-32 nuts and #8 washers on both the top and bottom of each rib. This flexible design allows for the ribs to be moved based on the needs of the science payload. At the top and bottom of the payload integration structure are two half inch plywood bulkheads. The bulkheads are attached to the body of the rocket using four L-brackets on both the top and bottom of each bulkhead. There is a total of 16 L-brackets on the payload section bulkheads. The payload integration structure is pictured below in Figure 9 with L.S.I.M. specific integration already components mounted. Figure 9: Payload Integration Structure Avionics Integration Due to the relatively short payload section of the Intimidator 5 kit the avionics will be mounted in the booster section above the motor. Similarly to the payload integration structure, the avionics integration structure is composed of a bulkhead and a rib separated by three #8 threaded eorgia Institute of Technology 55 of 187

56 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW rods. The bulkhead is secured by 8 L-brackets, four on the top and four on the bottom, and features a steel U-bolt to secure the drogue parachute. The rib is secured using four L-brackets on the bottom side. The avionics integration structure is pictured below in Figure 10. Figure 10: Avionics Integration Structure Section Integration The three sections of the rocket, namely the nose cone, payload, and booster sections, will be separated by two parachute bays made of -10 fiberglass. These bays, one for the drogue parachute and the other for the main parachute, will serve as structural elements as well as sealed compartments for recovery purposes. At the end of each section is a sealing bulkhead with a U- bolt to which adjacent sections of the launch vehicle are tethered, in addition to recovery devices Launch Vehicle Performance Analysis Altitude Predictions and Motor Selection Mission performance predictions are based on a projected rocket mass of approximately 15.7 kg. This estimate does not include the mass of the motor case and propellant. However, the mass of the rocket motor case and propellant is factored into the flight performance simulations that have been conducted. The motor selected for flight, which will result in the vehicle attaining the eorgia Institute of Technology 56 of 187

57 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW target altitude, is an Aerotech L1390. The Aerotech L1390 has a total impulse of Ns and will keep the launch vehicle sub-sonic throughout flight. Altitude simulations were performed in Open Rocket on a model representing the launch vehicle's dimensions, mass, and Center of ravity (C) location. Table 17 below lists the altitude output from various simulations. Additionally, Figure 11 is a plot of altitude and thrust versus time for the selected flight motor. Table 17: Altitude as a Function of Motor Selection (Constant Dry Mass) Rocket Mass (without motor) Motor Altitude (ft) 15.7 kg L1390 (Aerotech) 5, kg L1720 (Cesaroni) 5, kg L1482 (Loki) 5, kg L1520 (Aerotech) 5, kg L1355 (Cesaroni) 5,190 eorgia Institute of Technology 57 of 187

58 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 11: L1390 Altitude and Thrust vs. Time eorgia Institute of Technology 58 of 187

59 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Stability At liftoff, the rocket has a stability margin of 2.3 calibers. The motor selected for flight provides a launch rail exit velocity of 65 ft/s, which is sufficient for stability. The C versus Center of Pressure (CP) (or stability margin) for the flight is plotted below in Figure 12. The stability margin increases to approximately three calibers during the coast phase of flight. Regarding sensitivities, simulations were produced with wind speeds up to 20 MPH. At the maximum tested wind speed, the lowest simulated maximum altitude was 5,200 feet, and the lowest launch rod exit stability margin was 0.75, with a coast phase margin of 2.5. Figure 12: Launch Vehicle Stability vs. Time eorgia Institute of Technology 59 of 187

60 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Testing The sub-scale launch tested the Vespula Mk II modified tube fin design. The successful subscale test occurred on Saturday, October 13 and is illustrated below in Figure 13. The modified tube fin design was de-scoped when the switch to the Intimidator Kit was made. Figure 13: 45% Scale Test Rocket and Flight At this time, the competition launch vehicle has not been flown due to previous in-flight failures of the Vespula Mk II launch vehicle. The test flight of this vehicle will be completed before the FRR telecom, and additional vehicle data will be presented during the presentation. The presentation will include a drag assessment and the comparison and validity between flight results and predicted results obtained via analysis tools. eorgia Institute of Technology 60 of 187

61 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 3.6. Intimidator 5 Kit Mass Breakdown The mass breakdown for the Intimidator 5 Kit is illustrated below in Table 18 and the landing masses for the Intimidator 5 Kit are illustrated below in Table 19. The graphical breakdown of the landing masses are illustrated below in Figure 14. The values obtained for the booster, payload, and nosecone sections were obtained through weighing each section individually while everything was assembled with the exception of the motor. In addition, the values for the drogue chute, main chute, shock cords, and the motor case are also actual weights obtained from a scale. Table 18: Overall Weight Breakdown Component Weight (lb.) Quantity Total Weight (lb.) Booster Payload(w/ nosecone) Main Parachute Drogue Parachute Shock Cord Motor Motor w/out propellant Science Avionics Total Take-Off Weight eorgia Institute of Technology 61 of 187

62 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 19: Intimidator 5 Kit Landing Masses Section Landing Mass (lb.) Nosecone Payload Booster Total lb lb lb. Nosecone Payload Booster Figure 14: Intimidator 5 Kit Landing Mass Breakdown 3.7. Interfaces and Integration The interfaces between the launch vehicle and the ground, and ground launch system, shall be described such that the operation of interfacing the launch vehicle with these systems can be correctly carried out to ensure optimal launch vehicle performance, with maximum safety to the USLI team, and so that a sustainable architecture can be developed to show new members the necessary action items of launch vehicle/ground/ground launch system integration. eorgia Institute of Technology 62 of 187

63 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Interface with the round The launch vehicle will have a PS tracking system that will deliver real-time telemetry, as well as the launch vehicle s landing location, to the ground tracking station via an XBEE radio transmitter. When the power system is locked to the ON position on the launch pad, the XBEE will begin transmitting telemetry data Interface with the round Launch System The launch vehicle will have attached large launch lugs, so that it can fit within a launch rail with an aluminum 1515 T-slotted extrusion, of a minimum length of 8 feet. The launch vehicle will be placed on a launch stand designated by the LCO after being inspected and certified flight-worthy by the RSO. After proper assembly and insertion of the motor, inspection and certification, and attachment to the launch stand, the electronics necessary for the payload and recovery system, will be activated and locked into position. The altimeter will announce the readiness of the electronics and payload system via a series of beeps. The launch vehicle will be launch using standardized launch equipment including a standard 12 volt direct current firing system Launch Vehicle Operations It is the responsibility of Launch Operations to create comprehensive guides and checklists to ensure proper operation of the launch vehicle and the safety of the USLI team. Proper operation of the launch vehicle requires that certain protocols and procedures are observed by the Ramblin Rocketeers team during assembly and launch Launch Checklist The Launch Checklist ensures that all tasks necessary for a successful launch are completed and completed in the most efficient order. The Launch Checklist has both a performer and an inspector to ensure all tasks are completed correctly. In addition, there is a Troubleshooting Chart to address common problems when preparing and launching rockets. The Launch eorgia Institute of Technology 63 of 187

64 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Checklist remains largely unchanged from the previous year in which the launch vehicle was prepared for launch in one hour. Because of this the are confident that the time needed to prepare the launch vehicle for launch will remain well below the two hour requirement, LV-4.5. The Launch Checklist can be found in Appendix II. eorgia Institute of Technology 64 of 187

65 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 4. Flight Experiment 4.1. Introduction to the Experiment and Payload Concept Features & Definition With the rise of entrepreneurial space flight, many new exotic spacecraft are being designed for the purpose of finding a profit in space. Many of these spacecraft will be equipped with liquid fuel propulsion and attitude control systems, or will seek to store large quantities of liquid propellant. These liquids present difficulties in the design and operation of a spacecraft because in low gravity, the fluids will be dominated by a combination of capillary/inertial/gravity gradient forces and will respond to perturbations. The response of stored liquids to such perturbations is termed slosh, and slosh is known to 1) alter the inertia matrix of a spacecraft and 2) to hamper the use of vents and propellant feed lines. Some methods of controlling slosh are listed in Table 20. Table 20: Methods currently available for damping slosh. Damping Method Description The choice of tank geometry (cylindrical, spherical, toroidal, etc) is known to Tank geometry have an impact on slosh damping through viscous effects. Annular disks along the circumference of a tank that impede slosh and may be Ring baffles given various camber geometries. Lids and mats Lids and mats float on a free surface of the liquid and impede slosh. Floating cans Cans impede slosh by absorbing and dispersing the kinetic energy of the liquid. Expulsion bag or Bags and diaphragms reduce slosh by containing the propellant and forcing it diaphragm into propulsion feed lines. Non-ring baffles are baffles that do not necessarily follow a tank circumference, Non-ring baffles e.g. cruciform baffles. Flexible baffles are baffles made of flexible materials that deform under the Flexible baffles inertia of sloshing liquids. While present methods of reducing slosh may be very effective in some flight regimes, there are design issues inherent to some of these systems. For baffles perhaps the most effective eorgia Institute of Technology 65 of 187

66 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW dampers for the additional inert mass instabilities can occur during launch if propellant levels are below the lowest baffle as in the case of the Saturn I. Similarly, such problems could occur in low gravity situations where the baffles are rendered ineffectual from lack of contact with the liquid. However, with the expense of mechanical complexity and inert mass, expulsion bags and diaphragms can be used to avoid such instabilities. The intend to provide another alternative solution by demonstrating the use of magnetorheological (MR) fluid as a moveable, deformable baffle and potentially a diaphragm equivalent Accomplishments Since CDR Since CDR, the team has pushed forward with hardware development. Despite delays due to shipping and receiving of parts, as well as longer-than-predicted manufacturing times, ground testing is about to begin and should be completed before April. A full science payload for the rocket is on track to be completed on April 2, just before the REFP Technical Experiment Data Package deadline of April 3. Additionally, a science package was flown on the first test flight, giving important insight to improve the science payload data acquisition. A second, upgraded package more similar to the electronics that will be flown on the flight at Huntsville launched on March Important Changes All use of cameras for the science payload has been de-scoped. Bench-testing of the solenoid control system is prioritized over the two-plate testing, so that important progress is made towards finalizing both the USLI and REFP payloads Test Launch Lessons Learned Summary of Science Team Payload The science team flew an Arduino Mega, OpenLog, and two piezo-electric vibration sensors to obtain preliminary data on the launch vehicle environment. The power supply was a 6V AA eorgia Institute of Technology 66 of 187

67 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW battery array with DC connector. Payload tubes for the purpose of mass simulation were also flown but were not within the scope of the science team interests of the full-scale test flight Report of Failures and Occurrences Integration The science electronics suffered a lack of integration consideration in design. A vertical integration scheme was necessary for the Arduino Mega, however the protoboard shield and power supply had cumbersome dimensions and securing these items increased the risk of failure. A protoboard pieces was cut unnecessarily, endangering solder joints. Finally the Mega was mounted vertically with duct tape and redundant zip-ties, securing it to the rocket structure Sensor detachment A sensor was observed to have been detached from the terminals at some point during the tumbling phase of the rocket trajectory. However, this sensor appears to have had its supporting circuitry shorted to Arduino ground because of the manner of integration and a lack of electrical tape on the Mega USB B header. The result was saturated readings of the secondary (radial) piezo-electric sensor. This was a non-critical failure Openlog File Writing A secondary file was begun at some point in the writing of data. There is no time-step matchup between these files. Thus it is difficult to understand where in the timeline of the launch vehicle trajectory that the open log reset. This is a potential failure risk for the SIDES nodes that could disrupt the coherence of time data. The data are still available for analysis but are made difficult to interpret Results and Future Mitigation Integration Results eorgia Institute of Technology 67 of 187

68 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW One of the two zip-ties where broken during the spin of the launch vehicle. Fortunately a second zip-tie provided redundancy. Integration systems resistant both to typical axial loads and potential rotational loading should be considered for future launches Sensor data Sensor data was recovered and is being analyzed. The data recovered are presented in Figure 15 and Figure 16. Figure 16: FFT of corrected data showing peak Figure 15: Correcting for Piezo drift around 26 Hz Sensor data might be improved by better mating of the sensors to the mounting brackets or rocket structure. The data show strong peaks and piezo drift and should be useful in comparison of future datasets OpenLog Risk Mitigation To mitigate the risk of openlog errors i.e. starting to write a new file with dissimilar time stamp or other issues that might arise unexpectedly in the SIDES network, as well as to better analyze the data, an accelerometer will be flown on the science board so that the launch vehicle accelerations can be precisely correlated with vibration data. eorgia Institute of Technology 68 of 187

69 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 4.3. Science Background A complete science background is included in Appendix III Important Highlights In the science background, several important relationships are developed. These relationships are given in Table 21. Table 21: Elements of the theoretical modeling for the LSIM payload LSIM element Response of MR fluid to a magnetic field (motion as it rigidifies) Relationship Longitudinal Slosh Model Lateral Slosh Model Damping of MR Fluid if it is a rigid baffle L = g b 2 m ΔL k m L gk θ = (kl + mg) θ b 1 θ m By experiment and in correspondence with reference material tabulated data and plots Damping of From reference material, Container δ = 4.98ν 1/2 R 3/4 g 1/ Experiment Requirements and Objectives Success Criteria Minimum and maximum success criteria have been defined for the LSIM payload. Table 22 lists these criteria. eorgia Institute of Technology 69 of 187

70 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 22: LSIM success criteria from the Requirements Verification Matrix Minimum Maximum LSIM Success Criteria Successfully record video of flight experiment during microgravity and start/stop the experiment without mechanical and electrical failures. Successful matching of the damping ratio for ringed baffles in the wave amplitudes experienced during flight to within ±30% Requirements The requirements set for the LSIM experiment to satisfy both the goals of and the USLI requirements are listed in Table 23. Flight systems (experiment and avionics) are now budgeted to be 15 lbf. Table 23: LSIM Requirements Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document FS-1 The flight systems team shall design and build the LSIM MO-3 Inspection LSIM payload In Progress MO-3 Payload FS-2 The LSIM payload shall be designed to fly on a SLP rocket USLI Handbook Inspection LSIM payload In Progress USLI Handbook FS-4 The Flight Systems Team shall produce a working system for manipulating MR MSC-3 Testing Solenoids and Control Algorithms In Progress MSC-3 fluid in LSIM. eorgia Institute of Technology 70 of 187

71 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document FS-5 The Flight Systems Team shall ensure that all avionics are properly shielded from the LSIM payload. MSC-3 Testing Faraday cages and webbing tied to ground on the harness Not Started MSC-3 FS-6 The Flight Systems Team shall design all LSIM components and avionics such that they may be easily integrated with MSC-3 Inspection Mounting system Complete MSC-3 the Modular Payload System of the payload bay in the rocket. FS-7 The Flight Systems Team shall conform to all weight, power, and dimensional MSC-3 Analysis TBD In Progress MSC-3 requirements as per the rocket design. eorgia Institute of Technology 71 of 187

72 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document FS-7.1 The Experiment and Avionics, with mechanical supports, shall weight no more LV-1.1 Inspection TBD In Progress LV-1.1 than 15 lbf. FS-8 The flight computer shall execute all tasks necessary to the operation of the MSC-3 Inspection Maple SIDES node In Progress MSC-3 LSIM payload and avionics. FS-9 The LSIM payload shall have a dedicated power MSC-3 Inspection SIDES node In Progress MSC-3 supply. FS-10 The Flight Systems Team shall ensure redundancy and reliability of all MSC-3 Inspection SIDES network In Progress MSC-3 internal electrical hardware. eorgia Institute of Technology 72 of 187

73 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document FS-11 The Flight Systems Team shall provide for payload operation with up to 1 hour of wait on the launch pad and 2 hours of USLI Handbook 1.6 Inspection TBD In Progress USLI Handbook 1.6 wait during preparation of the Rocket. FS-12 The Flight Systems Team shall provide for electrical operations to begin at MSC-3 Inspection TBD In Progress MSC-3 the beginning of the flight trajectory. FS-13 The Flight Systems Team shall ensure that the LSIM payload is shut down safely during the MSC-3 Inspection TBD In Progress MSC-3 deployment phase of the flight trajectory. eorgia Institute of Technology 73 of 187

74 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document FS-14 Data from the LSIM payload shall be collected, analyzed, and reported by the team using the USLI Handbook 3.2 Inspection Data logging in SIDES network In Progress USLI Handbook 3.2 scientific method. FS-15 The LSIM payload will be designed to be recoverable and be able to launch again on the same day without any repairs USLI Handbook 3.5 Inspection Appropriate mounting to the payload interface. In Progress USLI Handbook 3.5 or modifications Hypothesis and Premise The hypothesis posed in the LSIM experiment is that If a baffle can be manipulated during the flight of a spacecraft, then unstable slosh can be actively damped. The experiment will apply radial magnetic fields to the propellant tank to manipulate and rigidify the MR fluid during the microgravity phase of the launch vehicle trajectory to perform Liquid Stabilization in Microgravity LSIM. The launch vehicle ascent will provide a high vibrational intensity environment in which to test the anti-slosh system. Furthermore, the use of diaphragms and propellant bags are eliminated with the assumption that: Trading mechanical complexity for electrical complexity is preferable from a reliability standpoint. eorgia Institute of Technology 74 of 187

75 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Therefore, the will implement a design to apply these concepts to both the launch vehicle and REFP Experimental Method and Relevance of Data The experimental method for LSIM requires a multi-step approach for ground testing, flight testing, and REFP. The purpose of ground testing will be to characterize the shear stress behavior of MR fluid of different composition and magnetic field configuration, the manipulation of MR fluid, and preliminary data on slosh damping ability. Flight testing will provide actual data on the capability of the MR fluid system to dampen slosh, especially in the microgravity environment. REFP would seek to explore a big-picture system that actively attempts to remove any stray MR fluid as propellant simulant is pumped out of the tank. In any of the test cases, an optimal mixture of MR fluid will enable an application of active control to maneuver MR fluid into position in flight. The testing cases are organized by the team testing matrix for LSIM, which is designed to enable comparative analysis of the results and to verify completion of the data set. Following the scientific method, the test matrix outlines control experiments and baseline comparisons to develop a qualified understanding of MR fluid in the context applicable to LSIM. A summary of scientific method fulfillment is given in Table 24. eorgia Institute of Technology 75 of 187

76 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 24: Scientific method fulfillment for LSIM Method step Fulfillment Question What are options for electrically damping slosh? Research Study of MR fluid and a review of The Dynamic Behavior of Liquids in Moving Containers Hypothesis If a baffle can be manipulated during the flight of a spacecraft, then unstable slosh can be actively damped. Test round testing plan and test matrix, flight test, REFP Analysis Data examination, post-processing, and analysis Communicate SLP documentation and VTC Furthermore, in an improvement over previous experimental design, the team intends to fly a control experiment as part of the flight test, permitting greater validating capability for the effectiveness of the damping system Testing plan Overview To accomplish the objectives of LSIM, several distinct testing sequences are necessary. Key to the success of LSIM is ground testing, where MR fluid mixtures will be characterized and manipulated with solenoids. Following on these tests are the USLI flight test and separately the REFP project. However, at this juncture of the project some testing has been de-scoped, namely shake-table testing of the bench test platform to demonstrate slosh reduction in 1-gee. This test was de-scoped due to the complexity and time constraints of procuring an appropriate shake-table. eorgia Institute of Technology 76 of 187

77 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 25: Test sequences and descriptions, included options de-scoped since PDR Test Sequence Explanation Purpose MR fluid characterization A two-plate test To determine experimentally the viscosity performance of MR fluid mixtures. Bench testing Solenoid operations To develop a method of control for rigidifying and raising MR fluid within a canister. Descoped sequences Shake table testing Formerly, to test slosh reduction in 1-gee. Launch Vehicle test USLI flight test Control and experiment test inside the launch vehicle to determine comparative reduction in slosh. REFP Up-scaled testing and feasibility Microgravity University study of MR fluid slosh cooperative project reduction. A brief description of each testing sequence is given in Table 25 above and the relationship between these testing sequences is illustrated in Figure 17 below. eorgia Institute of Technology 77 of 187

78 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 17: LSIM testing logic, illustrating a simple relationship of information between the test sequences and emphasizing that they flow down from the pursuit of the LSIM hypothesis. round testing will serve four general purposes: (1) the creation of MR fluid, (2) the verification and validation of theory and control systems, (3) the characterization of MR fluid, and (4) the development of a working model for flight testing. For the successful completion of ground testing, the team will create an optimal mix of MR fluid. An optimal mix will depend on the fluid's balance between rigidity and fluidity for manipulation under a magnetic field, such that the MR fluid is easily moved to an appropriate location in the tank. Verifying the Ramblin' Rocketeers' solution and theory of using MR fluid as a baffle to dampen unstable slosh will go through two phases. During phase one, only MR fluid will be subjected to a magnetic field. Phase two will include water along with MR fluid being subjected to a magnetic field. The results from these phases will indicate whether the solution is feasible by observing the controllability of MR fluid by a magnetic field as well as observing differences between MR fluid and the propellant simulant. By characterizing the MR fluid, the team will understand the eorgia Institute of Technology 78 of 187

79 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW various properties of the MR fluid such as its exerted shear force and how it changes under a magnetic field. The characterization process will include testing the force and viscosity of the MR fluid and observing preliminary slosh damping. Finally, a working ground model will be developed using the results from (1), (2), and (3) with constraints for flight experimentation MR Fluid Creation and Validation of Theory MR fluid can be created from three ingredients: carrier oil, magnetic particles, and surfactant. Table 26 provides example MR fluid ingredients in the design space. Table 26: List of MR fluid ingredients Carrier Oil Magnetic Particles Surfactant Mineral Oil IRON100 Powder Citric Acid Nanometer particulate ferrofluid IRON325 Powder Oleic Acid FE Powder Soy Lecithin Fe304 M1 Powder For a preliminary ground test in search of better understanding the behavior of MR fluid thereby making more informed decisions on the design space the team opted to use mineral oil, IRON325 powder, and oleic acid. By trial and error testing, the team created a stable MR fluid mixture using the aforementioned ingredients. The team created two mixtures of differing viscosities. While some sources had presented the iron concentration as 60% by mass, the preliminary tests found it necessary to increase this percentage. The first mixture resulted to be too fluid with 17 grams of mineral oil, 1 gram of oleic acid, and 56 grams of IRON325 powder (76% by mass). The second mixture resulted to be too viscous with 16 grams of mineral oil, 1 gram of oleic acid, and 56 grams of IRON325 powder (77% by mass). The ingredients were measured using a scale accurate to a gram. Future measurements will use a more accurate scale. From trial and error testing, the team created an MR fluid testing matrix that will test every eorgia Institute of Technology 79 of 187

80 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW possible combination between ingredients as well as small deviations from the trial and error test. For example, the team will gradually decrease the iron percentage by mass while gradually increasing the mineral oil percentage until the optimal mixture a mixture that appears to be rigid enough to act as a baffle and manipulative enough to move readily has been attained. Each mixture will be static tested by neodymium magnets and good mixtures may be tested with solenoids as ground testing improves. Validation of theory and control of MR fluid will occur if there is a change in the MR fluid's viscosity under a magnetic field. Figure 18: Preliminary static testing of MR fluid mixtures in magnetic fields From the results of preliminary testing, the composition of MR fluid is likely to be changed to using carrier oil made of ferrofluid. Ferrofluid is a mixture nanometer-scale ferromagnetic particles in oil with a surfactant. However, unlike MR fluid, ferrofluid does not have as high a percentage of pure iron and does not rigidify in the same manner as MR fluid. As carrier oil, the team hypothesizes that ferrofluid will increase the mobility and useability of the MR fluid mixture; even with 60% and greater mass ratios of iron powder. Furthermore, smaller iron particulates may also increase the mobility of the MR fluid. reater mobility than the initial mixtures is preferred such that the MR fluid may be moved to the final baffle location using solenoids, and eventually for the mobility desired for REFP MR Fluid Shear Stress Characterization: Two Plate Test eorgia Institute of Technology 80 of 187

81 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The team will determine the shear stress MR fluid exerts inside and outside magnetic fields to better understand how to manipulate the MR fluid as desired. To determine the shear stress, the team will perform a two-plate test with and without magnetic field acting upon the MR fluid. This test was chosen because of its simplicity; other tests such as a barometer test were considered for measuring the MR fluid's viscosity and force they turned out too complicated to realize. The two-plate test consists of two plates: a bottom plate, which is fixed to the ground and a top plate, which is free to move. A load sensor will be placed on the top plate to measure the reaction force that is generated. The current plate choice is acrylic. Figure 19: Shear stress of a fluid using the two-plate test (Source: Wikipedia) A control test will be performed by only having two plates together with a load sensor on the top, moving plate to calculate the frictional force by the plates themselves. For accurate and consistent results, a mechanical pulling device will be used to pull the top plate. Once a control has been measured, a quantity of MR fluid will be placed between the two plates and the same procedure will repeat with and without the MR fluid under a magnetic field. These tests will characterize the force that MR fluid will generate when it is under a magnetic field and when it is free of a magnetic field. A complete ground testing plan description is included in the round Test Plan appendix. eorgia Institute of Technology 81 of 187

82 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Working round Model The team will develop three methods of MR fluid control: an array of solenoids, a movable solenoid, and a fixed solenoid. For the launch vehicle and REFP, solenoid arrays appear to be the best current option Sensors Piezo-electric vibration sensors will meaure the variation in the force applied to the mounting brackets Design review Viscosity Test Rig A two-plate test rig was designed to characterize the viscosity of MR fluid. The design of this test rig underwent many revisions in order to meet measurement and budget requirements. The objective of this rig is to measure the force of fluid acting on the plate and ultimately, the viscosity value of the MR fluid. The reaction force and the viscosity constant are related by the following equation: F fluıd A = ηv 0 (1) D In Eq.(1), A is the surface area of the plates, V 0 is the pulling velocity of the top plate, D is the distance between the plates, and η is the viscosity coefficient. The surface area of the plate is in 2, and the distance between the plates is estimated to be about.25 in. A motor is used to control the velocity, so V 0 is also known. F fluid is measured with a nichrome wire device. This device measures force through changes in resistivity induced by small changes in cross-sectional area resulting from tension in the wire. The measurement limits for this device are set by the accuracy of electrical interface hardware and calibration testing. eorgia Institute of Technology 82 of 187

83 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW One of the design requirements is to simulate a non-frictional surface. The aim is to ensure that the only force acting on the plate is the fluid s shear force. This is accomplished by adding railings between the plates and the base of the structure. Although the railings do not completely remove friction, they minimize it enough so that friction is negligible. Part drawings for the test rig are available in the Appendix. The drawings shows locations of the railings attachment points and the tap needed as well. The railings require a #8 type screw, and a ¼ in tap is needed for hard woods and acrylic sheets with this type of screws. The dimensions and locations of the features on these parts are mainly driven by two parameters: solenoid strength and test time. Because the magnetic strength of the solenoid decreases drastically as the distance increases, the plates need to be close to the solenoid base. This requires short railings. The group also wants to maximize the contact time between the plates and the MR fluid, so the plates are designed to be long and skinny. Solenoids are aligned along the length of the plate to produce a uniform magnetic field during testing. Construction of the test rig depends on a number of assumptions and is subjected to revision for alternative methods if necessary. First, super wood glue will be used to connect wood pieces. If this is not sturdy enough, elbow brackets will be used to connect the corners of the wood pieces. The motivation for using glue instead of brackets is saving money. Second, wood pieces and acrylic sheets will also be glued together with epoxy. This method is the norm for connecting wood to acrylic sheet, and it saves space and money. A #8 type screw will be used to tighten the railings to the woods and acrylic sheets. The railings attachment holes are designed to provide a bit of a leeway. Attachment holes on the structure pieces and test plates can be off by about.05 in. A motor will be used to pull the top plate. The motor will stand on a piece of wood that has been designed with a height that will perfectly align the motor with the top plate. The tolerance for the height offset is ±.04 in. String and hook will be used to round out the pulling mechanism. This testing rig was delayed due to the design process and the winter break. Ordering and construction are planned to begin coincident with CDR and testing could begin around the time of CDR VTC in late January. eorgia Institute of Technology 83 of 187

84 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW round Test MR fluid production and manipulation In order to meet the system functional requirements, the MR fluid must have certain properties and also adhere to certain standards. The fluid must be sufficiently rigid when magnetized to not shear significantly or break due to fluid slosh; however, the fluid must also not be excessively resistant to motion when moving and shearing against a wall, so that it may be moved into position by the magnets. It is known that the size of iron particles makes the largest difference in the rheometry of the fluid. For instance, one batch of low quality fluid that was created earlier during preliminary testing, with larger iron particles than is typical of MR fluids, was found to be extremely resistant to motion. Therefore, to find a high-quality fluid with intermediate properties, it is wished to test iron powders with particles of mean diameter between 0.1 µm and 10 µm. In addition, to ensure purity, we shall attempt to purchase all powders from well-known sources. For example, one option being explored is a purchase of carbonyl iron powder from BASF. For the carrier fluid, mineral oil or hydraulic oil are both known to be fairly typical choices; the properties of the fluid should not be significantly affected by which is chosen. The final choice of components and their proportions will be made based on the results of the two-plate testing, as well as qualitative experience from attempts to move the fluid by manually moving magnets. The MR fluid will then be manipulated by solenoids in a ground testing platform that permits the placement and use of solenoids to control the MR fluid. The foundation of the bench test is built from Maker Beam parts. This allows for great configurability and flexibility. Four 30 cm Maker Bars are the corner stands of the test rig; they are placed vertically about 20 cm apart from each other. Four 20 cm Maker Bars are placed horizontally in between the vertical 30 cm Maker Bars and are attached to give support. There are three thin acrylic plates: one acts as the main base and the other two have holes cut for the beaker to fit inside the plates. The base plate sits on 4 flat L Maker Beam brackets about 2 cm eorgia Institute of Technology 84 of 187

85 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW above from the base. The 4 L Maker Beam brackets are attached to the four 20 cm horizontal Maker Bars. The beaker is placed in the middle of the base acrylic plate and the solenoids are placed radially around the beaker on the base plate. Four 90 Degree brackets are used to hold the second plate 2 cm above the first plate. The second plate has a hole cut in the middle to allow for the beaker to pass through the middle. More solenoids can be placed around the second acrylic plate. The same is done with the third acrylic plate as was done with the second acrylic plate, but 4 cm above the first, base acrylic plate. This design using Maker Beam parts allows for future design modification and addition of parts. Once more data has been collected, the team can attach a vibration motor underneath the first base plate to simulate slosh. Solenoids can be added, moved, or removed from each of the three acrylic plates during testing as test results shed more light on what is needed for more accurate testing. The top two acrylic plates with holes in them can be moved up or down the 30 cm maker beam bars to adjust the height at which the solenoids interact with the beaker Hardware and build progress Sensing The damping coefficient of the slosh-reduction system will be estimated by measuring the anchor force decay1f2 of the experiment. At this moment, the sensors will be measuring the frequency and magnitude of these forces (i.e. vibrations). These sensors are considered as Experimental hardware. 2 On the recommendation of p. 108, The Dynamic Behavior of Liquids in Moving Containers: with Applications to Space Vehicle Technology. Ed. H. Norman Abramson. NASA, (NASA SP-106) eorgia Institute of Technology 85 of 187

86 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The sensors are piezo-electric elements which produce voltage as a function of deformation, especially deflections of the sensor tip. The base of the sensor is affixed to both the experiment canister and lower mounting hardware. The mounting hardware is designed to permit tip deflection in at least one direction. This configuration was tested on the USLI sounding rocket without any liquid within the rocket experiment canister and the data is still Figure 20: Piezo-electric sensor used for detecting 3 anchor force oscillations2f under review. At the time of writing, the method of sensing the reduction in slosh is open for revision pending further information. Figure 20 gives the sensor and the major dimensions the thickness is on the order of mm.3f4 To operate the sensors, a simple op-amp circuit has been selected, modeled, and built to limit the voltage and boost the current of the sensor so that a microcontroller, such as an arduino, may read the sensor data on analog input pins. The circuit is given in Figure 21. A prototype built for the USLI sounding rocket is given in Figure Image from Sparkfun, 4 Sensor datasheet: eorgia Institute of Technology 86 of 187

87 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 21: Piezo-electric sensor circuit. The sensor is modeled as a variable-voltage source at 300 Hz. While 300 Hz is a theoretical maximum for the reading speed of the microcontroller, data was logged at a rate between Hz. With six (6) canisters, six (6) of these circuits would be needed to measure the anchor force oscillations for each canister. The power supply for the op-amp is sourced from the microcontroller and does not need to interface directly from the aircraft. Figure 22: Top and bottom view of sensor prototype circuit. Leads soldered to the piezo-electric sensors are attached to the blue terminals, while pins go to the microcontroller for data logging and analog reading. This prototype supports two sensors and is approximately 3 inches by 5 inches. Final boards may be much smaller. Preliminary data illustrates voltage drift and may help with analysis of tip deflection should force magnitude be deemed important; however, variation of the raw data is currently under analysis for frequency spectra and to understand the change in spectra over time. It is current thought by the team that the change in spectra over the course of the experiment may illustrate the decay of the anchor force, as the momentum of the water is changing as a damped oscillation. The relative frequency of the resting structure surrounding the eorgia Institute of Technology 87 of 187

88 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW experiment in the sounding rocket is used as a baseline for that portion of the experiment; no such baseline of data currently exists for the aircraft, but may be available as a test case. The data collected from the test launch of the USLI sounding rocket on the prototype piezo-electric sensor circuit is given in Figure 23 and Figure 24. The analysis of this data is not finalized and the noise and peaks are not yet understood. An accelerometer will be added to the rocket payload for increased clarity it is not yet certain whether an accelerometer will be flown with the aircraft payload or whether the team will wish to log the provided aircraft acceleration data. eorgia Institute of Technology 88 of 187

89 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 23: data showing sensor drift and a method of correction by distributing the data around the overall mean. Figure 24: frequency spectrum for the entire dataset Solenoids eorgia Institute of Technology 89 of 187

90 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The solenoids for the experiment currently consist of 3 50-turn layers of 32 AW copper magnet wire for a total of 150 turns per solenoid. This is approximately 3 times more turns than necessary to produce the impedance needed to pull 10W at 5VDC, implying that the power draw will be lower due to greater impedance. This decision was made to increase the field strength generated by the solenoid. Solenoids may need to be resized if not enough power is available at the containment box panel also, not every canister within the containment box will have solenoids, especially if only six (6) canisters can be flown totally as the experimental controls must be included. An iron core is used inside of the solenoid diameter. The solenoids current constructed are manufactured by hand, and are classified as Experimental hardware for the aircraft. The solenoids would be controlled by solenoid drivers mounted to one or several microcontrollers. The currently selected driver is given in Figure 25. Figure 25: 4x4 solenoid driver. Two drivers can be linked together per microcontroller to control 32 solenoids 5 directly. Approximately 3 inches by 2 inches.4f 5 Image from Sparkfun, eorgia Institute of Technology 90 of 187

91 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Microcontroller Currently proposed as the microcontroller for the experiment is the Arduino Mega. It is not certain whether multiple microcontrollers will be necessary. If so a USB multiplexer may be required but is not yet chosen. The microcontroller is illustrated in Figure 26. Figure 26: Arduino Mega microcontroller with major dimensions Payload Relevance and Science Merit The top priority of the Flight Systems team during project development was to create a payload concept leveraging team expertise while pursuing achievable and NASA-relevant experiments. Previously, the project investigated moving oxygen gas with an electromagnet eorgia Institute of Technology 91 of 187

92 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW essentially a steady-state siphon for paramagnetic materials. The USLI team investigated active platform electromagnetic stabilization, developing control algorithms for magnetic levitation during flight. After review by Flight Systems and the eorgia Tech, the team decided that the most relevant primary payload would be to demonstrate the use of MR fluids in anti-slosh applications using technology development from the and eorgia Tech USLI experiments. Combining technologies from the previous projects, the new LSIM payload will demonstrate a possible method to combat propellant sloshing. The benefits of such an anti-slosh system would be most applicable in deepspace long-duration missions. In such missions, large quantities of fuel must be stored and/or transported with cargo/personnel. A major issue in low-gravity environments for propellants is sloshing, where fluid begins to float freely in space relative to the propellant tanks. Sloshing may cause loss of pressurization in propellant feed systems, potentially creating dangerous propulsion failures. The current solution is to create a moveable and deformable baffle from MR fluid. Using electromagnets, the controlled fluid may then be used to dampen the propellant oscillations. Systems might be needed to insure that the fluid is removed from the propellant, and a magnetic siphon could be used if the mixing between fluid and propellant is minimal. This is the basis for the REFP experiment discussed later in this document. enerally however, the LSIM experiment is a science and engineering payload that involves phenomena from several fields, primarily magnetism, rheology and viscous flow, as well as nearinviscid fluid dynamics. Among the goals of LSIM is to develop a scientific model encompassing all of the above fields in order to understand the interactions between the various components of the system. This will be achieved by combining theory with experimentation and testing. Data will be collected for variables such as MR fluid position, MR fluid shear stress, and simulant position and acceleration as a function of time, rocket acceleration, and electromagnet currents and positions. Collecting this experimental data will enable changes in the applied control scheme to be made according to the observed data, as well as allowing for refinement of the dynamic and scientific model of the MR fluid-propellant simulant system. A full explanation eorgia Institute of Technology 92 of 187

93 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW of the science of slosh and MR fluid relevant to LSIM is included in the Science Background appendix. For MR fluids, the primary focus of research in current years has been on the properties of the MR fluids themselves, and on their interactions with solid objects or containers, rather than on their interactions with other fluids. Therefore, the LSIM experiment should give insight into this less-studied subject. In addition to the above modeling, there are other scientific benefits of this experiment. The behavior of MR fluids in microgravity has been of significant interest, with the InSPACE experiment on the International Space Station being a large-scale investigation on this topic. However, engineering applications of the fluid specifically in microgravity do not seem to have been investigated to the same extent. Microgravity is one of the places where MR fluid is likely to be most effective, as settling of iron particles and thus degradation of integrity does not occur in the near-absence of gravity. Therefore, the LSIM experiment allows for investigation of actual applications of MR fluids in microgravity, as well as scientific modeling of the MR fluidsimulant dynamics REFP The were selected for REFP. Reporting on the progress of this portion of LSIM will be to the JSC Microgravity University and TEDP documentation REFP-Specific Design Work Containment Box The containment box serves the role of supporting loads from aircraft accelerations, supporting the experiment canisters, providing interfaces for electrical hardware, containing any leaks from the canisters, and providing access to the canisters in the case that the initial canisters may be exchanged for differently configured canisters during the flight. eorgia Institute of Technology 93 of 187

94 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The redesigned containment box is 4 long in the forward direction of the aircraft, 3 along the span, and 2 tall. An illustration of the current containment box idea is given in Figure 27. Figure 27: Ideas for the containment box, illustrating some support elements and a possible electrical conduit. According to the aircraft ICD, the eorgia Tech containment box could be placed near any of the panels, as all panels provide 115V AC and 28VDC. To simplify the design of the box, the lower components to mate the canisters to the box will be rescaled versions of hardware already designed for the USLI sounding rocket. These mounting brackets will be resized for a 4 -maximum diameter tube and will provide a lower support for the canisters. So that the canisters are not torqued by their own inertia, an upper support will be eorgia Institute of Technology 94 of 187

95 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW attached to the containment box lid that will drop over the top of each canister. Further supports and trusses will be added as needed to support the manage inertia inside the box. The box, internal supports, and brackets are classified as Experimental hardware. The design of the mounting bracket for the USLI sounding rocket, and therefore a smaller version of the bracket intended for use in the aircraft, is given in Figure 28. Figure 28: bottom mounting bracket for the USLI sounding rocket. A larger version is intended to be used in the containment box. This piece attaches to the box - a second part attaches to the canister and snaps into the bracket Computer A laptop will be used for logging data and sending commands to the microcontroller(s) within the containment box. eorgia Institute of Technology 95 of 187

96 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Weights Figure 29 and Figure 30 give a preliminary weight budget for known assemblies and subassemblies. The average density of polycarbonate used in the weight computation is 1200 kg/m 3. Currently, CBE for weight is lb; this is felt to be conservative since the CBE for weight without contingencies is lb a margin of 17.6%. Lighter weight solutions for the containment box and mounting are being developed. eorgia Institute of Technology 96 of 187

97 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 29: Current weight budget with totals, and broken out by known subassemblies. eorgia Institute of Technology 97 of 187

98 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 30: Summary of the weight budget to report subassembly totals Equipment Layout for Take-off, in Flight, and Landing Currently there is no apparatus designed to hold extra canisters to be swapped with the six (6) canisters that begin the flight during take-off in the containment box. However, the general configuration during take-off, flight, and landing for the containment box and internal canisters is the same. This configuration is given in Figure 31. eorgia Institute of Technology 98 of 187

99 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 31: Equipment layout for containment box, 6 canisters, laptop and crew for all stages of flight. The precise placement of operators during parabolas is viewed as non-essential so long as the cabling from containment box to laptop remains intact. Crew may need to change canisters during hypergravity precise configuration for this activity is not currently known. eorgia Institute of Technology 99 of 187

100 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 4.9. Flight Experiment Integration The payload includes all experimental components. A possible configuration for the payload is shown in Figure 32. The assembly is made of four parts: the base bolt, the base, the payload plug, and the payload. eneral dimensions for the payload are listed in Table 27.. Payload Plug Base Bolt Payload Base Figure 32: Payload Assembly Table 27: Payload Assembly Dimensions Parameter Value Base Diameter 4.97 Total Height Payload Height 8.95 Base Thickness 0.1 The experiment is housed in a PVC plastic pipe that is connected to a base. The payload base is designed to be the only load bearing component of the payload assembly. eorgia Institute of Technology 100 of 187

101 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 33: Payload Base with 150N of loading The base rests in the rib of the structure and holds all of the weight of the payload and any sensors used. It is made of Delrin plastic and manufactured using injection molding. The payload base can support roughly 60.85lbs of load before failure. It is designed to support an assumed maximum load of lbs with a factor of safety of 2. This load comes from the assumption that the payload weighs no more than 3lbs accelerated at 10 times the acceleration due to gravity. Figure 33 shows the stress distribution through the base, using SolidWorks SimulationXpress Wizard. eorgia Institute of Technology 101 of 187

102 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 28: Data from SolidWorks SimulationXpress, highlighting the data from assumptions Trial Total Load (lb f ) Max Stress (psi) Factor of Safety eorgia Institute of Technology 102 of 187

103 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 28 shows data taken from SolidWorks SimulationXpress for the payload base. This data was interpolated to find the maximum load of the payload base. Figure 34 shows the factor of safety plotted versus the total load on the payload base. The graph and equation allow the approximate maximum load to be determined mathematically before constructing the first prototypes Factor of Safety vs. Total Load Payload Base (Delrin 2700) Factor of Safety Factor of Safety 5.00 y = x Total Load (lbs) Figure 34: Factor of Safety vs. Total Load from SolidWorks SimulationXpress and generated trend line equation eorgia Institute of Technology 103 of 187

104 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 5. Flight Avionics Feedback is essential to any meaningful design work. In recent years, the have implemented a number of unique launch vehicle designs, each with the intention of finding solutions to particular problems. However, with only limited visual feedback available, it is difficult, if not impossible to gauge the success of a design or to detect any unanticipated failure modes. A system that could accurately describe the state of the rocket throughout its flight would then be enormously valuable. To be effective, such a system would have to be capable of not only recording data from multiple sources but also able to temporally connect the data. This would provide the user insight into the interactions between different factors in addition to the individual measurements. Due to the potential complexity of such a design, the system also needs to be tolerant to the potential failure of any singular functional unit. This would ensure that even if some information is lost, the system will still yield meaningful feedback from tests. Finally, it would be helpful for such a system to be extensible. It is impossible now to envision all of the potential use cases for such a system. Designing it to be easily adapted to the needs of future projects would help ensure its success and longevity Avionics Overview The avionics are designed to accommodate the primary science payload LSIM, in addition to supporting structural and aerodynamic analysis of both the advanced fin design and the rib and stringer fuselage design of the Vespulla MkII. To accomplish this goal, SIDES (Simultaneous Independent Data Logging & Experiment System) was developed to maximize the data extracted from each flight while reducing the risk of failure of a larger avionics system. SIDES architecture allows for a flexible, complex, and fault tolerant distributed data collection system for the launch vehicle. eorgia Institute of Technology 104 of 187

105 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 29: Avionics requirements Requirement Requirement Number Definition 1. The flight avionics shall collect data required for a successful payload experiment. 2. Key elements of the flight systems shall operate on independent power supplies. 3. Power supplies should allow for successful payload operation during launch vehicle flight with up to 1 hour of pad stay and 2 hours of standby time during launch vehicle preparation. 4. The flight avionics shall be capable of being attached to the launch vehicle structure. Source USLI Handbook 1.7 Verification Method Design Feature Status Testing Data logger Complete MSC-3 Testing SIDES nodes Complete MO-4 USLI Handbook 2.11 Testing Testing Battery systems and power management Mechanical Interfaces Complete Complete Verification Source Document eorgia Institute of Technology 105 of 187

106 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Requirement Source Verification Design Status Verification Number Definition Method Feature Source Document 5. PS coordinates of the launch vehicle shall be transmitted to a ground station. USLI Handbook Testing PS, round Station, Xbee Complete 6. Each avionics node shall be capable of data logging with or without a clock pulse. USLI Handbook 2.12 Inspection Flight Software and Data Logger Complete 7. Each avionics node shall operate at some equal or reduced functionality during RS485 communication failure USLI Handbook Inspection Flight Software and Redundant Node Hardware Complete 5.2. Avionics Success Criteria The success of the avionics team will be defined in two ways: minimum success criteria that will be accomplished if the requirements are accomplished, and maximum success criteria that will be met if everything goes according to plan. Maximum success will include collecting diagnostic data for the launch vehicle, such that design feedback is available for iterating the most effective launch vehicle design, while minimum success is limited to successfully collecting and storing the LSIM payload data for recovery and analysis of the data. eorgia Institute of Technology 106 of 187

107 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 30: Avionics Success Criteria Requirement Requirement Definition Source Verification Design Status Verification Numbers Method Feature Source Document 1. The avionics system is Analysis, Complete functional throughout Testing the flight and if failures do occur the entire system does not go down. 2. The ground station Analysis, Complete should be capable of Testing receiving supplementary data transmitted from the launch vehicle. 3. The ground station Analysis, Complete should detect the Testing location of the launch vehicle throughout the flight, and track the location of the landing for recovery purposes SIDES Design Approach SIDES utilizes a distributed network of microcontrollers to accomplish diverse tasks. Each node in the distributed network is capable of operating independently of other nodes. To support this, eorgia Institute of Technology 107 of 187

108 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW each node has a self-contained power supply and data logging capability. This approach reduces risk by preventing the failure of any node from propagating through the SIDES network. Distributed data logging presents a synchronization challenge when compiling distributed data. The integration of the data when clock skew is present becomes much more difficult and often involves resampling and interpolating the data to obtain useful results. By providing a synchronization clock signal, the local data logging rates can be easily adjusted to prevent clock skew. In ideal operating conditions, the individual nodes of the SIDES network will be able to communicate over a bus. For noise immunity, the bus will be a differential pair. To optimize the trade between failure tolerance and weight, electrical harness weight will be reduced by using a one-to-many, multi-drop bus rather than a point-to-point solution. Software control of the multi-drop bus nodes will reduce the risk associated with centralized communication while maintaining the weight advantages of a multi-drop bus SIDESboard The SIDESboard standardizes the nodes, and helps ease implementation of the electronics. The SIDESboard contains all the features necessary at each avionics node to successfully complete the mission. The SIDESboard has a standard harness connector, data logging SD (secure digital) card, battery monitoring circuit, isolated clock input and a standard mechanical footprint. The SIDESboard firmware incorporates a standard set of libraries. These libraries allow programmers to focus on the function of the specific node rather than having Figure 35: SIDES system layout eorgia Institute of Technology 108 of 187

109 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW to code the same functionality each time. The communication bus for the SIDESboard is handled by an RS485 transceiver. The RS485 format is differential for noise rejection, bidirectional to save weight in harness wiring, and multi-drop to reduce wiring complexity while also saving weight. Risk of communication failure is considered to be acceptable for the purposes of saving weight, because the consequences are low-impact by design. Figure 36 and Figure 37 depict the SIDESboard PCB (Printed Circuit Board) design, supporting the features listed above. Figure 36: SIDESboard bottom side view Figure 37: SIDESboard top side view SIDES Electrical Harness eorgia Institute of Technology 109 of 187

110 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The SIDES electrical harness within the Intimidator kit is extremely simple. Only the Telemetry and MasterIMU can be wired together, and as such only require a handful of connections routed between the two standard harness connectors Master IMU The master IMU will house a triple axis accelerometer, gyroscope and magnetometer IMU, and RS485 hardware. In particular, the Master IMU will facilitate sending data of interest to the Telemetry node to be forwarded to the ground station Science Experiment Computer The LSIM payload requires multiple vibration sensors, and will also actuate solenoids used to control the MR fluid during the flight. Due to the switch from Vespulla MkII to the Intimidator kit, integration changes have made connecting the Science Experiment Computer to the SIDES network unreasonably difficult. Therefore, this unit will be equipped with an accelerometer to ensure it can independently determine microgravity timing Telemetry The Telemetry node fulfills the requirement 5 of transmitting the PS data from the launch vehicle to the ground station. The Telemetry node will make use of an Xbee PS transceiver and a SIDEDboard to log the PS data while the Xbee is transmitting the data. An example of the Xbee is depicted in Figure 38. Figure 38: Xbee transceiver unit eorgia Institute of Technology 110 of 187

111 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 5.4. De-scope Options As part of the Flight Systems package for the previous competition cycle, a computer handling telemetry and PS was built and flown. This computer has the capability to run a solenoid driver and read the vibration sensors. Should the SIDES network need to be de-scoped, this substitute hardware already exists and can be inserted into the system design with minor modification. More info on this computer may be found in De-scope Option: Flight Computer Definition Power Budget Table 31 details the power budget for SIDES. Table 31. SIDES Power Budget. eorgia Institute of Technology 111 of 187

112 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 5.6. EM Interference Faraday cages and shielding webbing may be used to mitigate the risk of EM Interference from both the telemetry devices and experiment solenoids. More analysis will be needed to determine the amount of shielding require for example, placement of electrical harness off-axis of the experiment solenoids can negate much of the EMI risk inherent in a magnetics experiment. The precise placement of harness has not been determined as of this point in the launch vehicle development. Redundancy and robustness is key to the SIDES network and any node failures should be survivable further the ground station will provide an added redundancy through more accurate communications should signal strength from the launch vehicle experience dramatic fluctuations Transmission Frequencies and Protocols The telemetry system is designed to utilize two Xbee PRO 900-XSC modules for one-way communication from the launch vehicle to the ground station. Using a simple, loss-tolerant protocol with reliable delivery ensures the data is received if at all possible and that the information is correct. The SIDES node controlling the Xbee module on-board the launch vehicle will utilize a 900MHz monopole-monopole vertically polarized rubber duck antenna with 2 dbi gain and 100mW of power. This antenna s performance is depicted graphically in Figure eorgia Institute of Technology 112 of 187

113 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 39. Receipt of PS data via radio to the ground station will satisfy the recovery requirement and bolster kinematics data of the launch vehicle trajectory. Figure 39: Antenna performance as a function of range 5.8. Software Maturity Flight software for the SIDES nodes has been prototyped and robust implementations are still in development. round station software is in development and the progress achieved thus far is discussed below De-scope Option: Flight Computer Definition The following text is pulled from the 2012 FRR documentation regarding the flight computer, planned as a de-scope option for the SIDES network. Flight Computer The flight computer will be an Arduino Mega which utilizes the ATMEA 2560AU processor. The chip has sufficient I2C, serial, and analog inputs to read data from all sensors and log to an eorgia Institute of Technology 113 of 187

114 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW SD card based on Sparkfun s OpenLog break-out board. Additionally, the chip will run the Fastrax UP501 PS module and send the data to an Xbee PRO for transmission to the ground station. An OpenLog board will provide logging capabilities. The board will be programmed in the Arduino language, a subset of C++ with some additional libraries. Figure 40 provides a generalization of proposed flight computer software. Table 32 lists the major components utilized in this design. Figure 40: eneralization of flight computer software eorgia Institute of Technology 114 of 187

115 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 32: Major Flight Computer Components Part Number Component Picture Description 1 The flight computer microprocessor, the ATmega The PS receiver, the Fastrax UP501 PS module 3 The Xbee PRO 900-XSC module for communication between launch vehicle and ground station 4 The OpenLog board will provide logging capability Avionics Testing and Reliability Assurance Testing was performed on flight systems hardware in order to ensure in-flight success while recording data and transmitting telemetry information. Test cases were written for each major sensor to ensure proper hardware functionality. These test cases will be of significant eorgia Institute of Technology 115 of 187

116 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW value for debugging purposes. This will in turn lead to gains in the longevity of the system as well as in efficiency of programming and future design. This process also led to the creation of a document detailing the current utilization of input and output resources on each of the SIDESBoards. Having this document will ensure that no pins will have overlapping utilization and will facilitate future extensibility by making explicit remaining resources round Station Amateur rocketry is a test bed for novel aerospace designs; however, normal launches provide little feedback beyond basic feasibility. This open loop makes it difficult to refine ideas and identify meaningful or effective designs. While in many cases, acquiring such feedback could be prohibitively expensive, many performance criteria for vehicles can be acquired through relatively cheap means with some effort. Detailed visual observation of a launch vehicle can provide meaningful insight into launch vehicle stability and other important design considerations. Today even cheap digital cameras can provide levels of detail necessary to give meaningful vehicle feedback. Past missions flown by the have encountered interesting performance anomalies and have fallen victim to speculation due to limited data collection and some provocative still camera images. By visually tracking the launch vehicle, unusual flight and structural characteristics can be positively documented and close the design loop by providing feedback for the next design iteration Purpose The ground station is designed to ensure communication with and visual observation of the launch vehicle. Communication quality will be ensured through the use of a high-gain directional antenna. A digital video camera will be used to observe the launch vehicle throughout its flight. The ground station will also feature a detachable PS unit used to make recovery of the launch vehicle easier. eorgia Institute of Technology 116 of 187

117 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Function Both the antenna and camera will be mounted on an alt-azimuthal mount. The mount will have motors enabling automated rotation of the platform in both of its degrees of freedom. The motion of the mount will be controlled by a microcontroller that will also be part of the ground station. In addition to controlling the motors, the controller will also perform the wireless communication that will receive signals from the launch vehicle via the antenna. To effectively accomplish its objectives, the ground station must actively track the launch vehicle throughout its flight. This will be accomplished in one of two ways. The first would use telemetric data received from the launch vehicle to create a model of the vehicle s motion. The second would use a stereo camera system to create disparity maps of the launch vehicle s motion and translate these into a series of distance measurements. This could then be used to create a similar model of motion. The camera zoom will also be adjusted throughout the flight to account for the changing distance between the base station and the launch vehicle and attempt to maintain a near constant level of detail. Table 33: round station requirements Requirement Design Feature Satisfying Requirement Accurately receive High-gain telemetric from launch direction antenna vehicle Requirement Verification Analysis of received signals Success Criteria Sufficient information for modeling motion and retrieving launch vehicle is received eorgia Institute of Technology 117 of 187

118 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Requirement Design Feature Satisfying Requirement Maintain constant visual High optical tracking of launch camera, vehicle motorized mount and control algorithm Provide relative position Detachable PS information of launch module vehicle for recovery Requirement Verification Review of captured video Successfully locate launch vehicle Success Criteria Launch vehicle remains in FOV through apogee Successfully locate launch vehicle eorgia Institute of Technology 118 of 187

119 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Design Considerations Choice of Antenna Figure 41: Diagram of a helical antenna Deciding on the proper type of antenna requires two opposing design characteristics: the directionality and gain of the antenna. Choosing a higher gain antenna will allow for a greater range of operation but would give a smaller beam width. This would increase dependence on the tracking algorithm for ensuring signal quality. A helical antenna offers a good compromise between these two considerations, with typical examples offering a half power beam width of and boresight gains of 8-22 db. This beam width would give some cushion for latency in the tracking algorithm. The gain would also be sufficient to ensure good signal quality even under non-line-of-sight propagation at considerable distance, such as might be the case after landing. Figure 42: Typical radiation pattern for a helical antenna eorgia Institute of Technology 119 of 187

120 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Choice of Camera The choice of video camera posed a similar design decision. Much like an antenna, a camera provides a certain angular window of coverage. For a fixed number of pixels, increasing this window will decrease the detail of the captured images. Unlike an antenna, however, these parameters can be a dynamically changed through the use of zoom. A high optical zoom would then allow for fairly high detail throughout the flight. Camera choice is further complicated by the need to algorithmically adjust the zoom of the camera during flight. While this functionality is built in to most digital cameras, it is seldom available to users programmatically. Models supporting this functionality often do so at prohibitively high costs. Figure 43: Canon Powershot SX260 The Canon Powershot SX260 seems to satisfy all of these requirements. The camera is capable of recording video at 24FPS with an image size of 1920x1080 pixel. The camera also offers and 20x optical zoom. Assuming a 30 vertical field of view or a 60 horizontal field of view, these parameters mean that at its furthest point, each pixel would correspond to 1.7inches of the launch vehicle. This camera also offers access to a user-supported firmware known as the Canon Hack Development Kit which provides direct access to camera operations not offered by factory firmware. This will considerably simplify gaining direct electronic control of zoom Motor Sizing eorgia Institute of Technology 120 of 187

121 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The ability of the platform to track the launch vehicle is inherently limited by the speed and accuracy at which it can rotate. The rotational speed necessary will be dependent on the angular velocity of the launch vehicle from the station s reference frame. Assuming the launch vehicle s path is completely vertical from its Launchpad, the angular velocity of the launch vehicle is given by: dθ dt = xy y 2 + x 2 (6) Where x is the distance from the base station to the launch pad and y is the altitude of the launch vehicle. The maximum angular velocity of the launch vehicle will occur during the burn of the motor, which will occur over the first two seconds of flight. At the end of this acceleration the launch vehicle will be travelling at 177m/s. This design will be used at events where participants will likely use at most class M motors. For this size motor NAR requires a minimum personnel distance of 500 feet5f6, or approximately 150 meters. Assuming this distance for x and constant acceleration over the motor burn yields the following equation: dθ dt = t 1 (7) t s This function takes a value of approximately 0.62radians/s at t=1.4seconds. The motor must then be capable of rotating the mount at a minimum of this speed. Once the moment of inertia for the mounted camera and antenna has been decided, this value can be used to find the required torque for the motor. 6 eorgia Institute of Technology 121 of 187

122 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Software Maturity The software operation of the ground station can be broken into a number of logical components. The process begins by configuring the unit, which consists of initializing contact with the rocket and initializing the state variables for the rocket and ground station. Once this is done, the station will then enter normal operation. This state consists of a loop which processes incoming telemetry information, updating state information for the rocket, deciding whether to update servo position, and deciding whether to update the zoom of the camera. During this process, the station will also characterize the state using two Boolean variables, LAUNCHED and LANDED. Once both of these variables become true, the loop will break, and the station will transmit the resting coordinates of the rocket to the PS Pendant. The figures below show this process and the sub-processes involved in each of these steps. eorgia Institute of Technology 122 of 187

123 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 44: High-Level Software Process eorgia Institute of Technology 123 of 187

124 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 45: Updating Rocket State eorgia Institute of Technology 124 of 187

125 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 46: Updating Servo Position eorgia Institute of Technology 125 of 187

126 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 47: Updating Camera Zoom eorgia Institute of Technology 126 of 187

127 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 48:Transmit Rocket Location Effects of Excess RF Radiation on the Recovery Avionics A simple testing procedure was implemented to ensure the safety of using the e-matches in proximity to the transmitter. An Xbee transmitter operating at 100mW, with an omnidirectional antenna was placed next to an e-match at several points of high transmission power along the antenna and in the near field. The transmitter then sent a variety of packets varying in length from a single byte to the entire ASCII alphabet. At no point during transmission did the e-match ignite. This result was expected given the low output power of the transmitter. eorgia Institute of Technology 127 of 187

128 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Avionics Mechanical Integration The avionics and other electronic systems will be fixed to the rocket through the use of a wooden sled fixed vertically to wooden ribs on the interior of the booster section of the rocket. The circuit boards will be bolted to the sled and their batteries will be zip-tied to the sled. The same method is used to mount the supporting electronics for the scientific payload. eorgia Institute of Technology 128 of 187

129 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 6. eneral Safety 6.1. Vehicle Safety and Environment Overview Ensuring the safety of our members during building, testing and implementation of the payload experiment is an ideal condition. Procedures have been created and implemented in all of our build environments to ensure safety requirements are met and exceeded. A key way the Ramblin' Rocketeers ensure team safety is to always work in teams of at least two when using equipment or during construction. This guarantees that should an incident occur with a device the other member could provide immediate assistance or quickly get addition help if required. The Invention Studio where the team does a majority of its work is equipped with safety glasses, fire extinguishers, first aid kits, and expert personnel in the use of each of the machines in the area. All the members of the payload and flight systems teams have been briefed on the proper procedures and proper handling of machines in the labs. eorgia Institute of Technology 129 of 187

130 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 34: Risk Identification and Mitigation Steps Step Name Hazard Identification Risk and Hazard Assessment Risk Control and Elimination Reviewing Assessments Step Definition The first step is to correctly identify potential hazards that could cause serious injury or death. Hazard identification will be achieved through team safety sessions and brainstorming. Every hazard will undergo extensive analysis to determine how serious the issue is and the best way to approach the issue. After the hazards are identified and assessed a method is produced to avoid the issue. As new information becomes available the assessments will be reviewed and revised as necessary. The steps outlined above in Table 34 are being used to develop a set of standard operating procedures for launch vehicle construction, payload construction, ground testing, and on all launch day safety checklists Mission Assurance The top priority of the Ramblin' Rocketeers is the completion of a safe, successful mission with minimal risk and in-flight anomalies. For this reason, a comprehensive review of all risks associated with the flight of the launch vehicle must be undertaken to gain a fuller understanding what can go wrong from the ground preparation stage to vehicle recovery. Risks associated with the mission may be classified by the probability of occurrence and the severity of a failure. Table 35 provides a risk assessment matrix with color coding for composite risk severity and risk class identification for easy reference at a later time. eorgia Institute of Technology 130 of 187

131 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 35: Risk Assessment Matrix with Risk Class Probability Frequent Likely Occasional Seldom Unlikely Catastrophic I II III IV V Severity Critical VI VII VIII IX X Moderate XI XII XIII XIV XV Negligible XVI XVII XVIII XIX XX Table 36. Launch vehicle failure modes. Failure mode Risk class Cause Mitigation Motor CATO Defective grains Use proper equipment for motor V Improper installation assembly Use instruction manual during assembly Only certified Level 2 HPR fliers should assemble motors Recovery Insufficient black separation powder IV failure Improper venting Improper wiring No PS/data downlink XIX Deficient battery Shorted circuit Rocket out of range eorgia Institute of Technology 131 of 187

132 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 6.2. Payload Safety As already mentioned in eneral Safety, the same methodology to identify and assess risks for vehicle safety will be used to identify hazards for the payload. The entire payload and flight systems teams have been briefed on the possible hazards they may encounter while working with the payload and how to go about avoiding them. Some of these hazards include inhaling small iron powder, ingesting inedible substances, and touching harmful materials. Mitigation steps have been identified for these potential threats. Other hazards that relate specifically to the payload are listed in Table 37. Payload failure modes are outlined in `Table 38. Table 37. Payload hazards and mitigation Hazard Risk Assessment Control & Mitigation Electrocution Serious Injury/death Do not touch wires that are hot and not insulated. Wear rubber gloves when the device is in operation. Handle leads to the power supply with care. Use low voltage settings whenever possible. Electromagnetic Fields Interfere with electronic devices inside the body round test equipment, keep people with electronic components in them away from the coil when the electromagnetic coil is in use. Epoxy/glue Toxic fumes, skin irritation, eye irritation Work in well ventilated areas to prevent a buildup of fumes. loves face masks, and safety glasses will be worn at all times to prevent irritation. Fire Burns, serious injury and death Keep a fire extinguisher in the lab. If an object becomes too hot or starts to burn, cut power and be prepared to use eorgia Institute of Technology 132 of 187

133 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation a fire extinguisher. Soldering Iron Burns, solder splashing into eyes Wear safety glasses to prevent damage to eyes. Do not handle the soldering lead directly only touch handle. Do not directly hold an object being soldered. Drills Serious injury, cuts, punctures, and scrapes Only operate tools under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes Dremel Serious injury, cuts, and scrapes Only operate tools under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes Hand Saws Cuts, serious injury Only use saws under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes. Do not cut in the direction of yourself or others. Exacto Knives Cuts, serious injury, death Only use knives under supervision of team mates. Only use tools in the appropriate manner. Do not cut in the direction of yourself or others. Hammers Bruises, broken bones, Be careful to avoid hitting your hand eorgia Institute of Technology 133 of 187

134 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation and serious injury while using a hammer. Power Supply Electrocution, serious injury and death Only operate power supply under supervision of team mates. Turn of power supply when interacting with circuitry. Batteries Explode Eye irritation, skin irritation, burns Wear safety glasses and gloves. Make sure there are no shorts in the circuit. If a battery gets too hot stop using it an remove any connections to it. Improper Dress during construction Serious injury, broken bones Wear closed toe shoes, clothing that is not baggy, and keep long hair tied back. Exposed construction metal Punctures, scrapes, cuts, or serious injury Put all tools band materials away after use. Neodymium Magnets Pinching, bruising, and snapping through fingers. Do not allow magnets to fly together from a distance, do not play with powerful magnets, keep free magnets away from powered solenoids. Iron Powders Inhaling, skin irritation Wear masks at all time, wear clothing that protects sensitive skin areas. Keep away from oxidizing agents. Mineral Oil Toxic to inhale, ingest, and irritable to skin Label product, wear gloves while working, keep body parts as protected as possible. Oleic Acid Eye irritation, skin irritation, slight hazard for inhaling ang ingesting Wear safety glasses, wear gloves, label product to remove confusion. eorgia Institute of Technology 134 of 187

135 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation Magnetorheological Fluid Dangerous for inhaling, ingesting. Label mixture, keep sealed, keep magnets away unless it is being used for testing. Table 38. Payload safety failure modes Potential Failure Effects of Failure Failure Prevention No power Experiment cannot be performed Check batteries, connections, and switches Data doesn't record No experimental data Ensure power is connected to the payload computer and that all connections are firmly secured Magnetic field interferes with flight computer Accelerometers/ Sensors No experimental data Record erroneous data Shield the flight computer from any EMF interference Calibrate and test accelerometers and all sensors Water/Fluid damages the camera Stop operating, no images, no data Shield the camera from the fluid. Magnetorheologial fluid under an applied magnetic force mixes with water Solenoids Erroneous data. Experiment cannot be performed, wires melt Create different compositions of MR fluid and ensure that MR fluid is sturdy. Check connections, ensure over heating will not occur during testing eorgia Institute of Technology 135 of 187

136 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Potential Failure Effects of Failure Failure Prevention Too much current goes The wires in the Make sure current is only pulsed into the solenoids solenoids get very hot into the solenoids Improper dress during construction Avionics Maiming, cuts, scrapes, serious injury. Chips or boards are manufactured incorrectly causing equipment failures and misfires Do not wear open toed shoes in the build lab. Keep long hair tied back. Do not wear baggy clothing. Test avionics operations, and perform a flight test Personnel and Environmental Hazards As already mentioned in Section 6.1.1, the same methodology to identify and assess risks for vehicle and payload safety will be used to identify hazards for constructing various flight and testing components. A Material Safety Data Sheet (MSDS) is on hand for all materials used in the construction of components, and team members have been briefed on best practices for creating a safe workplace. Table 39 lists possible environmental safety concerns. eorgia Institute of Technology 136 of 187

137 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 39: Environmental Hazards, Risks, and Mitigation Hazard Risk Assessment Control & Mitigation Electrocution Serious Injury/death Do not touch wires that are hot and not insulated. Wear rubber gloves when the device is in operation. Handle leads to the power supply with care. Use low voltage settings whenever possible. Electromagnetic Fields Epoxy/glue Fire Interfere with electronic devices inside the body Toxic fumes, skin irritation, eye irritation Burns, serious injury and death round test equipment, keep people with electronic components in them away from the coil when the electromagnetic coil is in use. Work in well ventilated areas to prevent a buildup of fumes. loves face masks, and safety glasses will be worn at all times to prevent irritation. Keep a fire extinguisher in the lab. If an object becomes too hot or starts to burn, cut power and be prepared to use a fire extinguisher. eorgia Institute of Technology 137 of 187

138 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation Soldering Iron Drills Dremel Burns, solder splashing into eyes Serious injury, cuts, punctures, and scrapes Serious injury, cuts, and scrapes Wear safety glasses to prevent damage to eyes. Do not handle the soldering lead directly only touch handle. Do not directly hold an object being soldered. Only operate tools under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes Only operate tools under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes Hand Saws Cuts, serious injury Only use saws under supervision of team mates. Only use tools in the appropriate manner. Wear safety glasses to prevent debris from entering the eyes. Do not cut in the direction of yourself or others. eorgia Institute of Technology 138 of 187

139 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation Exacto Knives Hammers Power Supply Batteries Explode Improper Dress during construction Exposed construction metal Cuts, serious injury, death Bruises, broken bones, and serious injury Electrocution, serious injury and death Eye irritation, skin irritation, burns Serious injury, broken bones Punctures, scrapes, cuts, or serious injury Only use knives under supervision of team mates. Only use tools in the appropriate manner. Do not cut in the direction of yourself or others. Be careful to avoid hitting your hand while using a hammer. Only operate power supply under supervision of team mates. Turn of power supply when interacting with circuitry. Wear safety glasses and gloves. Make sure there are no shorts in the circuit. If a battery gets too hot stop using it an remove any connections to it. Wear closed toe shoes, clothing that is not baggy, and keep long hair tied back. Put all tools band materials away after use. eorgia Institute of Technology 139 of 187

140 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Hazard Risk Assessment Control & Mitigation Neodymium Magnets RF Interference with the Recovery System Pinching, bruising, and snapping through fingers. Pre-mature firing of the ejection charges potential causing significant damage to the Launch Vehicle, payload, and all supporting systems Do not allow magnets to fly together from a distance, do not play with powerful magnets, keep free magnets away from powered solenoids. RF Testing has verified that, at maximum power output, the onboard XBee transmitter will not unintentionally ignite our e- matches from excess RF radiation. Maximum output power is limited to 100 mw eorgia Institute of Technology 140 of 187

141 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 7. Project Budget 7.1. Funding Overview In order to fund the Competition year, the have sought sponsorships from academic and industry sources. The current sponsors of the Ramblin Rocketeers and their contributions can be found in Table 40. As of CDR, the Ramblin Rocketeers have received $5,700 in funding. Furthermore, the Team has also received a dedicated room in which the Team can construct and store their rocket and non-explosive components. All explosive components (i.e. black power) are properly stored in Fire Lockers in either the Ben T. Zinn Combustion Laboratory or the Center for Space Systems Flight Hardware Laboratory. Table 40. Summary of sponsors for the Ramblin. Rocketeers Sponsor Contribution Date Unused Funds from $1,000 Aug 2012 eorgia Space rant Consortium $2,500 Sept 2012 eorgia Space rant Consortium $500 Sept 2012 eorgia Space rant Consortium $1,000 Dec 2012 eneration Orbit $300 Dec 2012 eorgia Tech $1,000 Feb 2013 Student overnment Association eorgia Tech $2,000 Mar 2013 School of Aerospace Engineering ATK Travel Stipend $400 (est) Apr 2011 ATK Motor Stipend $200 (est) Apr 2011 Total $8,900 The team is currently pursuing the following sponsors: Virgin alactic, eorgia Tech College of Engineering, eorgia Tech SA, as well as private donations. eorgia Institute of Technology 141 of 187

142 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 7.2. Current Sponsors Table 41 lists the current sponsors of the and their contributions. Table 41. List of current sponsors of the Ramblin' Rocketeers. Sponsor eorgia Space rant Consortium Advanced Circuits eneration Orbit Huff Performance eorgia Tech Invention Studio Contribution Financial contribution for general project expenses Financial contribution for Outreach-specific expenses Financial contribution for REFP-related activities. Manufacturing of the SIDES boards throughout the design process Financial contributions for general project expenses. Discounts on motor and motor hardware Professional machines and tooling to fabricate the launch vehicle and payload components 7.3. Actual Project Cost FRR Budget Summary Table 42 illustrates the budget breakdown as of the CDR Milestone. The summary is broken down into four (4) main categories: Launch Vehicle, Flight Systems, Operations, and Motors. The Launch Vehicle and Flight Systems categories are further broken down into two (2) subcategories: Flight Hardware and Testing. Operational expenses are broken down into four (4) sub-categories: Safety, eneric Supplies, Tooling, and Physical Capital. Lastly, while motors are specific to the Launch Vehicle subsystem, they are critical component to the architecture and as such are tracked separately from the Launch Vehicle subsystem. eorgia Institute of Technology 142 of 187

143 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 42. FRR Project Budget Summary. Category Amt Spent Amt Remaining Launch Vehicle $ 1, $ Motors $ $ Flight Systems $ $ Operations $ $ 1, Testing/Dev $ 1, $ System-Level Budget Summary Figure 49 illustrates the system-level expenditure summary for Project LSIM at the FRR milestone. Cost reduction techniques, such as proper resource utilization has resulted in lower Flight Systems costs. It is important to note that both the Launch Vehicle and Flight Systems include both Flight Hardware costs in addition to Test/Development costs. Additionally, Figure 50 illustrates the breakdown. System Expenditure Breakdown Launch Vehicle $ Flight Systems $ Operations $ Motors $ Testing/Development $ 1, Outreach $ Total $ 3, Figure 49. System expenditure summary at CDR. eorgia Institute of Technology 143 of 187

144 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Sub-system Testing/Development Breakdown Aerodynamics $ Structures $ Recovery $ 0.00 Avionics $ Payload/round $ Testing round Station $ 0.00 Total $ 1, Figure 50. Sub-system Testing/Development Breakdown Flight Hardware Expenditures Flight Hardware Expenditure Overview Figure 51 summarizes the overall expenditures for all Flight Hardware purchased up to the CDR milestone. In order to account for uncertainties in motor price, $300 has been allotted for the purchase of the flight motor. As illustrated by Figure 51, only hardware for the Aerodynamics and Mechanical Integration sub-systems has been purchased. eorgia Institute of Technology 144 of 187

145 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Sub-system Flight Hardware Breakdown Aerodynamics $ Structures $ Recovery $ Motors/Motor Hardware $ Mechanical Integration $ Electrical Integration $ 0.00 Flight Avionics $ Flight Payload $ Total $ 1, Figure 51. Sub-System Flight Hardware Breakdown Flight Hardware Cost Breakdown Figure 52 lists the flight hardware breakout for Flight Systems. It is important to note that the materials purchased for the Launch Vehicle flight hardware has not been used to fabricate any parts, therefore no breakout is available at this time for the launch vehicle. eorgia Institute of Technology 145 of 187

146 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Flight Experiment Item Description Unit Price Qty Cost L.S.I.M. Hardware $ $ Propellant Simulant (Water) $ $ Diameter PVC Pipe $ $ Balance Solenoids $ $ Camera Assembly $ $ Piezo Vibration Sensor $ $ 5.90 Base Plate $ $ 1.00 Payload Bottom $ $48.00 Total Flight Experiment Costs $ Flight Avionics Item Description Unit Price Qty Cost SIDES Network $ $ SIDES Board $ $ Electrical Harness $ $ ClockDrive Board $ $ LSIM Board $ $ Telemetry Board $ $ MasterIMU $ $ Strain age Board $ $ SIDES Node Battery $ $ LSIM Battery $ $ Total Flight Avionics Cost $ Figure 52. Flight Systems flight hardware breakout. eorgia Institute of Technology 146 of 187

147 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 8. Project Schedule 8.1.Schedule Overview The Mile High Yellow Jacket s project is driven by the design milestone s set forth by the USLI Program Office. The design milestones are listed in Table 43. The project antt Chart for Project L.S.I.M. located in Appendix I contains only high-level activities due to the unique launch vehicle and payload designs. A more detailed Critical Path chart is located in Section 8.2. Table 43. Design milestones set by the USLI Program Office. Milestone Proposal Team Selection Web Presence Established PDR Documentation PDR VTC CDR Documentation CDR VTC FRR Documentation FRR VTC Rocket Week PLAR Documentation Date 26 SEP 17 OCT 4 NOV 28 NOV 6 DEC 23 JAN 2 FEB 26 MAR 2-11 APR APR 7 MAY eorgia Institute of Technology 147 of 187

148 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 8.2. Critical Path Chart: CDR to PLAR The critical path chart illustrated by Figure 6 demonstrates the highly integrated nature of Project L.S.I.M. The critical path chart identifies: High Risk Tasks Low-Moderate Risk Tasks Earned Value Management (EVM) oal Tasks Looping Tasks Critical and Alternate Paths Major Inputs to Tasks eorgia Institute of Technology 148 of 187

149 eorgia Tech Flight Readiness Review Figure 53. Critical Path Chart from CDR to PLAR

150 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 8.3.Schedule Risk High Risk Items Two (2) items have been identified as High Risk Items. These are: Launch Vehicle Structure Design Recovery System Design Table 44 lists the mitigations for these items. Table 44. Identification and Mitigations for High-Risk Tasks. High-Risk Task Potential Impact on Project L.S.I.M. Mitigation 1) Ensure personnel have direct and free access to experienced personnel on and off of the team. Launch Vehicle Design, Fabrication, & Testing 1) Schedule Impact 2) Budgetary Impact 3) Not qualifying for Competition Launch 2) Ensure personnel have knowledge on to effectively utilize simulation and analysis tools. 3) Ensure personnel have direct and free access to the simulation and analysis tools. Recovery System Design, Fabrication, & Testing 1) Excessive kinetic energy during landing resulting in damage to the rocket. 2) Failure to deploy the drogue and/or main parachute resulting in a high energy impact with the ground destroying the Launch Vehicle. 4) Ensure personnel are familiar with relevant fabrication techniques. 1) Ensure Recovery System Lead has direct and free access to experienced personnel on and off the team. 2) Provide real-time feedback of the design decisions to ensure all recovery-related requirements are meet with at least a 5% margin wherever possible. 3) Ensure proper manufacturing techniques are utilized during the fabrication of the recovery system. eorgia Institute of Technology 150 of 187

151 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW High-Risk Task Potential Impact on Verification of Field Equations & Control Logic Project L.S.I.M. 1) Unsuccessful flight demonstration 2) Flight Experiment does not function properly during flight 3) Flight Experiment encounters a flight anomaly that results in excessive draw and damage to the Flight Avionics, Power Supply, and/or Launch Vehicle Mitigation 1) Develop multiple paths to achieve the end goal of developing thee robust control logic that is required for the successful demonstration of the Flight Experiment. 2) Ensure Flight Systems personnel have direct and free access to experienced personnel on and off of the team. 4) Ensure personnel have direct and free access to the simulation and analysis tools necessary for the development (and subsequent verification) of the control logic Low-to-Moderate Risk Tasks The low-to-moderate risk tasks are considered to be those risks that pose a risk to either the project schedule and/or project budget but little to no risk of not meeting the Mission Success Criteria in Table 5. The risks and mitigations are provided in Table 45. eorgia Institute of Technology 151 of 187

152 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Table 45. Low to Moderate Risk items and mitigiations. Risk Risk Level Potential Impact on Fabrication of Launch Vehicle Sections Full-Scale Launch Vehicle Test Flight Flight Computer Fabrication round Testing & Control Logic Development Moderate Moderate Low Moderate Project A.P.E.S. 1) Schedule Impact 2) Budgetary Impact 3) Not qualifying for Competition Launch 1) Schedule Impact 2) Budgetary Impact 3) Not qualifying for Competition Launch 1) Budgetary Impact 2) Not able to collect inflight data 1) Schedule Impact 2) No Experimental Flight Data is recorded prior to the Competition Launch. Mitigation 1) Ensure Manufacturing and Fabrication Orders (MFO s) are sufficiently detailed for the task prior to starting any fabrication. 2) Ensure proper manufacturing techniques are observed during fabrication. 1) Ensure Launch Procedures are established practiced prior to any launch opportunity. 2) Have a sufficient number of launch opportunities that are in different geographical areas as to minimize the effects of weather on the number of launch opportunities. 1) Ensure proper manufacturing techniques are observed during fabrication. 2) Ensure Manufacturing and Fabrication Orders (MFO s) are sufficiently detailed for the task. 3) Descope custom board to COTS hardware 1) Ensure personnel have direct and free access to experienced personnel on and off of the team. eorgia Institute of Technology 152 of 187

153 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 9. Educational Engagement Plan and Status 9.1. Overview The goal of eorgia Tech s outreach program is to promote interest in the Science, Technology, Engineering, and Mathematics (STEM) fields. The intend to conduct various outreach programs targeting middle school students and educators. The Ramblin Rocketeers will also have an outreach request form on their webpage for educators to request presentations or hands-on activities for their classroom Atlanta Makers Faire had a booth at the Atlanta Makers Fair, a fair in which various craftsman from the community and eorgia Tech assemble to show off their accomplishments. The intent of this program is to give clubs, organizations, and other hobbyists the opportunity to show others their unique creations and skills. The event is open to the entire Atlanta Figure 54. Participation at the Atlanta Makers' Faire. community and had a large attendance this year. The booth had a display of our various rockets, as well as a station for children to make their own paper rockets. Our booth had middle school aged children attend and participate in the paper-rocket activity FIRST Lego League and Tech Challenge FIRST is a series of international robotics competitions for students from 3 rd -12 th grades. FIRST Lego League is an engineering competition designed for middle school children in which eorgia Institute of Technology 153 of 187 Figure 55: Previous FIRST Lego League outreach event.

154 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW they build and compete with an autonomous MINDSTORMS robot. Every year there is a new competition centered on a theme exploring a real-world problem. FIRST Tech Challenge is a robotics competition designed for students in middle and high school where the robots can be 18x18x18 inches at the start of each match. This year the have had an educational booth at a FIRST Lego League Regional Competition at Wheeler High School which occurred on Saturday, December 8 th.at the booth students ranging from 3 rd -8 th grade were exposed to how lift is generated and participated in building a paper rocket with a straw launcher that they could take with them. The event reached 373 students, 295 of which were in the 4 th -9 th grade range, and 31 educators. Below in Figure 56 and Figure 57 are pictures from this event. Figure 56: FLL Regional Event at Wheel High School eorgia Institute of Technology 154 of 187

155 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 57: FLL Regional Straw Rocket Activity In addition to the FIRST Lego League Regional at Wheeler High School, the Ramblin Rocketeers are scheduled to have a booth at both the FIRST Tech Challenge Regional at Wheeler Middle School on Saturday, January 19 th and the FLL State Tournament at eorgia Tech on Saturday, January 26 th. eorgia Institute of Technology 155 of 187

156 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW References Simon, T. M., Reitich, F., Jolly, M. R., Ito, K., & Banks, H. T. (1998). Estimation of the E ective Permeability in Magnetorheological Fluids. CRSC Technical Report CRSC-TR98-35, NC State Univ. The Dynamic Behavior of Liquids in Moving Containers: with applications to space vehicle technology. All articles. Ed. H. Norman Abramson. NASA, Washington, D.C., "Apogee Paramagnetic Oxygen as Experimental Electromagnetic Separator: Preliminary Design Review." Comp. eorgia Tech University Student Launch Initiative. Atlanta: Print. Cheng, David. Field and Wave Electromagnetics. 1st ed. Reading, MA: Addison-Wesley Publishing Company, Print. Niskanen, Sampo. OpenRocket vehicle Technical Documentation. 18 July Web. Apke, Ted. "Black Powder Usage." (2009). Print. < PerfecFlite. StratoLogger SL100 Users Manual. Andover, NH: Print. < Roensch, S. (2010). "Finite Element Analysis: Introduction." 2011, from Fiberglass Epoxy Laminate Sheet. MATWEB.com. search/datasheet_print.aspx?matguid=8337b2d050d44da1b8a9a5e61b0d5f85 "Shape Effects on Drag." NASA Web. 19 Nov < 12/airplane/shaped.html>. Cavcar, Mustafa. "Compressibility Effects on Airfoil Aerodynamics." (2005). Print. eorgia Institute of Technology 156 of 187

157 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix I: antt Chart eorgia Institute of Technology 157 of 187

158 ID Task Name Duration Start Finish Predecessors 1 Project L.S.I.M. 225 days Wed 8/1/12 Thu 6/6/13 2 RFP Released by NASA 30 days Wed 8/1/12 Tue 9/11/12 3 Proposal 22 days Wed 8/1/12 Fri 8/31/12 Aug '12 Sep '12 Oct '12 Nov '12 Dec '12 Jan '13 Feb '13 Mar '13 Apr '13 May '13 J Project L.S.I.M. RFP Released by NASA Proposal 4 Team Formation 5 days Mon 8/20/12 Fri 8/24/12 5 Initial Rocket Design 20 days Wed 8/1/12 Tue 8/28/12 6 Flight Experiment Definition 20 days Wed 8/1/12 Tue 8/28/12 7 Internal Proposal Review 0 days Tue 8/28/12 Tue 8/28/ Proposal Submitted 0 days Fri 8/31/12 Fri 8/31/12 9 8/28 Proposal Submitted 8/31 10 Prelimary Design Review 71 days Fri 8/31/12 Thu 12/6/12 Prelimary Design Review 11 Launch Vehicle 31 days Fri 8/31/12 Sat 10/13/12 16 Flight Systems 31 days Fri 8/31/12 Fri 10/12/12 23 Project Level 71 days Fri 8/31/12 Thu 12/6/12 30 PDR Documentation Submitted 0 days Mon 10/29/12 Mon 10/29/12 31 PDR Documentation Submitted 10/29 32 Critical Design Review 68 days Sat 10/13/12 Mon 1/14/13 Critical Design Review 33 Launch Vehicle 57 days Mon 10/29/12 Mon 1/14/13 34 Recovery Detailed Design 51 days Mon 10/29/12 Mon 1/7/ Structure Hardware Testing 19 days Mon 10/29/12 Thu 11/22/12 14,30 40 Full-Scale Launch Vehicle Fabrication 38 days Fri 11/23/12 Mon 1/14/ Recovery round Testing 1 day Sat 1/12/13 Sat 1/12/ Stability Analysis 51 days Mon 10/29/12 Mon 1/7/ CFD of Launch Vehicle & Fin Can 20 days Mon 10/29/12 Fri 11/23/ Development of stability model 40 days Mon 10/29/12 Fri 12/21/ Verification of Scaled Test Launch 11 days Mon 12/24/12 Mon 1/7/13 46,47 49 Flight Systems 67 days Sat 10/13/12 Sat 1/12/13 50 Control System Preliminary Design 56 days Mon 10/29/12 Sat 1/12/ Detailed Experiment Modeling 36 days Sat 10/13/12 Fri 11/30/ round Testing 31 days Sat 10/13/12 Fri 11/23/ Flight Systems Integration Plan 36 days Mon 10/29/12 Mon 12/17/ Initial round Station Development 35 days Mon 10/29/12 Fri 12/14/ Project Level 56 days Mon 10/29/12 Mon 1/14/13 56 Website Updates 56 days Mon 10/29/12 Sat 1/12/ Outreach Events 56 days Mon 10/29/12 Sat 1/12/ Completed 1st Draft of CDR 5 days Mon 12/17/12 Fri 12/21/12 59 Completed 2nd Draft of CDR 8 days Tue 1/1/13 Thu 1/10/ Final editing of CDR Package 2 days Fri 1/11/13 Sat 1/12/ CDR Documentation Submitted 0 days Mon 1/14/13 Mon 1/14/13 62 CDR Documentation Submitted 1/14 63 Flight Readiness Review 46 days Mon 1/14/13 Mon 3/18/13 Flight Readiness Review 64 Rocket 36 days Mon 1/14/13 Mon 3/4/13 65 Launch Vehicle Final Assembly 15 days Mon 1/14/13 Fri 2/1/ Full-Scale Test Flight(s) 21 days Mon 2/4/13 Mon 3/4/ Flight Systems 46 days Mon 1/14/13 Mon 3/18/13 68 Experiment Refinement 30 days Mon 1/14/13 Fri 2/22/ Control System Refinement 46 days Mon 1/14/13 Mon 3/18/ Integration of Flight Experiment & Avionics 15 days Mon 1/14/13 Fri 2/1/ Project Level 46 days Mon 1/14/13 Mon 3/18/13 72 Website Updates 46 days Mon 1/14/13 Mon 3/18/ Outreach Events 46 days Mon 1/14/13 Mon 3/18/ FRR Documentation Submitted 0 days Mon 3/18/13 Mon 3/18/13 75 FRR Documentation Submitted 3/18 76 Rocket Week 34 days Thu 3/7/13 Mon 4/22/13 77 Fabrication of Flight Experiment 20 days Tue 3/19/13 Mon 4/15/13 68,69 Rocket Week 4/22 78 Competition Launch Preparation 28 days Thu 3/7/13 Mon 4/15/ Arrive in Huntsville 1 day Wed 4/17/13 Wed 4/17/13 80 Tour of MSFC 1 day Thu 4/18/13 Thu 4/18/13 81 Rocket Fair 1 day Fri 4/19/13 Fri 4/19/13 82 Competition Launch 2 days Sat 4/20/13 Mon 4/22/ Post-Launch Assument Review Submitted 24 days Mon 5/6/13 Thu 6/6/13 82 Post-Launch Project: USLI natt Chart Date: Mon 3/18/13 Task Split Progress Milestone Summary Project Summary External Tasks External Milestone Deadline Page 1

159 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix II: Launch Checklist Pre-Launch Packing The night before launch go through Launch Vehicle Packing List and put all items in a designated spot. The morning of launch go through Launch Vehicle Packing List and ensure all items are still there. Load the vehicle(s) Performer Inspector Launch Avionics On Prepare Payload Bay Ensure batteries and switches are wired to the altimeters correctly. Ensure batteries, power supply, switch, data recorder and pressure sensors are wired correctly. Install fresh batteries into battery holders and secure with tape. Test the altimeters. Altimeter In Circuit Out of Circuit Altimeter 1 Altimeter 2 Insert altimeter and payload into the payload bay. Connect appropriate wires. Verify payload powers on correctly and is working properly. If it is not, check all wires and connections. Turn off payload power. Arm altimeters with output shorted to verify jumper settings. This is to check battery voltage and continuity. Disarm altimeter, un-short outputs. eorgia Institute of Technology 159 of 187

160 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Assemble Charges Test e-match resistance and make sure it is within spec. Remove protective cover from e-matches. Measure amount of black powder determined in testing. Put e-matches on tape with sticky side up. E-match Resistance E-match 1 E-match 2 E-match 3 E-match 4 Pour black powder over e-matches. Seal tape. Re-test e-matches. Check Altimeters Ensure altimeter is disarmed. Connect charges to altimeter bay. Turn on altimeter and verify continuity. Disarm altimeters. Altimeter 1 Altimeter 2 OFF ON Pack Parachutes eorgia Institute of Technology 160 of 187

161 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Connect drogue shock cord (long side) to booster section and altimeter bay (short side) Fold excess shock cord so it does not tangle. Add Nomex cloth to ensure only the Kevlar shock chord is exposed to ejection charge. Insert altimeter bay into drogue section and secure with shear pins. Pack main chute. Attach main shock cord to payload bay (long side to nose cone). Fold excess shock cord so it does not tangle. Add Nomex cloth under main chute and shock cord ensuring that only the Kevlar part of the shock cord will be exposed to the ejection charge Connect shock cord to nose cone, install nose cone and secure with shear pins. eorgia Institute of Technology 161 of 187

162 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Assemble Motor Follow manufacturer's instructions. Put on safety glasses and gloves. Do not get grease on propellant or delay. Do not install igniter until at pad. Install gasket on top of motor. Install motor in launch vehicle. Secure positive motor retention. Final Prep Turn on payload via a switch and start stopwatches. Install skin. Inspect launch vehicle. Check C to make sure it is in safe range; add nose weight if necessary. Bring launch vehicle to the range safety officer (RSO) table for inspection. Bring launch vehicle to pad, install on pad, verify that it can move freely (use a standoff if necessary). Arm altimeters via switches and wait for continuity check for both. Install igniter Touch igniter clips together to make sure they will not fire igniter when connected. Make sure clips are not shorted to each other or blast deflector. Return to front line. Launch Stop the stopwatches and record time from arming payload and launch. Watch flight so launch vehicle does not get lost. Post Launch Recovery Recover launch vehicle, document landing. Disarm altimeter(s) if there are unfired charges. Disassemble launch vehicle, clean motor case, other parts, inspect for damage. Record altimeter data. Download payload data. eorgia Institute of Technology 162 of 187

163 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Trouble Shooting Test Problem Control & Mitigation Power on payload Payload does not Check batteries have sufficient charge, check wires power on are connected correctly E-match resistance Check E-match does not match resistance required specifications Replace e-match before use Power on altimeters Altimeters do not Check batteries have sufficient charge, check wires power on are connected correctly Check for altimeter continuity after No continuity Check wires are connected correctly installing e-matches Launch Rocket Engine does not fire Disconnect power, ensure igniter clips are not touching, ensure power is reaching clips,ensure motor is assembled correctly eorgia Institute of Technology 163 of 187

164 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix III: Science Overview Ferromagnetism and MR fluid response Scientific Background and Mathematical Modeling To the end of accomplishing the goals of the LSIM experiment, some theoretical research and work must be accomplished in tandem with experimentation. A passive or active control system is to be developed in order to move the simulated propellant to its desired location with the magnetorheological (MR) fluid. To model the behavior of the simulant-mr fluid system, equations are being researched, modified, and developed in order to calculate magnetic fields and forces, to govern the properties of MR fluids, and to model system dynamics. In addition to equations, qualitative research has been done in the literature concerning MR fluids to suggest approaches that may be taken during experimental testing. Magnetic fields The forces on the MR fluid that will be transmitted to the simulant will depend largely on the magnetic fields that are applied to the fluid. Control of currents in a solenoid will allow for precise control of the fields. Last year, it was derived and also confirmed in the literature that the exact magnetic H field from a current loop in spherical coordinates, with the loop centered at the origin in the xy -plane and counterclockwise current, is as below (θ denotes azimuth angle): H r = CR2 cos θ α 2 E(k 2 ) β C H θ = 2α 2 β sin θ [(r2 + R 2 cos 2θ)E(k 2 ) α 2 K(k 2 )] where K and E are complete elliptic integrals of the first and second kinds, respectively, and α 2 = R 2 + r 2 2Rr sin θ, β 2 = R 2 + r 2 + 2Rr sin θ, k 2 = 1 α 2 β 2, and C = I π. I is the loop current, R is its radius, and r is the distance from the origin to the point of measurement. A solenoid simply consists of several such current loops, with the fields adding vectorally. While the above expressions are extremely nonlinear and difficult to analyze or work with, they may be simplified as needed, or modeled using a computer. eorgia Institute of Technology 164 of 187

165 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Magnetic forces After calculating the magnetic fields, in order to predict the motion of the MR fluid and simulant in the container, the forces on the MR fluid due to the field must to be calculated. In any material, the movement of atomic charges such as electrons causes the atoms to behave as microscopic magnetic dipoles, experiencing forces in magnetic fields. The magnetization vector M at a point in the material is defined as the volume density of magnetic dipole moment, i.e. m k M = lim v 0 v Each m k is the magnetic moment of the k th atom in volume v, and the sum is over all atoms. M depends on the magnetic field H at a point, and flux density B depends on the field, as follows: M = χ m H B = μ 0 (H + M) = μ 0 H(1 + χ m ) = μ 0 μ r H = μh where χ m is the material s magnetic susceptibility, μ r is its relative permeability, and μ is the absolute permeability. It is assumed that χ m, and hence μ and μ r, are approximately constant for the MR fluid. This is a very valid assumption that greatly simplifies analysis, given that the fields are not extremely large, as is evidenced in Figure 58 below taken from a paper by Simon et al. Figure 58: Plot of B field magnitude in MR fluid versus magnitude of vector μ 0 H, for iron volume concentrations of 10, 20, and 30 percent eorgia Institute of Technology 165 of 187

166 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The force on a magnetic material can be determined by summing the forces on the dipoles in the material due to the field that it is placed in. The force on a magnetic dipole m in field B is F = (m B) Let V be the volume of a very small region of the MR fluid in which M is approximately constant. Then, letting m = MV = χ m VH = χ mv B, the force on the region is µ F = χ mv µ B B = 2χ mv B (B) µ Using equations (1), (2), and (5) for the H and B fields of a current loop, it can be seen that the force on each small region, and hence on the whole fluid, should be directly proportional to the square of the current. In addition, B (B) may be calculated using equations (1) and (2). These equations will be further developed to better understand response of the MR fluid and simulant. MR fluid rheological properties In addition to translational movement, which is governed by the preceding equations, MR fluids experience large increases in yield strength in the presence of magnetic fields. This is desirable for the LSIM system, as otherwise the sloshing propellant simulant would simply shear through the MR fluid barriers with little resistance. It is desired to characterize the rheological properties of MR fluid to understand how much resistance to movement the simulant will experience. More precisely, MR can be modeled fairly closely as a Bingham plastic, a common example of which is toothpaste. A Bingham plastic does not start flowing until a certain point of yield shear stress, after which it behaves similarly to a viscous liquid. The equation governing the shear stress of an ideal Bingham plastic, and so to model the MR fluid for future analysis, is τ = τ yield (H) + η dv dn for τ > τ yield(h) τ yield (H) is the yield shear stress of the MR fluid, and is larger for stronger H fields. η is the flow viscosity after shear, and dv is the velocity gradient in the direction normal to the plane of dn shear. This relation is shown on the next page in Figure 59, compared to a Newtonian fluid. eorgia Institute of Technology 166 of 187

167 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 59: Shear stress of ideal Bingham plastic (and MR fluid model) versus shear rate dv, compared to ideal dn Newtonian liquid Hence, if the simulant exerts such a force that MR fluid flow begins occurring, the shear stress between layers of the MR fluid should increase, keeping the simulant comparatively restrained until it settles again. If the need arises to decrease the yield shear stress for a given magnetic field, such as to make the MR fluid flow more easily, replacing a percentage of microscale ferroparticles with nanoscale particles can decrease the yield stress. Further research is still required to find the relationship between the yield strength and magnetic field, which will allow control of the yield stress acting against the simulant. However, the key observation is that there is little to no MR fluid flow below some certain shear stress, for a given magnetic field H. System Dynamics While research on the physical properties and behavior of MR fluids is ongoing, basic system dynamical modeling has already been started with variable parameters that will be determined from theory and experimentation in the future. The fluid and MR fluid mixture is assumed to operate roughly as a system with a spring, damper, and mass, where the driving force is the solenoid. The fluid is considered the mass, whose motion is restrained by a spring and damper, and driven by the MR fluid actuated by the solenoid. All system elements lie on the same x - axis, with the solenoid axis coinciding. The dynamical equation of motion in this case is eorgia Institute of Technology 167 of 187

168 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW mx = F solenoid kx bx Where m is the mass of the fluid, k and b are unknown damping placeholder constants, and x is the position of the simulant relative to some point. After some manipulation, the dynamical equation for the response of the fluid becomes: eorgia Institute of Technology 168 of 187

169 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Understanding Slosh Damping Fluid dynamics and hydrodynamic regimes of expected slosh In considering the liquid slosh, the flight regime of the vehicle is extremely important. While the experiment aims to approximate a spacecraft by manipulating MR fluid during microgravity to dampen water slosh, the realities of atmospheric flight will limit the applicability of launch vehicle test results. The extent of these flight regime limitations is revealed by three key similarity parameters: the Weber (We) number, the Froude (Fr) number, and the Bond (Bo) number. These three parameters measure the ratio of inertial to capillary forces, the effect of gravitational body forces relative to inertial forces, and the relative magnitudes of gravitational and capillary forces respectively. Finally, an understanding of the potential flow of sloshing fluid is necessary to understand the motion of fluid inside a vehicle. Flight regime However, an estimate of the flight regime of the launch vehicle near apogee must first be known. To better understand this flight regime and to confirm the microgravity requirements pulled from previous team documents, a first-order analysis of the launch vehicle s flight was computed. Neglecting drag and assuming 2-D projectile motion with instantaneous acceleration from a rocket motor, the flight profile of the launch vehicle was estimated and the characteristics of the 0.1-ee requirement from the 2009 eorgia Tech team 0.1-ee being the definition of the microgravity threshold for the purposes of the experiment were examined. The results of this simplified analysis are presented graphically in Figure 60. eorgia Institute of Technology 169 of 187

170 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 60: Microgravity time as a function of launch angle from horizon In Figure 60, the microgravity time, or t micro, was computed using equation (8). t micro = V 0sin (α) (8) g In equation (8), the 1.5 s addition represents the time from apogee to chute deployment, which by representation in Figure 60 is always less than the other half of the equation for launch angles between 60 and 90 degrees. The drogue chute deployment therefore represents the bounding time for the experiment operation in the mission profile. From the flight profile, a velocity corresponding to 0.1-ee and a maximum height can be calculated. These variables can be used for the computation of similarity parameters, as well as comparison numbers to judge the validity of the flight profile and microgravity estimates. Two comparison measures will now be observed. Among the simplest environments for creating microgravity is the free-fall drop test. This test provides microgravity times approximated by equation (9) valid to heights of 20 m with atmospheric drag. Equation (9) is nonspecific with regards to the accelerations achieved, however these are estimated by Reynolds and Satterlee (p. 435, Dynamic Behavior) to be between 10 7 and 0.2. eorgia Institute of Technology 170 of 187

171 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW t micro = h (9) The predicted times from equation (9) and from the flight profile are given in Figure 60. Table 46: Microgravity times for fall heights Height (m) Microgravity time (s) (free-fall) (free-fall, target altitude) (90 launch angle) ~7.13 Adjusting for the 1.5 second chute deployment, the 90 launch microgravity time appears to be about one half the time given for free-fall from the same maximum height given that the max ee loading specified in the reference is 0.2, or twice the requirement, this difference appears to be acceptable for a bounding and ideal case. Of course, accelerations due to aerodynamic forces will requirement additional modeling and adjustment. Similarity parameters Table 47 presents the similarity parameters relevant to the LSIM experiment calculated for the propellant simulant, water (30 C). The Weber, Bond, and Froude numbers are considered here. These numbers provide an indication of the hydrodynamic regime these regimes eorgia Institute of Technology 171 of 187

172 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW 7 Figure 61: Slosh regimes and similarity parameters6f for microgravity are illustrated in Figure 61. The Reynold s number is also included for comparison; although for this experiment the number itself is not as significant as long as the regime described by different test configurations is similar, i.e. all turbulent, all laminar, etc. A potential source of error in these computations is use of the launch vehicle velocity rather than the relative velocity of the fluid in the tank. The Weber, Froude, and Reynold s numbers are affected by this choice, which is yet to be validated. Table 47: Similarity parameters for simplified flight profile of the launch vehicle Number Equation Value Bo ρgl 2 /σ 980 We ρu 2 L/σ 1.37x10 7 Fr We/Bo 1.4x10 4 Re ρul/μ 2.023x10 7 These parameters will allow verification and comparison of ground tests with the launch vehicle test and REFP, vis-à-vis actual spacecraft and launch vehicles. 7 Reynolds, William C. and Hugh M. Satterlee. Liquid Propellant Behavior at Low and Zero. The Dynamic Behavior of Liquids p Ref Appendix XXX eorgia Institute of Technology 172 of 187

173 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Modeling Slosh In order to approximately predict the behavior of the propellant in the sloshing modes expected at apogee of our launch vehicle, a mathematical model has been developed. The aim of this model is solely to predict sloshing behavior in the absence of dampening; this is an intermediate step to modeling the effects of the MR fluid dampening. Predicting the exact distribution and dynamics of all sloshing fluid within the container, however, would require a large amount of complexity, which would only be exacerbated by attempting to add the effects of the MR fluid later on. Therefore, for analysis to be feasible, a much simpler model is proposed. Figure 62. Schematic and free-body diagram of slosh dynamic model The fluid is modeled schematically as shown above in Figure 62. It is assumed that the center of mass of the fluid in the tank behaves roughly as an object of mass m attached to a pendulumspring of spring constant k, with additional dampening effects represented by viscous dampers of constants b 1 and b 2. Also, let L be the original length of the pendulum-spring with no forces applied, and L the the amount the spring is stretched from length L (so that negative L implies compression). It is anticipated that the majority of sloshing will be longitudinal, so significant vertical motion can be expected of the fluid. Therefore, in our model, the spring may experience appreciable compression. However, a much smaller amount of lateral sloshing is predicted, so in the model, the angle θ may be assumed to be small. Therefore, throughout this analysis, it will be assumed that sin θ θ sufficiently closely for the corresponding substitution to be justified. eorgia Institute of Technology 173 of 187

174 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The equations of motion can be written in the x and y directions, respectively, as follows: k L sin θ b 1 x k Lθ b 1 x = mx (1) k L cos θ b 2 y mg k L b 2 y mg = my (2) The equations to be developed will depend on state variables θ, θ, L, and L. Let the origin of the coordinate system be at the center of rotation of the pendulum. Then, it is known that x = (L + L) sin θ (L + L)θ (3) y = (L + L) cos θ (L + L) (4) x = L θ + (L + L)θ (5) y = L (6) x = L θ + 2 L θ + (L + L)θ (7) y = L (8) where equations 5 through 8 are found by repeatedly differentiating equations 3 and 4. First of all, substituting equations 6 and 8 into equation 2 and rearranging, it is readily found that L = g b 2 m ΔL k m L (9) Note that this equation is independent of θ, and is the same as a one-dimensional spring-massdamper system. The analysis and results from substituting equations 5 and 7 into equation 1 are significantly more complicated. First of all, carrying out this substitution and rearranging, θ = k L b 1 L m(l + L) Next, substituting equation 9 for L in equation 10, it is found that θ = (b 2 b 1 ) L m(l + L) L (L + L) θ b 1 m + 2 L (L + L) θ (10) g (L + L) θ b 1 m + 2 L (L + L) θ (11) Therefore, as k, b 1, b 2, m, g, and L are constants, it is seen that θ is a function of the state variables. Write θ = f θ, θ, ΔL, ΔL, where f: R 4 R is differentiable at any point eorgia Institute of Technology 174 of 187

175 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW θ, θ, ΔL, ΔL such that L -L, due to continuity of the partial derivatives of f at those points. The relation L = -L only occurs for the spring being compressed into a flat piece, which corresponds to all fluid molecules touching the top surface of the tank; both of these are impossible scenarios. Therefore, it is possible to linearly approximate f close to any point of interest, for easier analysis. Initially, the relation is linearized for points near the equilibrium point of the system, which is (0, 0, mg/k, 0). In this case, defining δl = ΔL mg/k, θ = f θ, θ, ΔL, ΔL θ = 0 + f θ eq f 0,0, mg mg, 0 + f 0,0, k k, 0 θ, θ, δl, ΔL (12) θ + f θ + f θ eq ΔL δl + f ΔL (13) eq ΔL eq Finally, evaluating the partial derivatives, it is found that close to (0, 0, mg/k, 0), gk θ = (kl + mg) θ b 1 m θ (14) Therefore, relations for both L and θ have been found only in terms of the four state variables θ, θ, ΔL, and ΔL, assuming that the values of θ, θ, δl, and ΔL are small. Using the above equations, whether the linear approximations (9) and (14) or the more precise but complicated form (11), further analysis by hand or by computer should yield information as to how the system should approximately behave in the absence of the MR fluid baffles. Further development should also approximate system dynamics in the presence of the baffles, allowing rough predictions to be made as to how the MR fluid baffles may impact fluid slosh. Unifying the LSIM theories Finally, it is necessary to connect the response of MR fluid to a magnetic field with the damping of slosh. According to Dynamic Behavior the damping of slosh for a ring baffle is dependent on the baffle cross-section7f8. For containers of constant geometry and liquid at constant rest height in gravity dominated slosh, empirical relationships have been illustrated between the geometry of 8 Abramson, H. Norman and Sandor Silverman. Damping of Liquid Motions and Lateral Sloshing. The Dynamic Behavior of Liquids p Ref Appendix XXX. eorgia Institute of Technology 175 of 187

176 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW a rigid baffle and the damping ratio vs. wave amplitude of slosh8f9. However, an effect not present in the dynamic analysis above is the container geometry. In the case of LSIM where the liquid height will be greater than the container radius, the damping coefficient in lateral slosh is given by: δ = 4.98ν 1/2 R 3/4 g 1/4 (1) Where ν is the kinematic viscosity, R the container radius, g the acceleration of gravity. This equation9f10, along with curve fitting with the help of tables and plots given in Dynamic Behavior, provides a means to experimentally determine the damping coefficients needed with given MR fluid response to calculate the slosh dynamics. 9 P P. 110 eorgia Institute of Technology 176 of 187

177 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix IV: round Test Plan oals The LSIM ground test data will provide the basis for empirical modeling of magnetorheological fluid as a damper for liquid sloshing. All actions will be incremented to allow for a detailed model for extrapolation and interpolation of the data for future flight control systems. round Test oal round Test oal Definition 1 Create MR Fluid 2 Calibrate Sensors 3 Determine force of MR Fluid 4 Develop model for solenoid control 5 1- slosh dampening Test Sequence 1 - Creating MR Fluid MR fluid will be created using different compositions of iron powder, mineral oil, and surfactant. The iron powder will make up about 74-76% of the mixture's mass. Mineral oil will make up 20-22% of the total mass, and the surfactant will make up the remaining 1-4%. Water is then added to test the time to mixture separation and solenoids. Each mixture will be preliminarily tested by neodymium magnets. The mixture will qualify as a successful batch if MR fluid under the influence of an applied magnetic field prevents the leakage of water. Test Sequence 2 - Characterize the shear stress of MR fluid In characterizing MR fluid, the team will utilize a two-plate test for measuring the MR fluid's force and viscosity with and without a magnetic field acting upon the MR fluid. This test was chosen because of its simplicity; other tests such as a barometer test were considered for measuring the MR fluid's viscosity and force, but they turned out too complicated to realize. eorgia Institute of Technology 177 of 187

178 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW The two-plate test consists of two plates: a bottom plate, which is fixed to the ground and a top plate, which is free to move. A load sensor will be placed on the top plate to measure the reaction force that is generated. The plates used must not be strongly magnetic; thus, the two current choices are wood or aluminum. A control test will be performed by just having two plates together with a load sensor on the top, moving plate to calculate the force by the plates themselves. For accurate and consistent results, an automated pulling device will be used to pull the top plate. Once a control has been measured, MR fluid will be placed between the two plates and the same procedure will repeat with and without the MR fluid under a magnetic field. These tests will characterize the force that MR fluid will generate when it is under a magnetic field and when it is free of a magnetic field Test Sequence 4 - Developing solenoid control Knowing the MR fluid shear stress properties will help determine the size and strength of the solenoid used for flight testing. This will also enable the group to decide on what type of control can be used on the solenoid. At the moment, an open loop control is considered. If better coupling can be achieved between sensors and actuators, closed loop control may be considered. Test Sequence 5 1- Slosh dampening A vibration rig will be constructed such that several frequencies of vibration approximating those experienced by the launch vehicle will be exerted on the ground test rig. Using similarity parameters, the data gained from this experiment will allow predictions for dampening performance of the controlled MR fluid during the microgravity period. eorgia Institute of Technology 178 of 187

179 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Appendix V: Science MFOs and Drawings Bench Stand Take one 1/16 12 x 12 acrylic plate and laser cut out a square that is 20cm x 20cm. Figure 63. Base Plate eorgia Institute of Technology 179 of 187

180 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Take the remaining two 12 x 12 plates and cut a rectangle that is 20cm x 22cm. Laser cut a 5.3cm diameter centered in the middle of the 20cm x 22cm acrylic plates as seen in Figure 2. Figure 64. Second and Top Plate eorgia Institute of Technology 180 of 187

181 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Take four 30cm Maker Bars and place them vertically 20 cm apart in the shape of a square. Attach horizontally a 20cm Maker Bar 2 cm above each 30cm Maker Bar base and secure them with 90 Degree Maker L Brackets as shown in Figure 3 and 4. This will be done on each side of the square. Figure 3 shows a side view of two 30 cm Maker Bars attached together by a 20cm Maker Bar horizontally. eorgia Institute of Technology 181 of 187

182 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Figure 65. Side view of main structure Figure 66. Trimetric view of main structure eorgia Institute of Technology 182 of 187

183 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Attach four flat L Maker Beam brackets on the 20 cm horizontal bars as show in in Figure 5. The short end of the L bracket will be placed 1cm from the end of the 20cm Maker Bar. This will hold the 20cm x 20cm solid acrylic base plate in place. Figure 67. Top view of structure with 90 Degree L Brackets eorgia Institute of Technology 183 of 187

184 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW On each vertical 30cm Maker Bar, attach the base of a 90 degree bracket 2 cm above the 20cm horizontal Maker Bar (5cm from the bottom of the vertical 30cm Maker Bar) as shown in Figure 6. Do this for each vertical 30 cm Maker Bar facing inward into the square. These four 90 degree brackets will hold the second acrylic plate. Figure 68. Side view of 90 Degree Brackets eorgia Institute of Technology 184 of 187

185 EORIA TECH RAMBLIN ROCKETEERS FLIHT READINESS REVIEW Four cm above the top of each 90 degree bracket (9cm from the bottom of the vertical 30cm Maker Bar), place the base of another 90 degree bracket as shown in Figure 6. These four 90 degree brackets will hold the third acrylic plate. Place the 20cm x 20cm acrylic base plate that has no hole cut in it over the four, flat L Maker Beam brackets. The place the other two 20cm x 22cm acrylic plates that have holes in them on the 90 degree brackets creating three layers of acrylic plates as shown in Figure 7. Figure 69. Test Structure with Base Plates Place the 100 ml beaker through the acrylic plates and onto the base acrylic plate. eorgia Institute of Technology 185 of 187