Critical Design Review University of Illinois at Urbana-Champaign NASA Student Launch 2016-2017 Illinois Space Society 1
Overview Illinois Space Society 2
Launch Vehicle Summary Illinois Space Society 3
Flight Profile Illinois Space Society 4
Current Launch Vehicle Design Lower Separation Stage 3) Main deploy at 700 1) Separation at Apogee Upper Separation Stage 1) Separation at Apogee 2) Drogue Deploy 2s after apogee 2) Bundled Payload Parachute deployed 2s after apogee 3) Full Deployment at 900 Illinois Space Society 5
Vehicle Major Dimensions Overall Length: 120 Overall Estimated Mass: 35.9 lb Main Body OD: 6.188 Nose Cone Length: 24 Booster System Length: 48 Avionics Coupler Tube Length: 14 Payload Coupler Tube Length: 15 Illinois Space Society 6
Mass Statement Mass estimate of subscale was within 5% Total mass predicted with component breakdown Small margin added and generous estimate made Mass Breakdown: +Booster Tube: 18.7 lbs. +Avionics Coupler: 6.9 lbs. +Payload : 5.7 lbs. +Upper Section: 4.3 lbs. Total: 35.9 lbs. Illinois Space Society 7
Current CP Location: 90.83 in Current CG Location: 78.26 in Stability Margin (at liftoff): 2.03 calibers Static Stability Margin Illinois Space Society 8
Motor Subsystem Motor: AeroTech L1390G-P Motor Diameter: 75 mm Liftoff Thrust: 312.8 lbf Total Impulse: 887.2 lbf s Burn time: 2.6 sec Liftoff T/W: 8.71 Off Rail Speed: 64.7 ft/s RMS 75/3840 Casing Fiberglass Centering Rings Aeropack Retainer Illinois Space Society 9
Booster Subsystem Houses motor subsystem Fiberglass fins Slotted between centering rings 1515 Rail buttons (2) Houses drogue parachute Illinois Space Society 10
Avionics Coupler Section U-Bolt connections for strength ¼ Threaded rods to hold payload sleds Holds recovery electronics and ejection charges Two rotary switches Contains main parachute Deployed bundled at apogee Illinois Space Society 11
Avionics Bay Recovery Hardware Parachutes Main: Iris Ultra 96 Drogue: Fruity Chutes Elliptical 18 Black powder ejection charges Ignited by e-matches ½ Tubular Kevlar shock cord Redundant altimeters 1 Telemetrum altimeter for altitude and tracking 1 Stratologger altimeter for altitude Will be official competition altimeter Redundant Jolly Logic Chute Releases for main Illinois Space Society 12
Payload Bay Payload electronics Payload section recovery electronics Mechanical landing system 3 Switchband Viewing holes for cameras 4 Rotary switches Illinois Space Society 13
Payload Bay Recovery Hardware Parachutes Payload: Skyangle Model C2: 44 Held closed by redundant Jolly Logic Chute Releases until 900 ft AGL Black powder ejection charges ignited by e-matches ½ Tubular Kevlar shock cord Redundant altimeters 1 Telemetrum altimeter for altitude and tracking 1 Stratologger altimeter for altitude Illinois Space Society 14
Vehicle Verification Plan Full verification plan found in CDR Report Key verification milestones Aerodynamics verified via subscale flight Refinement of simulations Incremental testing on a component and vehicle level Full vehicle models verified during test flight Illinois Space Society 15
Subscale Vehicle ~42% scale model of flight vehicle Similar materials and stability margin Similar motor characteristics Practice construction techniques Illinois Space Society 16
Subscale Flight Results Subscale was launched on December 10 th at a rocket launch held by Central Illinois Aerospace at Dodds Park, located in Champaign. The ascent went smoothly, the payload section took photos, and the parachute deployed at the right moment However, the shock cord detached from the lower section due to a failure in the adhesive bond during ejection Illinois Space Society 17
Subscale Results vs. Expectations Lower than expected apogee. Second subscale to explore possibilities. Descent differences due to disconnect. Illinois Space Society 18
Flight Profile Apogee: 5344 ft. Max Velocity: 689 ft s Max Mach Number:.61 Max Acceleration: 307 ft s 2 Illinois Space Society 19
Terminal Velocities Booster+Avionics Coupler Drogue: 81.4 ft/s Main: 12.6 ft/s Payload+Nosecone Bundled Main: 89.1 ft/s Deployed Main: 20.7 ft/s Kinetic Energies Avionics Coupler: 15.3 ft lbf Booster Tube: 36.3 ft lbf Payload (Camera+Landing System): 38.1 ft lbf Nosecone + Upper Airframe: 28.6 ft lbf Kinetic Energy All kinetic energies are significantly lower than the competition requirement of 75 ft lbf Illinois Space Society 20
Drift Predictions All values calculated in Open Rocket Analysis redone with 5 degree launch angle into wind All calculated drift distances meet the competition requirement. Section 0 mph winds 5 mph winds 10 mph winds 15 mph winds 20 mph winds Upper Payload Section Drift [ft] 990 1385 1780 2240 2550 Lower Booster Section Drift [ft] 1050 1425 1805 2310 2610 Illinois Space Society 21
Flutter Analysis Used AeroFinSim to determine if the thickness of the fins is structurally sufficient. Takes aerodynamic drag, lifting forces, and fin geometry into account and calculates critical velocities where flutter effects occur 1/8 in fins were chosen for PDR in order to minimize weight of the rocket. Flutter Analysis determined that 3/16 in fins are necessary. Illinois Space Society 22
Test Plans and Procedures Dimensions and weights to be verified on arrival of components Components and hardware inspected for quality and manually load tested Electronics and connections tested and inspected Parachute pull test Full scale test flight Illinois Space Society 23
Staged Recovery System Testing Ejection charges and parachutes loaded in the same manner as on launch day Ballast mass used to replace fragile components Remote deploy: wire E-match remote firing system Planned to start immediately upon completion of construction Shear pins determined by actual weight and predicted accelerations Electronic testing: power lifetime, functionality, and interference Illinois Space Society 24
Landing Hazard Detection and Vertical Landing Payload Illinois Space Society 25
Payload Requirements Identification and differentiation of three 40 x40 tarps Real time data processing Custom software package using open source libraries Upright landing Landing of rocket section housing camera Landing in launch orientation Internal requirements 90 minutes life for electronics 6 or smaller diameter rocket 3 lb or less total weight (body tube weight not included) Lander Section Illinois Space Society 26
Payload Overview Two Subteams Mechanical Landing Subsystem Image Processing Subsystem Illinois Space Society 27
Mechanical Landing Subsystem Overview Spring-loaded deployable landing legs Fold within body tube, deploy automatically upon ejection 1. Stored within body tube 2. Deployment begins upon ejection 3. Fully deployed during descent Illinois Space Society 28
Landing Subsystem Dimensions and Materials 12 total leg length, two 6 segments 3D printed PLA legs used for prototyping COTS springs and fasteners 3/8 Aircraft plywood bulkhead Illinois Space Society 29
Robustness of Landing System Four leg system chosen over three legs Tip over analysis performed to determine failure tolerance Future testing for validation Illinois Space Society 30
Landing System Testing to Date Prototype legs completed and tested for strength Lower bulkhead/leg assembly created Second iteration with updated leg design in progress Illinois Space Society 31
Landing System Future Work Survivability drop tests On variety of surfaces from pre-calculated heights Tip-over tests Parachute drop tests Full scale flight test Illinois Space Society 32
Image Processing Overview Illinois Space Society 33
Image Processing Subsystem Hardware Raspberry Pi Zero processor Camera Module V2 1080p capable 48 x 62 degree FOV COTS pressure sensor Li-ion battery 3.7 V to 5 V converter Rotary switches Illinois Space Society 34
Electrical Schematic Illinois Space Society 35
Raspbian Jessie Lite OS Image Processing Subsystem Software SimpleCV implemented for image processing functions Illinois Space Society 36
Image Processing Progress to Date Hardware components obtained Tarp size identification analysis performed Illinois Space Society 37
Subscale Test Flight Raspberry Pi, camera, converter, and battery flown on test flight Power system design validated Image capture and saving capability proven in flight Illinois Space Society 38
Subscale Lessons Learned Additional work on camera settings required Decreased blurring necessary Color consistency improvements required Sled layout critical, many connection constraints Illinois Space Society 39
Image Processing Future Work Camera setting tuning required Full-scale sled integration tests Implementation and testing of blob detection algorithms Detection testing using given tarp samples Ground tests Drop tests Flight tests Illinois Space Society 40
Questions? Illinois Space Society 41