Design Project/484 Planning

Transcription

1 Design Project/484 Planning Lecture #26 December 6, 2012 Current status of design architecture strawman Spring 2013 Organization David L. Akin - All rights reserved Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

2 Optimizing a Modular Extensible Architecture for Low-Cost Human Exploration of the Moon, Near-Earth Objects, and Mars David L. Akin AIAA Paper Space 2012 Conference

3 Prior Publications in this Study AIAA Paper , SpaceOps 2010 Demonstrated technical feasibility of modular approach for human lunar exploration AIAA Paper , Space 2010 Examined probabilistic risk estimates for multimodule lunar landing vehicles AIAA Paper , Space 2011 Investigated application of modular architectures to near-earth objects and missions to Mars orbit Incorporated cryogenic propellants and Falcon Heavy 3

4 Fundamental Axioms/Assumptions Focus on human space exploration - leave ISS resupply to commercial sources Start without new technologies (e.g., no cryogens, no propellant transfer, no new launch vehicles) All launches on Falcon Heavy (at least initially) Hard budget cap of $3B/year for exploration Single human spacecraft (no LM equivalents) Start human missions as soon as feasible; continue throughout future development cycles Emphasize a variety of destinations and everincreasing capabilities 4

5 Small Crew Vehicle Scaling Exercise Uses methodology from NASA investigation of Orion scaling from Apollo Spacecraft diameter of 3.57 m Apollo 3.9 m Orion/MPCV 5 m Listed data is for 4-person crew 3-person crew used for Moon NEO and Mars require auxiliary (possibly inflatable) habitats 5

6 GTO-LLO Lunar CONOPS 6

7 LEO-LLO Lunar Architecture CONOPS 7

8 LEO-LEO Lunar Architecture CONOPS 8

9 Lunar Component Masses and Costs LEO-LEO LEO-LLO GTO-LLO 9

10 Cargo Capacity to Lunar Surface 10

11 Notes on Lunar Design Cases Residual payload to LLO and lunar surface are driven by packing factor of launch vehicles LEO-LEO case is close to optimum for 4 FH case LEO-LLO delivers the most residual payload (increasing mission flexibility) but requires extra FH Spacecraft sizing is driven by lunar ascent requirements of GTO-LLO case GTO-LLO advantages in earlier studies was due to LOX/LH2 upper stage on launch vehicles LEO-LEO at severe disadvantage in direct payload delivered to lunar surface 11

12 Cost for 10 Lunar Missions (85% LC) 12

13 Lunar Costs at 4x FH Launch Costs 13

14 Discussion of Lunar Program Elements Total nonrecurring costs $3.6B-$4.8B can easily fit within a $3B/year cap with a 7-year development cycle No nonrecurring costs due to launch vehicles Smaller vehicles across the program Average costs $1.0B-$1.1B per mission Minimum cost (especially minimum nonrecurring costs) favor GTO-LLO architecture Suggest paying a premium to go with LEO-LLO to get higher margins and auxiliary payloads 14

15 Near-Earth Object Missions Two missions each to 2007XB m/sec 2001QJ m/sec Assume 53,000 kg OPM and LEO staging Storables LOX/LH2 Delivered payload is basic spacecraft (4795 kg) and at least 10,000 kg of support/science hardware Spacecraft nonrecurring paid under lunar program 15

16 Additional Payload to 2007XB23 16

17 Additional Payload to 2001QJ142 17

18 NEO Program Costs 18

19 NEO Costs at 4x Launch Costs 19

20 Discussion of NEO Program Elements Near-Earth objects are less difficult in mission operations than lunar, other than duration No strong incentive to develop LOX/LH2 OPMs for NEOs Nonrecurring cost advantage to storables Total mission cost advantage to storables except for higher-energy destination at 4x launch surcharge Average costs $1.58M-$1.75M per mission ΔVs to Mars orbits (Phobos/1000 km) only m/sec higher than 2001QJ142 20

21 Mars Orbit-Surface Infrastructure Aerodynamic deceleration (15% of gross mass) Supersonic parachute (2% of gross mass) 650 m/sec powered landing 5625 m/sec ascent to orbit Considered both storable and cryogenic (LOX/ LH2) propellants 10,000 kg of surface systems payload Total payload delivered to low Mars orbit Storable systems: 106,000 kg Cryogenic systems: 72,130 kg 21

22 Mars Orbit-Surface Systems (Storables) 22

23 Mars Orbit-Surface Systems (LOX/LH2) 23

24 Heavy-Lift Launch Vehicle Analysis Assume three stage, LOX/LH2 throughout Each HLLV design optimized to minimize total cost parameter (nonrecurring plus 10 production units) LEO payload ranged from 70 MT 200 MT Cost estimation based on NASA SVLCM algorithm Program costs for HLLV include amortization of nonrecurring costs 24

25 NASA SVLCM HLLV Cost Estimates 25

26 Required Launches per Mars Mission 26

27 Mars 5-Mission Costs (Surface Cryo) 27

28 Mars 5-Mission Costs (Surface Storables) 28

29 Discussion of Mars Program Elements Development of exploration -based HLLV triples cost of the program Falcon Heavy $3.1B-$3.9B/mission HLLV $8.2B-$11.9B/mission 80% of HLLV mission costs are launch-related Significant advantage (~30% cost savings) to using LOX/LH2 for both Mars OPMs and Mars surface architecture Further savings available as Mars program does not have to develop spacecraft, orbital support assets, OPM (if also used for NEOs) 29

30 Conclusions Use of simple existing technologies provides early, affordable, repeatable human access to the lunar surface, NEOs, and Mars surface Within the assumed program elements (1-2 lunar missions/year, 4 NEO missions, Mars every cycle) there is no economic justification for HLLV Primary technology needs are lightweight human spacecraft compatible with surface ops, long-term cryogenics storage This architecture enables two human lunar missions/year and either NEO missions or human Mars missions every 26-month launch window 30

31 Future Work Better graphics! Detailed design of vehicles (crew module, propulsion modules, long-duration habitats) Perform reliability analyses for NEO and Mars cases Consider additional advanced technologies (e.g., in-situ propellants, aerobraking, reusability) for future missions Add cost factors for launch site infrastructure development Perform detailed scheduling to get launch-by-launch, year-by-year program outlay Incorporate discount rate on outlays Analogue tests of human elements (e.g., spacecraft habitability, surface operations) 31

32 Goals of ENAE 483/484 (and 788D) Learn the basic tools and techniques of systems analysis and space vehicle design Understand the open-ended and iterative nature of the design process Simulate the cooperative group engineering environment of the aerospace profession Develop experience and skill sets for working in teams Perform and document professional-quality systems design of focused space mission concepts 32 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

33 Matrix Organization The project team is divided into six specialty groups Systems Integration (SI) Mission Planning and Analysis (MPA) Loads, Structures, and Mechanisms (LSM) Power, Propulsion, and Thermal (PPT) Crew Systems (CS) Avionics and Software (AVS) You will be assigned to a specialty group - but you do get to express your preferences 33 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

34 Systems Integration Overall coordination of design activities Creation and tracking of budgets, particularly mass and cost Maintenance of canonical system configuration documents Vehicle- and system-level trade studies Cost estimation Tracking of vehicle center of gravity and inertia matrix Advanced technology (e.g., robotics) 34 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

35 Mission Planning and Analysis Creation and maintenance of design reference mission(s) (DRM) Orbital mechanics and launch/entry trajectories Determination of operational mission objectives Concept of operations (CONOPS) Programmatic planning (sequence of missions) Science instrument/payload definition 35 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

36 Loads, Structures, and Mechanisms Identification and estimation of loads sources Structural design and analysis Selection of structural shapes and materials Stress modeling Deformation estimation Design optimization Design of mechanisms (docking/berthing ports, separation mechanisms, launch holddowns, engine gimbals)) Tracking of critical margins of safety 36 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

37 Power, Propulsion, and Thermal Electrical power generation Energy storage Power management and conditioning Primary propulsion (orbital maneuvering) Reaction control system (rotation/translation) Design of propellant storage and feed systems Thermal modeling and analysis Thermal control systems Power budgets 37 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

38 Crew Systems Internal layout Emergency egress systems Lighting and acoustics Window and viewing analysis Life support systems Air revitalization Water collection and regeneration Cabin thermal conrol Waste management Food and hygiene EVA accommodations 38 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

39 Avionics and Software Data management (flight computers) Networking Sensors Power distribution Guidance system Control systems, including attitude control Communications Robot control systems Software Data transmission budgets 39 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

40 Near-Term Assignments Go to the Blackboard site and take the test for your opinions on 484 group assignments Also fill out the survey on your peer reviews of team members you have worked with this term Your assessment should include both the individual s technical contributions and their merits as a team member Rate them neither agree nor disagree if you worked with them and are ambivalent; rate no opinion if you didn t work with them You will not receive a grade in this class until both of these are done! 40 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

41 Closing Comments Focus on numerical analysis and systems engineering this is not hardware-bashing Look for your own design solutions this is also not catalog shopping Approach everything rigorously with numbers this is also not adjective engineering Manage scope and risk along with cost, mass, and other design parameters Be innovative, while remaining real What you get out of the process is directly proportional to what you put in 41 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design

42 A Few End-of-Term Modifications The Avionics/Simulation group design project is due on Tuesday, with an automatic extension to Friday, 12/14 if you need it The final exam will be a take-home exam, handed out on Tuesday 12/11 and due on Tuesday, 12/18 Anything covered in class is fair game The scope of the exam would be appropriate for a (challenging) in-class exam: it should only take a few hours It s still a final exam! No collaboration, help from others, etc. 42 Design Project/484 Planning ENAE 483/788D - Principles of Space Systems Design