Space Transportation Network Analysis for Cis- Lunar Space Economy with Lunar Resources

Transcription

1 Space Transportation Network Analysis for Cis- Lunar Space Economy with Lunar Resources Koki Ho, Assistant Professor Hao Chen, PhD candidate Space Systems Optimization Laboratory University of Illinois at Urbana-Champaign 1

2 Background Space Logistics: The theory and practice of driving space system design for operability and managing the flows of materiel, services, and information needed throughout the system lifecycle (AIAA Space Logistics Committee) Campaign-level strategic logistics paradigm is required Logistics network becomes increasingly complex for future space exploration Combination of Prepositioning, Carryalong, and/or Resupply? Spacecraft design for multiple different missions Effective use of logistics infrastructure such as In-situ Resource Utilization (ISRU) and propellant depot. Credit: AIAA [1] In-Situ Resource Utilization (ISRU) [2] Propellant depot [3] Oil field in space Gas station on orbit 2

3 Research Objective Our Capability: A campaign-level architecture/design optimization tool Optimize multiple missions and their technology uses concurrently Capture trades for multiple technology options ISRU (lunar, Martian), Propulsion (chemical, NTR, SEP), in-space manufacturing, etc Applicable for various destinations: LEO, GEO, Moon, Mars, NEO, etc This presentation will show a scenario for human lunar exploration w/ lunar resources Research Objective To develop an integrated dynamic campaign-level space mission optimization framework to evaluate the impact of lunar resources in human lunar exploration. Architecture optimization embedded for fair evaluation of the value of ISRU. Emphasis on both ISRU deployment and its utilization. 3

4 Problem modeling (Credit: ULA [4, 5] ) 4

5 Generalized Multi-Commodity Flow (GMCNF) Space logistics modeling by Time-Expanded Generalized Multi-Commodity Flow (GMCNF) (Ishimatsu [6], Ho [7, 8] et al.) Generalized multi-commodity flow: Multi-commodity network with arcs that involve gain/loss, commodity type conversion, or both of them. E.g. ISRU propellant generation E.g. Propellant consumption E.g. Food->Waste Origin Destination Commodity: [payload, vehicle, propellant, food, water, waste, structure, crew, ] Intermediate Node Self-loops: Resource generation/consumption at nodes 5

6 Time-Expanded GMCNF Formulation [9] + x ijt x ijt (i, t) (j, t + Δt ij ) Minimize: Subject to: + x vijt + y vijt J = t {0 T 1} + (c T + (v,i,j) A vijt x vijt 0 T : Time steps (integers) W ij : Time windows for Arc (i, j) ± : Commodity in/outflow x ijt + c + vijt s v y + vijt ) (v,j):(v,i,j) A v,j : v,j,i A x vji t tij d it t 0 T 1 i N (v,j):(v,i,j) A v,j : v,j,i A y vji t tij d ivt t 0 T 1 i N Q vij ± x vijt ± x vijt + x vijt + = x vijt t {0 T 1} (v, i, j) A s v y vijt s v y vijt + + H vij x vijt e v y vijt t {0 T 1} (v, i, j) A 0 p 1 if t W ij = 0 p 1 otherwise t {0 T 1} (v, i, j) A s v = F(e v, f v ) v V Mass balance Flow Transformation Flow Concurrency Flow bound Spacecraft design model 6

7 Outline Introduction Problem Settings and Assumptions Human Space Mission 7

8 Cis-Lunar Transportation Mission Assumptions ACES spacecraft Parameter Assumed value ACES propellant capacity 68,040 [kg][4, 10] ACES structure mass 5,917 [kg][4, 10, 11] ACES Propellant type LOX/LH2 [4, 10] Propellant I sp 420 [s][4, 10] Propellant Propellant tank LO2 mass capacity 57,538.5 [kg] (Credit: ULA [4, 5] ) Propellant tank LH2 mass capacity 10,461.5 [kg] Propellant tank Propellant tank structure mass 4,000 [kg] Vulcan rocket tank capacity 1 [5] Vulcan Water ISRU system 5 [kg water/ year/ kg system] Water electrolysis mass ratio oxygen : hydrogen = 8:1 ISRU system ISRU maintenance spare 5% [system mass] Vulcan rocket structure [5] 8

9 Cost Model Parameter Assumed value Launch cost $5,000/kg [4, 5] LO2 on Earth $0.09/kg [12] LH2 on Earth $5.94/kg [12] ACES operation cost per flight $1M [12] ISRU development cost $10,000/kg [5] ISRU operation cost $600/kg-year [5] ACES manufacturing cost $149M Propellant tank cost $20M Cislunar-1000 Unmanned Space Vehicle Cost Model, version 8 (USCM8) [13] USCM8: Recurring manufacturing cost of the first flight unit in FY2010 Thousands of Dollars Y = X Vehicle structure mass Estimates for ACES: Y = $142.36M 89% $149M USCM8 Discount for multivehicle manufacture Inflation $ 9

10 Outline Introduction Problem Settings and Assumptions Human Space Mission 10

11 Cis-Lunar Human Space Mission (Credit: ULA [4, 5] ) Human Mission Demand and Supply Payload Type Crew cabin & equipment Crew cabin & equipment Time Node [days] Go to the Moon Supply [kg] Earth ,000 Moon ,000 Return to Earth Crew cabin Moon ,000 Crew cabin Earth 360-5,000 ISRU, Propellant, Tanks, Water, Food Earth All time + Human space mission context A 120-day lunar mission with 5 astronauts every year. Size of crew cabin is estimated based on Apollo mission spacecraft 11

12 Cis-Lunar Human Mission (Earth resourced) No ISRU used. 12

13 Cis-Lunar Human Mission (campaign-level: 3 year) ISRU system provides propellant for ACES flight, especially for the return trip. 13

14 Human Mission Cost Comparison (w/ vehicle reusability) Economic Impact of ISRU 14

15 Contributions and Conclusions Research Objective To develop an integrated dynamic campaign-level space mission optimization framework to evaluate the impact of lunar resources in human space exploration. A campaign-level architecture/design optimization tool Optimize multiple missions and their technology uses concurrently Capture trades for multiple technology options (e.g., ISRU, propulsion, in-space manufacturing ) Computationally efficient techniques with Mixed-integer linear programming (MILP) method Proposed optimization framework can be used to Simulate and optimize long-term space exploration campaign to various destinations (e.g., LEO, GEO, Moon, Mars, NEO ) Evaluate the potential economic benefits of space logistics infrastructure and spacecraft Identify the potential areas for commercialization in space exploration, and optimize the space mission architecture for commercialization. 15

16 Reference [1] Space Logistics Technical Committee, URL: [retrieved 31 May 2017]. [2] Schreiner, S. S., "Molten Regolith Electrolysis Reactor Modeling and Optimization of In-Situ Resource Utilization Systems," M.S. Thesis, Massachusetts Institute of Technology, [3] Kutter, B. F., Zegler, F., O Neil, G., and Pitchford, B., A Practical, Affordable Cryogenic Propellant Depot Based on ULA s Flight Experience, AIAA SPACE 2008 Conference and Exposition, AIAA , San Diego, CA, Sep [4] Bernard F. Kutter, Cislunar-1000: Transportation Supporting a Self-Sustaining Space Economy, ULA, AIAA Space [5] Transportation Enabling a Robust Cislunar Space Economy, ULA, Space Resources Roundtable, Planetary & Terrestrial Mining Sciences Symposium June [6] Ishimatsu, T., de Weck, O.L., Hoffman, J.A., Ohkami, Y., and Shishko, R., Generalized Multicommodity Network Flow Model for the Earth-Moon-Mars Logistics System, Journal of Spacecraft and Rockets, Vol. 53, No. 1, 2016, pp [7] K. Ho, O. de Weck, J. Hoffman, and R. Shishko, Dynamic Modeling and Optimization for Space Logistics Using Time- Expanded Networks, Acta Astronautica, Vol. 105, No. 2, pp , [8] K. Ho, O. de Weck, J. Hoffman, and R. Shishko, Campaign-Level Dynamic Network Modelling for Spaceflight Logistics for the Flexible Path Concept, Acta Astronautica, Vol. 123, pp , [9] H. Chen and K. Ho, Integrated Space Logistics Mission Planning and Spacecraft Design with Mixed-Integer Nonlinear Programming, AIAA SPACE 2016 Conference and Exposition, AIAA , Long Beach, CA, Sep [10] Jonathan Barr, ACES Stage Concept: Higher Performance, New Capabilities, at a Lower Recurring Cost, ULA, AIAA Space [11] Bernard F. Kutter, et al., Atlas Centaur Extensibility to Long-Duration In-Space Applications, AIAA [12] Transportation Architecture for Cislunar Space, ULA, Space Solar Power [13] Wertz, J., Everett, D., Puschell, J. Space Mission Engineering: The New SMAD, Microcosm Press, Hawthorne, CA, 16 USA, 2011.