SSPARC Using architecture Models to Understand Policy Impacts ncreas cost B-TOS Policy increases Swarm of small sats.3 launch probability doing observation Utility for mu of success Probability of Success From Weigel, 2002 SSPARC Using architecture Models to Consider uncertaint Tech Sat Constellation of satellites doing observation of moving objects on the grou Uncertainties driven by instrument performance/cost
15 Space Systems, Policy, and Architecture Research Consortium ©2002 Massachusetts Institute of Technology 29 Using Architecture Models to Understand Policy Impacts B-TOS Case Study: Probability of Success Impact of 1994 U.S. Space Transportation Policy for a Minimum Cost Decision Maker 0.98 0.985 0.99 0.995 1 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% B-TOS Architecture Probability of Launch Success (Lifecycle total) Probability of Success Utility Cost of US Launch Policy: B-TOS Case Study Using Min Cost Rule 0.98 0.985 0.99 0.995 1 0 100 200 300 400 500 600 700 800 Lifecycle Cost ($M) A B C D Utility Cost 100% of B-TOS architectures have cost increase under restrictive launch policy for a minimum cost decision maker 98% of B-TOS architectures have increased launch probability of success under restrictive launch policy for a minimum cost decision maker Restrictive launch policy Unrestrictive launch policy Policy increases cost Policy increases launch probability of success B-TOS • Swarm of small sats. doing observation • Utility for multiple missions From Weigel, 2002 Space Systems, Policy, and Architecture Research Consortium ©2002 Massachusetts Institute of Technology 30 Using Architecture Models to Consider Uncertainty Performance and Cost move differently for different architectures under uncertainty TechSat • Constellation of satellites doing observation of moving objects on the ground • Uncertainties driven by instrument performance/cost From Walton, 2002 [Martin, 2000]
一 SSPARC Changes in User Preferences Can be Quickly Understood Architecture trade space reevaluated in less tha one hour User changed preference nting X-TOS SSPARC Assessing Robustness and Adaptability Pareto front shows trade-off of accuracy and cost Determined by number of satellites in swarm Could add satellites to increase capability ,吕海总 Most desirable architecture Cost
16 Space Systems, Policy, and Architecture Research Consortium ©2002 Massachusetts Institute of Technology 31 Changes in User Preferences Can be Quickly Understood 40 42 44 46 48 50 52 54 56 58 60 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Lifecycle Cost ($M) U t i l i t y 40 42 44 46 48 50 52 54 56 58 60 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Lifecycle Cost ($M) U t i l i t y Original Revised User changed preference weighting for lifespan Architecture trade space reevaluated in less than one hour X-TOS Space Systems, Policy, and Architecture Research Consortium ©2002 Massachusetts Institute of Technology 32 Assessing Robustness and Adaptability • Pareto front shows trade-off of accuracy and cost • Determined by number of satellites in swarm • Could add satellites to increase capability 0.98 0.985 0.99 0.995 1 100 1000 Lifecycle Cost ($M) Utility A D E C B Utility Cost Most desirable architectures B-TOS
SSPARC Questioning User Desires Best low-cost mission do only one job well More expensive, higher performance missions require more vehicles Higher-cost systems can do multiple missions Is the multiple mission idea a good one? Color scale: Life Cycle Cost, 1380 data points, grid: 75x75, density: 0. 08 A-TOS Swarm of very mple satellites taking ionospheric measurements creasing Several different Equatorial Utility SSPARC Understanding Limiting Physical or Mission constraints 4000.00 SPACETUG General purpose ort 3000.00 transfer 500.00 Different 200000 propulsion systems and 100000 Lines sho increasing fuel mass fraction Utllty (dimensionless) Hits a"wall"ofeither physics(can't change !) or utility(can)
©2002 Massachusetts Institute of Technology 33 Low Biprop Medium Biprop High Biprop Extreme Biprop Low Cryo Medium Cryo High Cryo Extreme Cryo Low Electric Medium Electric High Electric Extreme Electric Low Nuclear Medium Nuclear High Nuclear Extreme Nuclear 17 Space Systems, Policy, and Architecture Research Consortium • • • • Equatorial Utility High Latitude Utility A-TOS • Swarm of very simple satellites measurements • Several different missions Questioning User Desires Best low-cost mission do only one job well More expensive, higher performance missions require more vehicles Higher-cost systems can do multiple missions Is the multiple mission idea a good one? taking ionospheric Space Systems, Policy, and Architecture Research Consortium 34 0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00 3500.00 4000.00 0.00 0.20 0.40 0.60 0.80 1.00 Utility (dimensionless) Cost (M$) SPACETUG • General purpose orbit transfer vehicles • Different propulsion systems and grappling/obser vation capabilities • Lines show increasing fuel mass fraction ©2002 Massachusetts Institute of Technology Understanding Limiting Physical or Mission constraints Hits a “wall” of either physics (can’t change!) or utility (can)
SSPARC Integrated Concurrent Engineering (ICE ICE techniques from Caltech and JPL Linked analytical tools with human experts in the loop Very rapid design iterations Result is conceptual design at more detailed level than seen in architecture studies Allows understanding and exploration of design alternative a reality check on the architecture studies-can the vehicles called for be built. on budget with available technologies? SSPARC ICE Process(CON with MATE) Directed design Sessions allow very fast production of preliminary designs raditionally, design MATE allows utility be assessed real time synchronizes actio
Space Systems, Policy, and Architecture Research Consortium 35 • • • • • alternatives • ©2002 Massachusetts Institute of Technology Integrated Concurrent Engineering (ICE) ICE techniques from Caltech and JPL Linked analytical tools with human experts in the loop Very rapid design iterations Result is conceptual design at more detailed level than seen in architecture studies Allows understanding and exploration of design A reality check on the architecture studies - can the vehicles called for be built, on budget, with available technologies? Space Systems, Policy, and Architecture Research Consortium 36 Thermal Structures Communication Command and Data Handling Configuration Power Propulsion Attitude Determination and Control Mission Systems ICE-Maker Server Cost Reliability MATE ICE Process Leader computer tool AND human expert Verbal or online chat between chairs synchronizes actions Electronic communication between tools and server Key system attributes passed to MATE chair, helps to drive design session • Directed Design Sessions allow very fast production of preliminary designs • Traditionally, design to requirements • Integration with MATE allows utility of designs to be assessed real time ©2002 Massachusetts Institute of Technology ICE Process (CON with MATE) “Chairs” consist of 18
一 SSPARC ICE Result- XTOS Vehicle Early Designs had excessively large fuel tanks and bizarre Showed limits of coarse modeling done in architecture studies Vehicle optimized for best utility-ma life at the lowes practical altitude SSPARC SPACETUG Biprop One-Way GEO Tu 13 12 kg dry mass, 11689 kg wet mass Quite big(and therefore expensive); not very practical (?) Scale for all images: black ylinder is / meter ng by I meter in
Space Systems, Policy, and Architecture Research Consortium 37 • Early Designs had excessively large fuel tanks and bizarre shapes • Showed limits of in architecture studies • Vehicle optimized for best utility - maximum life at the lowest practical altitude ©2002 Massachusetts Institute of Technology ICE Result - XTOS Vehicle coarse modeling done Space Systems, Policy, and Architecture Research Consortium 38 • • Scale for all images: black cylinder is 1 meter long by 1 meter in diameter ©2002 Massachusetts Institute of Technology SPACETUG Biprop One-Way GEO Tug 1312 kg dry mass, 11689 kg wet mass Quite big (and therefore expensive); not very practical (?); 19