SpaceNet: Simulation Environment for Space Exploration Logistics Future In-Space Operations (FISO)...
-
Upload
lisa-wilson -
Category
Documents
-
view
221 -
download
0
Transcript of SpaceNet: Simulation Environment for Space Exploration Logistics Future In-Space Operations (FISO)...
SpaceNet: Simulation Environment for Space Exploration Logistics
Future In-Space Operations (FISO) Telecon Colloquium October 26, 2011 at 3pm Eastern Time
Prof. Olivier de Weck, Paul Grogan PhD candidate
Massachusetts Institute of Technology
2
Outline
• Introduction• Challenges of Space Logistics
– Time-varying launch opportunities– Nested complexity and object hierarchy– Asset management in -gravity
• SpaceNet Simulation Environment – Ontology of Space Logistics – Key Concepts– SpaceNet 2.5 – Discrete event simulation software– Four Application Case Studies
• Conclusions
MIT Strategic Engineering Research Group (http://strategic.mit.edu)
• Broad research agenda in Systems Engineering with a lifecycle focus
© Olivier de Weck, October 2011 Page 3
Strategic Engineering is the process of designing systems and products in a way that deliberately accounts for future uncertainties and attempts to maximize lifecycle value.
Research sponsors
J.Agte D.Asai T. Coffee S. Do P. Grogan T. Ishimatsu
C.Lee S. Nag N.ShougarianG. O’Neill S.W.Paek K. Sinha H. Yue
A. Alfaris A. Siddiqi G. Bounova
The ilities are desired properties of systems that often manifest themselves after a system has been put to initial use. These properties are not the primary functional requirements of a system’s performance, but typically concern wider system impacts with respect to time and stakeholders than embodied in those primary functional requirements.
Ilities – A Definition
Ref: de Weck O., Roos D., Magee C., “Engineering Systems: Meeting Human Needs in a Complex Technological World”, MIT Press, Fall 2011) - Chapter 4
B.Baker
O. de Weck
• Definition (http://spacelogistics.mit.edu)
– Space logistics is the theory and practice of driving space system design for operability, and of managing the flow of materiel, services, and information needed throughout the space system lifecycle.
4
LaunchLogistics
ISSResupply
In-SpaceRefueling
CampaignAnalysis
Asset Management
AIAA Space Logistics Technical Committee 2008-2010
Earth Mars: Time-varying Launch Opportunities
Ishimatsu T., Hoffman J., de Weck O.L., “Interplanetary Trajectory Analysis for 2020- 2040 Mars Missions Including Venus Flyby Opportunities”, AIAA-2009-6470, AIAA Space 2009 Conference & Exposition, Pasadena, California, September 14-17, 2009
Can only launchmissions every~ 26 months = time-expanded transportation. C3d Contour Plot [km2/s2]
Challenges of Space Logistics
Nested Complexity and Object Hierarchy• Pocket• Container• Carrier• Module• Segment• Compartment• Element• Pallet• Assembly• Facility*• Node• Vehicle
• Item
• Drawer
• Kit
• Locker
• Unit
• Rack
• Lab
• Platform
• MPLM
• Payload Bay
• Fairing
• Component
• Subsystem
• System
• SRU
• LRU
• ORU
• CTB
• M-01
• M-02
• M-03*In-Space Facility (e.g., the European Technology Exposure Facility (EuTEF)
M02 Bags
SupplyItems
MPLMRacks
MPLMCargoIntegration
MPLMIn Shuttle
Net cargo mass fractions are very low (<1% of launch mass).Tare mass matters.
Evans W., de Weck O., Laufer D., Shull S., “Logistics Lessons Learned in NASA Space Flight”, NASA/TP-2006-214203, National Aeronautics and Space Administration Technical Report, May 2006
Challenges of Space Logistics
Expedition 11 NASA ISS Science Officer John Phillips is working with cargo transfer bags inside the Quest Airlock
7
Asset Management in -gravity
8
Bar Code R eader
Multiple SSC/NGL
Clients
SSC/NGL File Server
DB
Communication occurs via Radio Frequency (RF) and is relayed through the RF Access Point located in the LAB
OCA Up
OCA Dow n
SSC/NGL Client
OCA Router
Tracking ~ 20,000 items
Manual bar-code based system
Relatively accurate system, but still ~ 3% of items are tagged as lost
Requires substantialmanual labor in spaceAnd on the ground (ISO)(>20’/day/crew)
Russian/NASAInventoryManagementSystem (IMS)
SpaceEarth
Automate real-timeasset management.Track parent-child relationships.
Shull S., Gralla E., de Weck O., Siddiqi A., Shishko R., “The Future of Asset Management for Human Space Exploration: Supply Classification and an Interplanetary Supply Chain Management Database”, AIAA-2006-7232, Space 2006, San Jose, California, Sept. 19-21, 2006
Challenges of Space Logistics
9
SpaceNet 2.5 Modeling and Simulation of Space Logistics
• Modeling space exploration from a logistics perspective• Discrete event simulation
– at the individual mission level (sortie, pre-deploy, re-supply,…)
– at the campaign (=set of missions) level
• Evaluation of manually generated exploration scenarios with respect to feasibility and measures of effectiveness
• Visualization of the flow of elements, agents and supply items through the “interplanetary” supply chain
• Optimization of scenarios according to selected MOEs• Provide software tool for users (= logisticians, mission
architects) to support trade studies and architecture analyses.
A computational environment for
http://spacenet.mit.edu Open Source Release 2.5.2 Sep 2011Under GNU General Public License
Building Blocks of SpaceNet• Nodes
– Surface, Orbital, Lagrange
• Objects– Supply Items, Elements, Crew (Agents)
• Network (Time-Expanded)– Time-dependent Edges
– Surface, Trajectory, Flight
• Events– Create, Transfer, Remove, Reconfigure, Demand
– Higher-level Processes (Transport, Exploration)
Slide 10
EventsSimulator
Nodes, Edges
Elements, Supplies
Domain
time = 4.2MOE1 = 39.294
MOE2 = 198.339
Read Events
Add Events
Alter State
Read State
Grogan P., Armar N., Siddiqi A., de Weck O., Shishko R. , Lee G., “Object Oriented Approach for Flexibility in Space Logistics Discrete Event Simulation”, AIAA-2009-6548, AIAA Space 2009 Conference & Exposition, Pasadena, California, September 14-17, 2009
Slide 11
• Assembly nearly complete • Lifetime extended to 2020
or beyond• Most critical resupply
vehicle retired (STS Shuttle)• Six or more vehicles to
participate in ISS operations• Analyze scheduled supply
versus estimated demands
Case 1: ISS Resupply
Image credit: NASA Slide 12
Grogan P.T., Yue H., de Weck O., “Application Case Studies for Flexible Space Logistics Modeling and Simulation using SpaceNet 2.5”, AIAA Space 2011 Conference & Exposition, Long Beach, California, September 27-29, 2011
Slide 13
ISS Resupply Scenario
Sept. 2010 – Dec. 2015: 77 missions
2 STS 22 Progress 22 Soyuz 12 Dragon
8 Cygnus 6 HTV 4 ATV 1 Proton-M
ISS Resupply Analysis
Slide 14
Demands
•10 tons/year spares
•15 tons/year science
•7.5 kg/person/day consumables
Results
•Supply capacity exceeds demands
•Existing stockpile can supply gaps
•Frequent resupply missions (every 20 days)
• Lunar south pole outpost buildup to continuous human presence
• Based on NASA LSSPO / CxAT-Lunar Scenario 12– Well-vetted case– Sufficiently detailed design
• Surface mobility elements:– Lunar electric rover (LER)– Tri-ATHLETE
Case 2: Lunar Outpost Campaign
Slide 15Image credit: NASA
Slide 16
Lunar Outpost Scenario
Sept. 2021 – Dec. 2028: 17 missions
2 sortie-style (1 un-crewed)
7 outpost-style
8 cargo resupply
Excursions to Malapert Crater and Schrödinger Basin
Lunar Outpost Analysis
Slide 17
• 7.5 kg/person/day consumables
• 1000 kg/year ISRU oxygen production
• 10% dry mass/year spares during crewed periods
• 5% dry mass/year spares during un-crewed periods
• Extra overhead mass for packaging (50-120% based on COS)
• Evaluate 2-person, 5-day exploration at asteroid 1999-AO10
• Constellation-style heavy-lift launch vehicle– Increased upper stage propellant– Increased service module propellant– Greatly expanded cargo capacity
• Significant assumptions:– No airlock in CEV – Zero-loss cryo-coolers– Restartable in-space stages– 7.5 kg/person/day demands
including packaging mass
Case 3: Near-Earth Object Sortie
Slide 18Image credit: NASA
Slide 19
Near-Earth Object Scenario
Sept. 2025 – Feb. 2026: 1 mission
2 crew members (7.5 kg/person/day demands)
Upper Stage reused for Earth departure and 1999-AO10 arrival
5-day exploration at 1999-AO10
NEO Sortie Analysis
Slide 20
• Small residual propellant values:
‒ Upper stage: 0.1%
‒ Service module: 0.2%
• Limited volume and mass capacity in CEV
• No ECLSS closure
• Cryogenic fuel losses
• No airlock for EVA exploration
• Technically “feasible” though not realistic
• A “flexible path to Mars”– Four interchangeable
missions– Use of propellant depots in
Earth and Mars orbit– Human/robotic exploration– Pirogue vehicle for human
exploration in the vicinity of Mars
• Builds on concepts in NASA Design Reference Architecture 5.0
Case 4: Mars Exploration Campaign
Slide 21Image credit: NASA
NASA/NIA 2010 RASC-AL Competition Winner
Slide 22
Mars Exploration Scenario
2034-2053: 4 flexible missions
Mars Tele-exploration Mission (MTM) – 3 kg returned (hoppers)
Phobos and Deimos Sorties (PDS) – 150 kg returned (Pirogue)
Phobos Exploration Mission (PEM) – 150 kg returned
Mars Surface Mission (MSM) – 250 kg returned
Slide 23
Mars Exploration Campaign Bat Chart in SpaceNet
Mars Exploration Analysis
Slide 24
Figure of Interest MTM PDS PEM MSMCampaign
TotalsAres V launches (mission payloads) 2 2 2 4 10Ares V launches (PRM payload) 6 6 6 11 29Crew launches 1 1 1 1 4Total mass in LEO (mT) 681.7 681.7 681.3 1,448.7 3,493.4Number of sites sampled 3 2 1 1 5Returned sample mass (kg) 3 150 150 250 553EDS propellant usage (mT) 510.9 510.9 511.9 1,019.1 2,552.8EDS propellant remaining (mT) 4.7 4.7 4.8 47.3 61.5Crew consumables demand (mT) 12.5 12.5 12.5 15.3 52.8Crew consumables remaining (mT) 1.2 1.2 1.2 12.3 15.9Robotic-days of exploration (robot-days) 360 0 0 1,060 1,420Human-days of exploration (human-days) 0 28 360 2,120 3,568
Overview of SpaceNet Modeling Flexibility
Slide 25
ISS Resupply
Lunar Outpost
NEO Sortie
Mars Exploration Campaign
Nodes 9 5 4 10
Edges 13 6 3 23
Missions 78 17 1 21
Events 271 156 6 337
Elements Types 14 30 11 32
Elements 90 140 12 234
Duration (days) 1,920 2,628 148 6,911
Conclusions
• Space Exploration Logistics is challenging and distinct from terrestrial logistics
• Key issues are launch windows, competition for manifest space, accommodation mass overhead ..
• Need to move from individual missions to campaigns of integrated missions (also for purely robotic missions)
• SpaceNet is a flexible and user friendly environment for integrated mission planning and logistics analysis
Slide 26
Slide 27Image credit: NASA
Questions?
spacenet.mit.edu
Acknowledgements:
– NASA Exploration Systems Mission Directorate for funds for SpaceNet 1.3 development
– Jet Propulsion Laboratory for support in developing SpaceNet 2.5
– DoD, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168a