Notes from Oliver de Weck Webseminar May 4 th, 2007 Spacenet: Architecting the Interplanetary Supply Chain

Transcription

1 Notes from Oliver de Weck Webseminar May 4 th, 2007 Spacenet: Architecting the Interplanetary Supply Chain Intro/ Slide 1 This work was developed at MIT. Myself and David Simchi Levi. And work with a company called PSI (planetary Science Institute) and JPL (Jet Propulsion Lab) Slide 2 Idea started Jan 14 th when President Bush announced a new direction in space exploration and the funding to go with it. CEV = Crew Exploration Vehicles CLV = Crew Launch Vehicles Ideas is mainly how to make space exploration = sustainable Slide 3 See the complexity of each types of mission Left = Apollo missions, KSC = Kennedy Space Center; self contained missions, nothing left behind on earth or in lunar orbit or on moon; So called backpack missions Middle - ISS = International Space Station - from a 51.6 degree inclination RSA = Russians at Bicanor (?) KSA = Kennedy, 6 month crew rotation, 4 logistics flights per year Basicisally a reply scheme Right = VSE - which is years out ATV = Europeans and HTV = Japanese - will both supply logistics ISS will be a supply noted LOP = Lunar Outposts Mars mission shown in dotted lines Overall much more complicated and the question is how can we make this manageable and affordable. Slide 4 The faction of the payload is very high for terrestrial supply chains: Ex 747 = 25% and a truck is much more than that. In space it is only 0.1% 93% = propellant 6.9% = dry mass of vehicle The 0.1% is the value of the system / mission - this consists of the crew, the consumables and experimentation equipment (exploration) We focused here because of the value sitting here This would be equivalent of you going on a month long trip and you can only take what would fit in your glove compartment! Slide 5

2 End of phase II right now Today May 4 th we are having NASA folks in for a final review See the terrestrial analogies for reference. Slide 6 Terrestrial = we typically think of SKUs - we need something more complex = Supply Class - it wasn t at first clear how to go about defining and organizing Before us - no single standard CCART = Cargo Categorization Rate Table - not sophisticated enough Military uses the middle 5 categories: for modeling systems, planning and insuringing consistency. We created the 10 categories - functionally based. There is a paper if you are interested in the details. from Alison McCaffree to All Participants: What do you do about duplicates We made sure that there were not duplicates. from H Griesser to All Participants:...or items that have multiple functions? Most are classified. Slide 7 LogicNet Plus 2.0 Shows a terrestrial network: blue = potential sites, red = exsisting sites, brown = manufacturing sites and green = customer sites. Right side shows how we use this tool to analyze performance Our challenge was to create something similar for space. Slide 8 HMP Research station on Devon Island = largest uninhabited (except when the scientists are there) island in the world. 25 degrees north Very dry = most similar to Mars Nasa and Canadian space agency are doing research here Crater is in a polar desert There are 3 long building housing research and quarters Greenhouse - for growing food. Slide 9 Shows Mars on top and Devon Island on the bottom = surprisingly similar. Slide 10 We spent 5 weeks at this site - exploring and testing - we wanted to do Supply Chain management for remote sites Jeff Houghman is testing the Hamilton Sunstrand spacesuit Lower right = telemetric studies and data is relayed back to Nasa and Canadaian Space Agency Total work = 683 crew days

3 Only way in was Twin Outer flights (bush planes) and we carried in 2300 item equally 20 Metric Tons - we inventoried Slide 11 Propellants are important Big hitter was transportation equipment Bar chart shows a comparison of what we found and other remote supply chains Slide 12 We networked in and out Node #3 was important - town of 200 Inowits natives with a dirt landing strip. It is the farthest north a Jet can land. Asymmetric between the inflows and the outflows from john grace to All Participants: Oli, do you account for items that you must return to your supply site or do you not consider this item? The reverse logistics are typically over looked. They included things like expensive communication equipment that needed to be repaired and anything that couldn t handle the harsh artic winter. We found we needed to smooth out the personnel profile - a spike in people was very difficult to handle. Robustness was more important than Optimization - due to flight availability due to things like weather. There is a report on this work if you want it. SpaceNet Slide 15 MOE = Measure of Effectiveness Slide 16 May look trivial but it took us many months of discussion to come up with because each mission is so different. - The trick was to generalize / abstract enough to have everything fall into these categories. 3 main building blocks: Nodes, Supplies and Elements Time Expression = time in discrete blocks and include the orbital dynamics Processes = details on each to come later. Slide 17 Network view - 2D planet and moon, with orbits shown in arcs Node doesn t necessarily mean that there is a facility there Arc = feasible trajectories = precomputed for fuel consumption etc, These are not always available - unlike in the terrestrial supply chain Launch windows come and go

4 Slide 18 Elements are not necessarily vehicles = all major end items Crew Cargo Propellant Attributes are all put into the configuration control database Slide 19 Propellant gives you the umf but not the carrying capacity Built Library of Space flight hardware Slide 20 Waiting - moves in time only Exploring - active science being done, although similar to waiting in time Any real scenario is a combination of these Slide 21 Time Extended = different trajectories Time in flight trade off with fuel Launch windows (shown in Pork chop chart) are distinct Key to Space Net = projected on network - only using allowable trajectories Slide 22 T-E Net definition Slide 23 MOE Definition useful = how effective is the mission In a terrestrial supply chain measurements of usefulness might be service level, % orders fulfilled, delay to the order being filled - they don t fully apply EC = how much useful science can be done - i.e. output for unit of input EC/Launch mass and normalized to the last Apollo mission. We use this measure because it was the last manned mission and it maximized the capabilities of the Apollo program Slide 24 Harvest ISRU = facility on the moon Slide 25 Tradespace - useful contour lines = because they are lines of efficiency Circle on Left (top dot) = return to moon - essentially 10x as efficient as the Apollo mission because of advancements in technology and we will have 4 crew land on the moon Middle Circle = The Apollo program is noted as a entirety. The Constellation mission will be a string of mission going to different locations Failed criteria = drop below the line

5 Usually means you go back to the same location and build infrastructure - i.e. a lunar outpost - take advantage of the mass you ve launched already from NASA HQ to All Participants: Can you comment on how the experimental data matched your predictions? We are having a meeting today with NASA to verify. See if our simulation of past mission match the data. I would say we are with in 3-5% of fuel and cargo capacity estimates The future simulations are a challenge because the vehicles are in development. Cargo Capacities change - if they need to take up more dry mass then that eats int ot he cargo and your capability is less then you had planned for from NASA HQ to All Participants: The measure of effectiveness assumes crew time on the surface is of the same value at all locations. Can you adapt the measure to reflect that some sites may have higher science value than others? Surface time = same value no matter when you go. In reality it would be less. If you go back to the same place 10 or 15 times increment value goes down each time. This would be a good refinement to the model. We d have to come up with a way to weigh the scientific value of the exploration and how it decreases each visit/ over time. Slide 26 Manifest is important = 0,1% = what you carry and this is basically what is left over after the other things are taken care of. Risk Management = with your safety margin increases then Exploration value decrease Every kg increase comes out of budget for surface cargo. Slide 27 Recent analysis relative to key demand parameters Best = 30 MT, 100% recycled, astronauts on diets and MTBF= twice as long as expected Worst = 75MT over a 3 year period. Sensitivity is import to the # of flight to make and how to make it sustainable Slide people ISRU = In-situ Resource Utilization New standard for models = credibility scale 1-4 where does this fall? Probably at about a 2. The usability assessment is by Johnson and Marshall Slide 29 Supply Chain is often neglected during planning and design Lots of academic use and NASA increaseingly using. There is an energetic group of students who have been engaged for 2 years. Slide 30

6 Strategic Engineer = Prof de Weck on department Others involved: IDAC = Interplanetary Design Analysis Cyucle Requirements for Constellation are being made and what to make it feasible A vert tense time - JPL/ MIT/ Payload system United Space Alliance = Boeing & Lockhead More Questions: from NASA HQ to All Participants: Will the SpaceNet tool be available for anyone to use? Spacenet lite will be generally available to the public. Past mission data is mostly in the public domain. Current info is not because it is in development and that is taken out for Lite from john grace to All Participants: Ccan you comment further on the credibility assessment standard and how you are relating to it? Credibility Assessment 7009 Level 1 = Research Environment Level 2 = Development - we are roughly here Level 3 = Production environment Level 4 = Highest integrity All models are rated so that when they are used in they know how much should the model be trusted. After the Columbia accident, this credibility assessment was started because it was not clear how reliable the estimates were when they were analyzing mission critical things. from NASA HQ to All Participants: Does it allow you to look at the trade-off between robotic and crew exploration? No - now we are only modeling Manned missions. If no crew then no exploration capability. Robotic and Tele-robotic missions this wouldn t be true. You might have a mix of manned and robotic. This would be a further refinement to account for both. We have not done that yet. And it is a domain question. We didn t put it in our domain for Space net.