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Lunar Architectures
Paul D. SpudisLunar and Planetary Institute
LEAG Meeting14 October 2013
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What is an architecture?
A series of payloads and missions,laid out in a sequence toachieve some strategic goal orcapability
Design choices are made, at leastat a conceptual level
Should be flexible enough to adaptto changing technicalrequirements, budgetary issuesand political undercurrents
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Previous Lunar Architectures1. Wernher von Braun’s Das Marsprojekt (1950)
Objective: Develop capability forEarth orbital, lunar andplanetary spaceflight
Strategic Approach: Incremental,launch vehicle, Earth orbitalstation, Moon tug with cislunarcapability, interplanetary flight
Tactical implementation: reusablelaunch vehicle, rotating spacestation in 1000 mile polar orbit,lunar tug with lander variant,Mars spacecraft
Alternatives: none
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Previous Lunar Architectures2. The Apollo Program (1961)
Objective: Within current decade,land man on the Moon and returnhim safely to the Earth
Strategic Approach: Build mega-rocket to fly complete mission inone or two launches (specificrefutation of step-wise,incremental approach previouslyadvocated by von Braun)
Tactical implementation: Saturn V(120 mT to LEO), Lunar OrbitRendezvous mission profile (CM-SM-LM)
Alternative: Soviet N-1 and Soyuz,Earth Orbit Rendezvous, one-man LK (failed)
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Previous Lunar Architectures3. Space Exploration Initiative (1989)
Objective: Return to the Moon,“this time, to stay.”
Strategic Approach: Usetechnology and hardware baseof Shuttle and SS Freedom tobuild OTV, staging nodes, lunarlander, lunar base
Tactical implementation: Shuttle-C,SS Freedom modules, OTV(RL-10 based).
Alternatives: Livermore “BrilliantCondoms” - inflatables launchedon EELV and derived vehicles
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Previous Lunar Architectures4. Vision for Space Exploration (2004)
Objective: Return to the Moon withgoal of living and working there forincreasing periods of time; preparefor future human Mars mission
Strategic Approach: Apollo-like: Ares VHLV to deliver fueled transfer stage,Altair lander, EOR with Orion,launched on smaller Ares I
Tactical implementation: Ares V (150mT), Ares I (25 mT), Orion CM,Altair lander (50 mT), multiple lunarsorties, build up to Mars mission(staged from Earth)
Alternatives: Shuttle-derived (SM or in-line), EELV-serviced cislunardepots, robotic-human compositelunar base
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So what are the difficulties?
Understanding the missionBiggest issue with VSE“Consensus is the absence of leadership.”
-- Margaret ThatcherResources - Trying to do too much with
too littleBlank sheet designs vs. adaptation of
existing capabilitiesSchedule pressure
Deadlines or not?Political and technical cycles
Technology fetishismNeed high-tech widget before x can happen
Hyper-conservative design ethicSafety vs. management of reasonable risks
Process valued more than resultsThe Cult of Management
NASA LEAG
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Some architectural principlesMoney
High initial upfront costs are undesirableBut similarly, back-ended mega-liens should
also be avoidedTotal program costs are less important than
rates of expenditureSchedule
In general, the longer an architecture, thegreater the total aggregate cost
However, the rate of expenditure tends to belower
Accomplish milestones at frequent intervalsCapability
Get technology development as a by-productof trying to do something
In broad terms, more new technology meansmore risk, greater aggregate cost, longertimescales (but greater capability at end)
The better is the enemy of the good enough
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Some architectural principles
Goals and ObjectivesWhat are you trying to do and WHY?Multiple objectives make for a more
costly, longer programHowever, architecture focused on some
narrow goal may be optimized forthat goal but will not serve othersadequately
“Destination-centric” is not the problemVariables
Optimizing for one variable (e.g., !v ormass) is a dumb strategy
Minimize number of branch points priorto attaining your objective, maximizethem after you achieve it
Launch vehicle choice dictates strategicapproach (heavy lift vs. depots)
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Re-thinking the architectural problem
Spaceflight is difficultThe Tyranny of the Rocket EquationReaching LEO with empty fuel tanks
Spaceflight is expensiveAccelerating tons of mass to Mach 25, lifting
it hundreds of km up along an extremelynarrow (few meter) path for thousands ofkm downrange is a very hard task
Precision machining, complex avionics,difficult-to-work materials
Spaceflight is barely possibleIf radius of Earth were 50% larger, the energy
in chemical bonds would not be sufficientto reach orbit
The benefits of spaceflight are not intuitivelyobviousHuman destiny, species survival, “Because
it’s there..” are not typical justifications formassive amounts of federal spending
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Or to put it another way….
Our ultimate goal in space is to goanywhere, anytime with asmuch capability as we need
Spacecraft are mass- and power-limited and thus, capability-limited
They will remain so as long as weare restricted to what can belifted out of Earth’s gravity well
This restriction negatively impactsscientific capabilities,economic health, and nationalsecurity
To extend reach and capability, we must learn to usewhat we find in space to create new space faring
capabilities
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Cislunar Space: A New Strategic Arena?
Cislunar: the volume of spacebetween Earth and Moon
Zones of cislunar spaceLEO, MEO, GEO, HEO, L-
pointsDifferent assets located at
different levels of cislunarNeed freedom of movement for
machines, peopleModern national strategic needs
depend critically upon ability touse our satellite assets
Space power projection involvesboth protection of assets anddenial of assets to an adversary
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Lessons from Shuttle and Station ProgramsLarge, distributed systems too big
to be launched from Earth canbe assembled in space
Humans and machines workingtogether can assemble, serviceand maintain complex spacesystems
Applying this paradigm to trans-LEO (cislunar) space requiresdevelopment of a transportationsystem that is affordable,extensible, and reusable
Developing the resources of the Moon enables thecreation of such a system (if you can reach the Moon,
you can access any other point in cislunar space)
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The Value of SpaceModern industrial civilization depends
critically on numerous satellite assetsin high orbits above LEO:GPS and navigationGlobal communicationsRemote sensing, weatherSurveillance and national security
assetsWe cannot access those satellites to
maintain them or to build large,distributed space systems
If we could access those satellites withhumans and robots, new capabilitiesfrom space assets could be created,ensuring ourselves a better quality oflife, a bigger and stronger economy,and a more secure world
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Space faring: Changing the RulesCurrent template
Custom-built, self-contained, mission-specific spacecraft
Launch on expendable vehiclesOperate for set lifetimeAbandon after useRepeat, repeat, repeat
New templateIncremental, extensible building
blocksExtract material and energy
resources of space to use in spaceLaunch only what cannot be
fabricated or built in spaceBuild and operate flexible, modular,
extensible in-space systemsMaintain, expand and use indefinitely
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Goals and PrinciplesExtend human reach beyond LEO by
creating a permanent, extensiblespace faring infrastructure
Use the material and energy resourcesof the Moon to create this system
Lunar return by small, incremental,cumulative steps
Proximity of Moon permits progressprior to human arrival via roboticteleoperations
Innovative space systems: fuel depots,robotics, ISRU, reusable spacecraft,staging nodes
Schedule is free variable; constant,steady progress but no deadlines
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Architectural ImplicationsUse robotic flights to acquire strategic
knowledge and emplace assetsrobotic missions are not just for
scienceCommonality of hardware, systems,
procedures between robotic andhuman flight elementstest human flight components on
robotic missionsLocate “high grade” lunar resources
and build human habitats nearbyconcentrated resources (e.g., polar
ice) are easiest to use; focus onthem first
Build up infrastructure in a singlelocation to create capability rapidlyForget sorties: pick the site and build
up an outpost
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MissionCreate a permanent human-tended lunar outpost
to harvest water and make propellantApproach
Small, incremental, cumulative stepsRobotic assets first to document resources,
demonstrate production methodsAssume water abundance of 10 wt.%Teleoperation of robotic mining equipment from
Earth. Emplace and build outpost assetsremotely
Use existing LV, HLV if it becomes availableCost and Schedule
Fits under existing run-out budget (< $7B/year, 16years, aggregate cost $88 B, real-yeardollars)
Resource processing outpost operational halfwaythrough program (after 18 missions); endstage after 30 missions: 150 mT water/yearproduction (break-even)
BenefitsPermanent space transportation systemRoutine access to all cislunar space by people
and machinesExperience living and working on another world
An Affordable Lunar Return ArchitectureP.D. Spudis and A.R. Lavoie (2011) Using the Resources of the Moon to Create a Permanent Cislunar Space
Faring System. Space 2011 Conf, Long Beach CA, AIAA 2011-7185, 24 pp.
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Initial Steps
1. Communication/navigation satellitesPolar areas out of constant Earth LOS;
need comm, positional knowledge2. Polar prospecting rovers
Study and characterize water deposits,other substances, environment
3. ISRU demoHeat icy regolith to extract water; purify
and store as ice in cold traps4. Digger/Hauler rovers
Excavate regolith, transport feedstock tofixed stations for water extraction
5. Water tankersPurify and store extracted water
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Next Steps
6. Electrolysis unitsCrack water into hydrogen and oxygen;
liquefy into cryogens7. Supporting equipment
Robotic Landers - medium (500 kgpayload), heavy (2 mT payload)
Power plants - extendable solar arrays,steerable on vertical axis to track sun atpoles
Cryo storage - store LOX, LH2 (use coldtraps, 25 K)
Material Fabricators - Process regolith forrapid prototype products and parts
8. Space-based assetsLEO depot - fuel lunar departure stagesLLO depot - staging node for reusable
cargo and human landers
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HumanLander (HL) Zone
Blast Berm
Blast Berm
Beacons
Beacons
HL SupportCart
RWTL SupportCart
Portable Communication Terminal
Habitation Zone
RWTL Zone
Pressurized Transfer Vehicle
Unpressurized ISRU Lab
Living Cluster
Regolith Waste
Outpost Layout Concept
PropellantManufacturing Zone
Water Ice Deposit
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Manifest and Schedule
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Augustine run-out budget
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Program SummaryCreate a permanent, cislunar space
transportation system based upon theharvest and use of lunar water
Most infrastructure is emplaced andoperated robotically; people comewhen facilities and budgets are ready
Small incremental steps that build uponeach other and work together
Progress continually made, regardless ofbudgetary issues in any given year
Incremental approach greatly facilitatesboth commercial and internationalparticipation
Cislunar system created here is a“transcontinental railroad” in space,opening up the space frontier
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Value Returned for Money SpentCreate an extensible, reusable cislunar
space transportation system basedaround the use of the resources of theMoon
Such a space transportation system has theinherent capability to take us to theplanets
Obtain a permanent foothold on anotherplanetary body (the Moon) for the firsttime in human history
Develop the means to build large, high-power distributed space systems toserve a variety of national andinternational economic, scientific andsecurity objectives
Become a true space-faring species;learning to use off-planet resources isthe first step of settlement
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Is it possible to devise a sustainablearchitecture for lunar return?
YesIncremental approach that reaches notable milestones on a recurring, continuous
basisAchieves some capability of recognized societal valueLeads logically to next step (no isolated accomplishments)
NoPolitical system makes space goals beyond 3-4 year time horizon untenableShrinking fraction of federal budget available for spacePanem et circenses mentalityAgency is not configured for a long-range, strategic program
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What Kind of Space Program?Two Visions
“A spectacular series of space ‘firsts’”(Augustine report, 2009)Launch, use and discardEverything comes up from EarthOne-off, PR “stunt” missionsAccomplish the feat and cancel the programFlags and footprints foreverCostly and subject to political and fiscal
winds of changeBecome a true space faring species
Reusable, maintainable, extensible spacesystems
Incremental, cumulative, steady progressionoutward
Fit under any budget envelope; return valuefor money spent
Government develops and demostechnology; commerce follows
Create a permanent and expanding spacetransportation infrastructure
Less glitter, more substance
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Space – A New Rationale“If God wanted man to become a space-faring species, He would have given man a Moon.”
Krafft Ehricke
Explore to broaden ourknowledge andimagination base
Prosper by using theunlimited energy andmaterials of space toincrease our wealth
Secure our nation andthe world by using theassets of space toprotect the planet andourselves