NexGen Space LLC Page 1 Evolvable Lunar Architecture
Economic Assessment and Systems Analysis
of an Evolvable Lunar Architecture that
Leverages Commercial Space Capabilities and Public-Private-Partnerships
This study by NexGen Space LLC (NexGen) was partly funded by a grant from NASA’s
Emerging Space office in the Office of the Chief Technologist. The conclusions in this
report are solely those of NexGen and the study team authors.
Date of Publication
July 13, 2015
Charles Miller, NexGen Space LLC, Principal Investigator
Alan Wilhite, Wilhite Consulting, Inc., Co-Principal Investigator
Howard McCurdy, American University
Edgar Zapata, NASA KSC
Independent Review Team
Joe Rothenberg, former NASA Associate Administrator for Spaceflight (Chairman)
Gene Grush, former NASA JSC Engineering Directorate (Technical subsection lead)
Jeffrey Hoffman, MIT Professor, former NASA astronaut (S&MA subsection lead)
David Leestma, former NASA astronaut, (Cost Estimation subsection lead)
Hoyt Davidson, Near Earth LLC, (Business Risk Management subsection lead)
Alexandra Hall, Sodor Space, (Public Benefits subsection lead)
Jim Ball, Spaceport Strategies LLC
Frank DiBello, Space Florida
Jeff Greason, XCOR Aerospace
Ed Horowitz, US Space LLC
Steve Isakowitz, former NASA Deputy Associate Administrator for Exploration
Christopher Kraft, former Director NASA Johnson Space Center
Michael Lopez-Alegria, former NASA astronaut
Thomas Moser, former NASA Deputy Associate Administrator for Human Spaceflight
James Muncy, Polispace
Gary Payton, former NASA astronaut, former Deputy Undersecretary for Space, USAF
Eric Sterner, former NASA Associate Deputy Administrator for Policy and Planning
Will Trafton, former NASA Deputy Associate Administrator for Spaceflight
James Vedda, Aerospace Corporation
Robert Walker, former Chairman of the House Committee on Science and Technology
Gordon Woodcock, consultant
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Table of Contents
EXECUTIVE SUMMARY ............................................................................................... 4
STUDY ASSUMPTIONS .................................................................................................. 6
1) PUBLIC PRIVATE PARTNERSHIPS AS ACQUISITION STRATEGY ...................................... 6
2) 100% PRIVATE OWNERSHIP OF LUNAR INFRASTRUCTURE AND ASSETS ....................... 8
3) INTERNATIONAL LUNAR AUTHORITY TO REDUCE BUSINESS RISK ............................... 9
4) EVOLVABLE LUNAR ARCHITECTURE ............................................................................ 9
TECHNICAL ANALYSIS .............................................................................................. 11
GENERAL TECHNICAL APPROACH .................................................................................. 11
ANALYSIS METHODS ...................................................................................................... 12
PHASE 1A — ROBOTIC SCOUTING, PROSPECTING, SITE PREPARATION .......................... 13
PHASE 1B — HUMAN SORTIES TO LUNAR EQUATOR ..................................................... 19
PHASE 2 — HUMAN SORTIES TO POLES .......................................................................... 23
PHASE 3 — PROPELLANT DELIVERY TO L2 & PERMANENT LUNAR BASE ...................... 25
PHASE 4+ (OPTIONAL) — REUSABLE OTV BETWEEN LEO AND L2 ............................... 27
TECHNICAL RISK ASSESSMENT ...................................................................................... 28
LIFE CYCLE COST ESTIMATES ............................................................................... 30
BASIS OF ESTIMATE ........................................................................................................ 30
Ground Rules ............................................................................................................. 30
Assumptions ............................................................................................................... 31
HISTORICAL DATA .......................................................................................................... 32
MODELING & ANALYSIS - SCOPE ................................................................................... 34
Modeling & Analysis – Drivers ................................................................................. 35
Modeling & Analysis – Context, the NASA Budget ................................................... 35
LIFE CYCLE COST ASSESSMENT - RESULTS .................................................................... 37
Frequently Asked Questions ...................................................................................... 45
Life Cycle Cost Assessment – Results Summary ........................................................ 46
Life Cycle Cost Assessment – Forward Work ........................................................... 46
MANAGING INTEGRATED RISKS ........................................................................... 48
RISK STRATEGIES TO MITIGATE LOSS OF LAUNCH VEHICLE .......................................... 50
RISK STRATEGIES TO MITIGATE LOSS OF IN-SPACE ELEMENTS ..................................... 54
RISK STRATEGIES TO MITIGATE LOSS OF LUNAR LANDER OR ASCENT VEHICLES ......... 56
RISK STRATEGIES TO MITIGATE LOSS OF SURFACE ELEMENTS ...................................... 57
RISK STRATEGIES FOR MITIGATING LOSS OF CREW OR LOSS OF MISSION ...................... 58
RISK STRATEGIES FOR MITIGATING CREW HEALTH AND MEDICAL CONDITIONS ........... 59
CONCLUSIONS FOR INTEGRATED RISK MANAGEMENT ................................................... 60
MITIGATING BUSINESS RISKS ................................................................................ 63
WEAKNESSES OF PPP MODEL ........................................................................................ 63
MITIGATING BUSINESS RISK WITH AN INTERNATIONAL LUNAR AUTHORITY ................. 64
GOVERNANCE CASE STUDIES ............................................................................... 67
Port Authority of NY-NJ ............................................................................................ 67
CERN ......................................................................................................................... 70
Tennessee Valley Authority ....................................................................................... 72
COMSAT-INTELSAT ................................................................................................. 74
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AT&T (Monopoly, Regulated Utility) ........................................................................ 77
Boeing-United Airlines Monopoly ............................................................................. 78
National Parks & Private Tourism ............................................................................ 79
McMurdo Station (Antarctica) .................................................................................. 80
Open Architectures — Increasing Private Investment & Accelerating Innovation .. 83
CASE STUDY FIGURES OF MERIT (FOMS) & SUMMARY AOA ........................................ 86
PROS OF INTERNATIONAL LUNAR AUTHORITY ............................................................... 87
CONS OF INTERNATIONAL LUNAR AUTHORITY .............................................................. 88
PUBLIC BENEFITS ....................................................................................................... 89
ECONOMIC GROWTH ...................................................................................................... 89
NATIONAL SECURITY ..................................................................................................... 89
DIPLOMATIC SOFT POWER .............................................................................................. 89
TECHNOLOGY AND INNOVATION .................................................................................... 90
SCIENTIFIC ADVANCES ................................................................................................... 92
STEM EDUCATION AND INSPIRATION ............................................................................ 92
SUSTAINING AND MAXIMIZING THE PUBLIC BENEFITS ................................................... 93
APPENDIX A — STUDY TEAM BIOGRAPHIES ..................................................... 94
APPENDIX B — INDEPENDENT REVIEW TEAM BIOS ...................................... 97
END NOTES .................................................................................................................. 100
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This study’s primary purpose was to assess the feasibility of new approaches for
achieving our national goals in space. NexGen assembled a team of former NASA
executives and engineers who assessed the economic and technical viability of an
“Evolvable Lunar Architecture” (ELA) that leverages commercial capabilities and
services that are existing or likely to emerge in the near-term.
We evaluated an ELA concept that was designed as an incremental, low-cost and
low-risk method for returning humans to the Moon in a manner that directly supports
NASA’s long-term plan to send humans to Mars. The ELA strategic objective is
commercial mining of propellant from lunar poles where it will be transported to lunar
orbit to be used by NASA to send humans to Mars. The study assumed A) that the
United States is willing to lead an international partnership of countries that leverages
private industry capabilities, and B) public-private-partnership models proven in recent
years by NASA and other government agencies.
Based on these assumptions, the our analysis concludes that:
• Based on the experience of recent NASA program innovations, such as the COTS
program, a human return to the Moon may not be as expensive as previously
• America could lead a return of humans to the surface of the Moon within a period
of 5-7 years from authority to proceed at an estimated total cost of about $10
Billion (+/- 30%) for two independent and competing commercial service
providers, or about $5 Billion for each provider, using partnership methods.
• America could lead the development of a permanent industrial base on the Moon
of 4 private-sector astronauts in about 10-12 years after setting foot on the Moon
that could provide 200 MT of propellant per year in lunar orbit for NASA for a
total cost of about $40 Billion (+/- 30%).
• Assuming NASA receives a flat budget, these results could potentially be
achieved within NASA’s existing deep space human spaceflight budget.
• A commercial lunar base providing propellant in lunar orbit might substantially
reduce the cost and risk NASA of sending humans to Mars. The ELA would
reduce the number of required Space Launch System (SLS) launches from as
many as 12 to a total of only 3, thereby reducing SLS operational risks, and
increasing its affordability.
• An International Lunar Authority, modeled after CERN and traditional public
infrastructure authorities, may be the most advantageous mechanism for
managing the combined business and technical risks associated with affordable
and sustainable lunar development and operations.
• A permanent commercial lunar base might substantially pay for its operations by
exporting propellant to lunar orbit for sale to NASA and others to send humans to
Mars, thus enabling the economic development of the Moon at a small marginal
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• To the extent that national decision-makers value the possibility of economical
production of propellant at the lunar poles, it needs to be a priority to send robotic
prospectors to the lunar poles to confirm that water (or hydrogen) is economically
accessible near the surface inside the lunar craters at the poles.
• The public benefits of building an affordable commercial industrial base on the
Moon include economic growth, national security, advances in select areas of
technology and innovation, public inspiration, and a message to the world about
American leadership and the long-term future of democracy and free markets.
An independent review team — led by Mr. Joe Rothenberg, former head of NASA
human spaceflight — and composed of former NASA executives, former NASA
astronauts, commercial space executives, and space policy experts — reviewed our
analysis and concluded that “Given the study scope, schedule and funding we believe the
team has done an excellent job in developing a conceptual architecture that will provide
a starting point for trade studies to evaluate the architectural and design choices.”
DISCLAIMER: This was a limited study that evaluated two specific technical approaches
for one architectural strategy that leverages commercial partnerships to return to the
Moon. We did not evaluate all alternatives for returning to the Moon, nor did we evaluate
using similar partnership methods for alternative destinations or purposes. While funded
by NASA, the conclusions in this study are solely those of the NexGen study team authors.
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The primary economic research question of this study was:
“Could America return humans to the Moon, and ultimately develop a permanent
human settlement on the Moon, by leveraging commercial partnerships, within
NASA’s existing deep space human spaceflight budget of $3-4 billion per year?
The key study assumptions for this analysis included:
1) Public Private Partnerships as Acquisition Strategy
A significant purpose of this study is to assess the utility of public-private
partnerships — specifically the proven Commercial Orbital Transportation Services
(COTS)/ ISS Cargo Resupply Service (CRS) model —for private-sector lunar
development. These approaches have now been proven to be effective at significantly
reducing costs. While the focus of this study was on returning humans to the Moon,
these same methods could be used for alternative destinations.
In the last decade, NASA has transitioned from a government-owned and –operated
cargo delivery system to the International Space Station (ISS) to a privately-owned and –
operated cargo delivery system with multiple competitors. NASA achieved this major
transition by creating a public-private-partnership. Instead of a traditional acquisition
approach, NASA used a linked two-part acquisition strategy summarized as follows:
1. NASA first signed “funded Space Act Agreements” (fSAAs) with significant
investments by both NASA and industry, to demonstrate new system level
capabilities that did not exist before. This program was called COTS.
2. The NASA CRS program, used FAR part 12, commercial terms, firm-fixed price
(FFP) contracts to acquire cargo delivery services after the partners had proven they
had the capability in COTS.
The result was successful development of two brand new launch vehicles (SpaceX’s
Falcon 9 and Orbital’s Antares), two new American ISS cargo delivery spacecraft
(Dragon and Cygnus) — at costs much less than was possible using traditional
These two acquisition tools — the fSAAs and the FFP FAR part 12 (commercial
terms) contracts — were critically linked. In this specific situation, each element worked
together to achieve all of NASA’s objectives. Further, NASA analysis demonstrates that
the fSAAs saved NASA many billions of dollars as compared to traditional NASA
These successes have helped NASA quickly replace critical functions previously
provided by the Space Shuttle at a time of significant budget constraints.
Cost Savings from the COTS/CRS Acquisition Model
In 2010, NASA conducted a study
that compared SpaceX’s actual costs to develop
the Falcon 9 and Dragon spacecraft against what NASA’s cost models predicted it would
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cost using traditional cost-plus methods under federal acquisition regulations (FAR).
Using the NASA-AF Cost Model (NAFCOM), NASA estimated that it would have cost
NASA $3.977 Billion to develop these systems using traditional contracting methods.
The reported SpaceX cost was $443 million
, which would be an 89% (or 8-to-1)
reduction in costs over NASA’s estimated cost for the traditional approach.
Policy History of COTS/CRS
The CRS program was created in the aftermath of the Columbia Accident by the Bush
(43) Administration as the “Commercial Crew/Cargo Program”. However, COTS was
created later, in 2005, by NASA Administrator Mike Griffin. Griffin decided to use
NASA’s “other transactions” authority (OTA) to fund development of commercial
systems in a much more streamlined manner. Griffin explained
his thinking about this
innovative strategy to the NASA JSC Oral History project:
• “The question was how to get that started. In my view, a good way to get that started
would be to make available to successful commercial developers the government
market, and even to provide them a little bit of seed money.”
• Using the In-Q-Tel model, one could achieve valid public purposes with a little bit of
public money, while not corrupting the market.
• The way we structured it, according to what I had in mind, was through Space Act
Agreements which themselves would be competed for.
• The idea was that we would make available milestone payments to companies who
were working on their own private goals to develop space transportation systems. If
they met milestones of interest to us—and we published what those milestones were—
then they would get payments.
• We would not be involved in reviewing the designs or the development practices of
the companies involved. They would have to bring the products to market in their own
way, in their own time, by their own means, according to their own standards.
• I think everybody knew that the industry had reached a maturation point where the
technical and managerial skills to develop commercial spaceflight capabilities were
out there, and that what was lacking was any form of market. No matter how you cut
it, the initial market was going to have to be government. Then once you got over
those barriers to entry, maybe other purely commercial markets could develop. No
one knew what those were, and I don’t know what those are today. But you would
never have an opportunity to find out if you couldn’t get over the initial barriers to
entry, and government could help with that.
Four Successes in a Row for COTS/CRS Model
What we call the COTS model — which uses the U.S. Government’s “other
transactions authority” (OTA) via funded Space Act Agreements — has now developed
four (4) new American launch vehicles in a row, when you account for the Atlas V and
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Delta IV. These launchers were developed using nearly identical commercial partnership
The Atlas V and Delta IV were developed by Lockheed Martin and Boeing,
respectively, with commercial methods and processes, large private investments, and a
significant (but minority) government investment. The U.S. Department of Defense
invested $500 million in each project using OTAs as true partners, with Lockheed and
Boeing privately investing several billion dollars each. Since each firm invested
significant amounts of capital, for which they would only earn a return if it succeeded and
flew successfully and often, the interests of the partners were aligned. The U.S.
Department of Defense was willing to accept a secondary role with insight, but minimal
USG oversight and control during the development phase
Both of these new launch vehicles were developed in about four (4) years, which was
the same amount of time required to develop the Falcon 9 and Antares launch vehicles.
All of these launch systems succeeded on their first try.
SpaceHab Independently Validates COTS/CRS Model
NASA has used similar public private partnership methods in the past that resulted in
great success, as well as savings to the American taxpayer. SpaceHab was a commercial
microgravity firm that raised private venture financing to commercially develop its
patented pressurized mid-deck Shuttle modules. Of that amount, about $150 million was
spent on DDT&E and manufacturing two flight modules
. This private financing was
substantially based on a contract to sell commercial mid-deck locker services to NASA,
and augmented by the potential of other commercial markets.
The U.S. Congress mandated that NASA conduct an independent cost assessment of
what it would take NASA to develop the SpaceHab system using traditional government
procurement practices. Price Waterhouse worked with MSFC and used MSFC’s standard
cost model tool to estimate
that it would have cost NASA $1.2 Billion, which was 8
times more than SpaceHab spent using commercial practices and methods. SpaceHab
demonstrated the same nearly order of magnitude cost savings that SpaceX demonstrated
almost two decades later.
Implications for Cost Assessment
The NexGen study team had access to the data described above, as well as significant
additional technical and cost information from many other space projects during the
conduct of this study. This is discussed in much greater detail in the section on Life
Cycle Cost Estimation starting on page 30.
2) 100% Private Ownership of Lunar Infrastructure and Assets
We assume private ownership of lunar infrastructure and systems. We did not
identify any requirement for USG ownership of any of the lunar infrastructure elements.
Private ownership and responsibility for infrastructure is critical to driving market-based
incentives, decision-making, and efficiencies. NASA can achieve its public purposes and
meet NASA’s needs by serving as customer of commercially-provided services.
NASA has stated that "We're going to spend a 10-year period of time between 2020
to 2030 in cis-lunar space, trying to establish an infrastructure in lunar orbit from which
we can help entrepreneurs, international partners and the like who want to get down to
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the surface of the moon."
This architecture assumes as a baseline that NASA will not
lead a return to the Moon, as stated by current NASA leadership, although it may support
entrepreneurial lunar surface activities in pursuit of its journey to Mars. This study
investigates one particular approach, and implementation of, such NASA support.
3) International Lunar Authority to Reduce Business Risk
There are significant implications of the private ownership of assets, as it transfers the
majority of the development risk to private industry. The cost and risk of developing a
lunar base — even with NASA and other country’s space agencies as anchor tenant
customers — is far beyond that which conventional requirements for risk-adjusted return
on investment will accept or allow. The combination of very large financial
commitments, technical risk, and dependence of government’s keeping their
commitments, makes this an extra-ordinary risk.
More important than anything, industry must be convinced that NASA and other
space agencies will honor and keep their long-term commitments for lunar-based
services. It is imperative that the U.S. Government not change its mind and break its
commitment 2, 4 or 8 years later when we get a change of Congress or a change in
President and NASA Administrator. However, given recent history, it is difficult to
imagine industry trusting that NASA can keep such a commitment without significant
Effectively managing this risk is a critical priority for the success of this model. In
the section on “Managing Business Risk”, starting on page 63, we will provide analysis
on various alternatives to mitigate this risk. Our recommended solution based on the
analysis of alternatives is the creation of an International Lunar Authority that is modeled
after a combination of CERN and traditional public infrastructure authorities used in
airports and seaports around the world.
4) Evolvable Lunar Architecture
The evolvable lunar architecture, which leverages commercial partnerships, that was
assessed by NexGen was a 3-phase, step-by-step development of a lunar base. To the
maximum extent possible, it uses existing and proven technologies in the current phase of
development, and in parallel developed key technologies necessary for the next phase.
The key decision point for transitioning to the next phase was driven, in part, by a few
key technology developments.
This step-by-step approach allows for the incremental development and insertion of
reusable elements in a low-risk phased manner that minimizes cost and risk. This was a
critical aspect of the ELA, which will be covered in more detail in which is discussed at
length in a section focused on our strategy to mitigate technical risk starting on page 48.
There were three phases to the NexGen Evolvable Lunar Architecture (ELA):
Phase 1: Human Sorties to the Equator/Robotic Scouting of Poles
Phase 1 was designed with three independent activities taking place in parallel:
• The robotic segment would focus on characterizing the amount and nature of the
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water in the lunar poles, to enable later prospecting, and to identify the optimal
site for a lunar base.
• The human transportation segment would focus on developing and demonstrating
the key systems for returning humans to the Moon, including the in-space
transportation (a reusable crew capsule for transporting humans to lunar orbit and
returning them safely to Earth), and a lunar lander.
• The technology segment would develop the technologies needed in Phase 2, such
as propellant storage and transfer.
The Key Decision Point (KDP) to begin Phase 2 is the successful demonstration of
human landing at the equator and with the successful demonstration of propellant storage
and transfer capability needed for transferring human systems to a lunar polar orbit in
Phase 2: Sorties at Poles & ISRU Capability Development
The focus of Phase 2 is human sorties at the lunar poles, and developing the key
capabilities and technologies needed for Phase 3. This is a stepwise transition phase that
• Development of lunar surface ISRU capabilities and technologies to mine the
lunar ice, and convert the water into propellant
• Development of a large reusable LOX-H2 lunar lander, including reliable
cryogenic LOX/H2 engines and propellant depots.
• Completion of the robotic scouting mission, and selection of the site for the
permanent lunar mining base.
The KDP for Phase 3 is when lunar water ISRU, cryogenic LOX/H2 storage and
transfer, and a large reusable lunar lander are all available. The reusable lunar lander will
have the ability to transport propellant to the L2 depot and return, to transport large
structures from lunar orbit to the lunar surface, and safely transport humans to/from the
Phase 3: Permanent Lunar Base transporting propellant to L2
The focus of Phase 3 is the operations of a large-scale mining lunar water, cracking of
the water into lunar propellant, storage of the propellant, and transfer of 200 metric tons
of propellant per year to a propellant depot at the Earth-Moon L2 station. To achieve this
objective, a permanent lunar base for a crew of 4 is first developed using the lunar ISRU
and reusable lunar lander. The purpose of the crew is to operate, maintain, and repair the
mostly automated ISRU equipment.
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General Technical Approach
For the three-phase Evolvable Lunar Architecture (ELA), space transportation
systems and supporting infrastructure were designed and analyzed from initially
providing access to the lunar surface to the development of a permanent human outpost
supporting the production of lunar resource propellant for deep space exploration (Figure
T-1). Phase 1 includes robotic prospecting for lunar ice at the poles to determine if
exploitable ice does exist and human lunar equatorial surface access for demonstrating
key space transportation systems and key life support systems. In addition technology
will be developed for in-situ resource utilization (ISRU) mining and production of
LOX/LH2 propellants, in-space propellant storage and transfer for lowering space
n costs and
Phase 2 will
test a human
to the lunar
the technologies developed in Phase 1. In order to evolve to Phase 3, technology
development is required for reusable rocket propulsion for routine access to the surface
and for delivering LOX/LH2 propellant to a depot in L2 with a reusable lunar module. In
addition, an ISRU mining and production plant is developed for delivery and startup in
Phase 3. Thus in Phase 3, LOX/LH2 is produced and delivered to L2 with a reusable
lunar module and is being tended by a crew of 4 in a permanent lunar outpost. Although
not studied, a similar evolvable Mars architecture can make use of space proven
transportation, habitat, and ISRU systems and technology. Thus the next step of Mars
human exploration requires the development of human and electronic radiation protection
and entry/descent/landing of cargo and crew.
At each phase, we use to the maximum extent existing systems and proven
technologies as shown in Figure T-1. For new systems and technology, a measured
approach was used — focused technology development, technology demonstrations,
small scale pilot systems, full-scale systems development, and in-space systems testing to
mitigate the initial risks to the crew and maximize mission success for each phase. High
risk technologies and system demonstrations incorporate a number of planned failures,
evolution development, and/or alternate strategies. Thus, each technology demonstration,
system test, and phase completion milestone represents a key decision point in the
program for continuation with risk, replan with reinvestment, or cancellation.
Figure T-1. Program Integration of Technology, Development, and Missions
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For the design and analysis of the space system architecture, various analysis methods
were used. Because of the limited resources and time for this study, literature search
provided much of the fundamental data and where appropriate conceptual design tools
were used for vehicle sizing and geometry design.
Space system performance, deltaV, was defined for each leg of the space transfer as
shown in Figure T-2. For Earth-moon transfer, the deltaV is taken the maximum actually
used for the seven Apollo moon missions
. However, for the Apollo descent trajectory,
there was a flight path angle hold for the pilot to view the landing site for large boulders
or small craters (7% penalty); and for the final approach, there were six hover maneuvers
for pilot attitude and speed corrections. In addition, there were additional contingencies
for engine-valve malfunction, redline low-level propellant sensor, and redesignation to
another site (9% penalty). In this study, it was assumed that the landing sites are fully
defined, advanced laser sensors for remote site debris and crater checkout, and modern
propellant and engine sensors for measuring and establishing final engine performance.
In addition, the final descent time was reduced from the 45 seconds baselined in Apollo
to 30 seconds at a decent velocity of 0.1 m/s. For polar lunar missions, the cis-lunar
performance was taken from NASA’s Exploration Systems Architecture Study that
provided the baseline systems for NASA’s Constellation program
The performances of transfers from Earth to Earth-moon L2 and from there to Mars
orbit were taken from various references
. The selected data are for direct
missions only. Performance can be optimized for specific dates of transfer using gravity
turns but cannot be used in this study because specific missions and dates are not
Simple orbital mechanics defined the 1-body orbit around Earth to a periapsis of
Earth-moon L2 to compute the periapsis deltaV and the atmospheric entry speed of
Finally for all deltaVs in Figure T-2, an additional 5 percent reserve is used.
For vehicle sizing and mass, the Georgia Tech Launch Vehicle and Space System
Synthesis (LVSSS) was used.
This method uses the regression of historical
components of space systems for mass properties and sizes the system to meet thrust-to-
mass ratio and deltaV constraints. A statistical analysis was performed on the vehicle
mass growth history from the initial mass estimate at program start to the final flight
mass showing a growth range from 7 percent for families of similar vehicles to 53
percent for the Apollo lunar module. For this study, the mean of this data, 30 percent,
was used as the growth factor on the estimated inert mass. The LVSSS mass estimate
could be considered conservative because it overestimates the 0.04 inert mass fraction of
the Falcon 9 launch vehicle by 35 percent because of the growth margin and the
utilization of technology that ranges from 4 decades old to today.
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Figure T-2. Transfer Performance DeltaV
Phase 1A — Robotic Scouting, Prospecting, Site Preparation
Paving the Way with Robotics
Prior to establishing a commercially-operated ISRU facility and human arrival,
various robotic systems would be preparing the way. These robotic systems would take
on various tasks and responsibilities to include scouting, prospecting, and initial
infrastructure build-up. As NASA’s Ranger program and Surveyor program led the way
to the manned Apollo program, automated planetary robotic systems will pave the way to
lunar human settlement and resource production plants.
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“The strategy on the Moon is to learn how to mine its resources and build up surface
infrastructure to permit ever increasing scales of operation.”
The Moon: Port of Entry to Cislunar Space, Paul Spudis
Figure T-3. Strategic Approach to Human/Robotic Operations on the Lunar Surface.
Parallel technology development and robotic missions prepare base for human arrival
Scouting is the first stage of resource reconnaissance of a targeted area (second is
prospecting). Initially, precursor robotic surface scouting missions will follow present-
day orbital assets to get a first-hand look at the surface. While lunar orbital data is
important in establishing a large database of information about the lunar surface
(topography, estimate of resources, etc.), it is imperative to get “ground-truth” from
robotic surface systems both for resources, terrain and hazard assessment. Methods
include ground-truth surface mapping and sampling, core drilling, and geochemical
analysis of the water/ice resources. The objectives of this initial phase of operation is to:
1. Identify and prioritize specific sites, through surface operations, that show the
best promise for follow-on prospecting. These robotic assets will search for both
volatiles/water-ice deposits. This step is essential prior to spending time and
energy in prospecting a given site location for water/ice.
2. Identify optimal locations for landing sites and base locations. This would include
reconnaissance of areas best suited for locations of: solar power, landing pads,
habitation, communications and processing equipment for the lunar volatiles.
Initially, five or more robotics surface assets could be combined in a single launch to
‘scout’ likely sites on the Moon’s surface for resources and infrastructure placement. The
robotic assets could be a combination of ‘hoppers’ and ‘lander/rover’ systems. The
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hopper technology allows the robotic scout to cover vast ranges by ‘hopping’ from one
potential resource site to another. On the other hand, the land/rover allow a more detailed
inspection of probable sites.
Figure T-4. Moving from Earth Reliant” to “Earth Independent”. Technology
development required for robotic mobility, drilling and human life support prior
to establishing long-term human operations on the Moon.
While we now know
there is hydrogen, likely in the form of water, in the cold traps
of the lunar polar craters, it is possible that the robotic scouting missions will not discover
a source of hydrogen that enables the economical production of cryogenic (LOX/LH2)
propellant. While we think this unlikely based on the data from multiple sources of
hydrogen at the poles, the consequences would be significant. If this happens, the
proposed strategy for lunar development will need to be amended, and the plans for
prospecting and mining will need to be delayed and potentially cancelled. We have
prioritized this as the number one strategic technical risk among all the identified
technical risks (see “Technical Risk Assessment” on page 28).
The second phase of the robotic reconnaissance is analogous to the mining industry
where key sites are down-selected from the scouting data for more intense resource
prospecting. Prospecting is a much more intensive, organized and targeted form of
scouting. This goal of the exploration phase is to: specifically qualify and quantify the
lunar water/ice….ala “prospecting for gold”. This involves assessing the probable
resource content both in vertical depth at the surface and also horizontally to ascertain
thickness of the ice, physical state and levels of contamination within the water/ice.
Robotic probes would perform chemical analysis on the water/ice. Area selection is a
critical step of the prospecting phase and designed to find the highest quality of resources
(water/ice) as easily, cheaply and quickly as possible. The goal is to define the specific
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strategy to be used in excavating/extracting the water resources at the site, i.e. – what area
of the site is to be extracted first and how is the excavation to expand from the initial
Establish Supporting Infrastructure
Following the prospecting phase, the robotics systems will begin to develop basic site
infrastructure that will transform the site into an ISRU production facility. During Phase
2, the robotic operations will be supported by human sorties to the chosen site.
Paramount to the successful operation is the concept of “living off the land”. Unlike
Apollo, we must learn to robotically manipulate the resources of the surface of the Moon
(asteroids and Mars) by using the indigenous materials located in-situ…without having to
transport materials and supplies from Earth at great expense.
Before ISRU equipment is to arrive, the site must undergo some basic capability
development. A series of site-preparation missions follow to include the arrival of a
100KW solar power and communications infrastructure. This element would be launched
and landed at the site. The robotic systems, further enabled by the newly arrives
power/comm system, would begin constructing the basalt launch/landing pads at the site.
Dust/regolith at the site is a major issue for robotics and site infrastructure. High velocity
lunar dust particles, created by rocket engine exhaust during descent and ascent from the
lunar surface, have the potential to decimate all hardware within line-of-sight. Hence,
robotic systems will perform backblading, leveling operations, and surface stabilization
of the regolith to create launch/landing pads to enable safety and routine transportation
to/from the site. The lunar basalt can be sintered using microwaves to make pavers,
bricks and/or strong sintered surfaces for the landing pads and roads. These robotic
systems will operate autonomously and/or through tele-robotic operations from Earth.
Following the landing pad construction, stabilized roads will be created at the site for
moving ISRU and crew equipment into place once it arrives.
After prospecting, site preparation, and mining excavation, setting up in-situ resource
utilization facility is the next step in the operation. The goal is to robotically install
various equipment necessary to begin water extraction operations. The ISRU facility – a
‘systems-of-systems’ - will perform four major functions:
1. Sorting / Beneficiation
2. Extraction / Reduction
3. Cleanup / Filtering
4. Capture and Storage
Estimates place the projected amount of water on the Moon at 10 billion cubic meters
of water at the poles (equivalent to the Great Salt Lake in Utah). By collecting the
water/ice on the Moon, system processors can separate the water from soils particles and
then separate the remaining water into is elements: hydrogen and oxygen.
The oxygen and hydrogen produced in this ISRU cycle will provide the necessary
consumables for operating fuel cells for the robotic systems, air to breathe, water to drink
and of course…propellant.
This will be a complex operation requiring a period of growth, trial and error, failure,
repair, and maintenance as the process matures in operations and procedures.
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Consumables will be captured in storage containers that handle water, oxygen and
hydrogen. But initially, water can be easily and safely stored. Later, the water can be
separated into cryogenic hydrogen and oxygen. Robotic systems will play a main role of
transferring consumables for propellant transfer for vertical takeoff/vertical landing
(VTVL) systems, storage tanks on rovers for fuel cell supply and more.
Begin Operations - Propellant Tanker/Lander
Once propellant depot operations are underway on the surface of the Moon, a large
reusable Lunar lander/tanker will arrive at the site and land at the previously built landing
pads. Robotic rovers will connect the tanks to the storage facilities to allow the tank
capacity of the lunar lander/tanker to be filled for transport to the depot at L2. The
availability of the large reusable lunar lander, which is 100% refueled from lunar
propellants, is the critical step to a permanent lunar base.
Establish Crew Outpost
Following completion of the ISRU production facility, and the arrival of the large
reusable lunar lander, the site is ready for the delivery of habitats, and other infrastructure
needed for the permanent crewed lunar base. The ELA is designed to launch a Bigelow
BA-330 expandable habitat sized system via either a Falcon Heavy or Vulcan LV to
LEO, which is then transferred from LEO to low-lunar orbit (LLO) by leveraging in-
space propellant transfer in LEO. The large reusable lunar lander will then rendezvous
with the habitat, and other large modules, in LLO and transport them to the surface of the
Moon. These modules would be moved by robotic systems from the designated landing
areas to the crew habitation area selected during the scouting/prospecting operation. The
modules could be positioned into lava tubes, which provide ready-made, natural
protection against radiation and thermal extremes, if discovered at lunar production site.
Otherwise, the robotic systems will move regolith over the modules for protection.
Additionally, the robotic systems will connect the modules to the communications and
power plant at the site.
Human & Robot Interaction as a System:
Why are robotics critical? The reasons that the process begins with robotics instead of
beginning with ‘human-based’ operations like Apollo includes:
1. Robotics offer much lower costs and risk than human operations, where they
effective, which is amplified in remote and hostile environments.
2. Robotic capabilities are rapidly advancing to a point where robotic assets can
satisfactorily prospect for resources and also for set up and prepare initial
infrastructure prior to human-arrival.
3. Robotics can be operated over a long period of time in performing the prospecting
and buildup phases without being constrained by human consumables on the
surface (food, water, air, CO2 scrubbing, etc.).
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4. Robotics can not only be used to establish initial infrastructure prior to crew
arrival, preparing the way for subsequent human operations, but to also repair and
maintain infrastructure, and operate equipment after humans arrive.
Why do robots need humans to effectively operate a lunar base? Why can’t robotics
“do it all”? Why do we even need to involve humans in this effort?
1. Some more complex tasks are better performed jointly by humans and
robotics….or by humans themselves. This is an important area of research and
2. Humans operate more effectively and quicker than robotic systems, and are much
more flexible. Human are able to make better informed and timely judgments and
decisions than robotic operations, and can flexibly adapt to uncertainty and new
3. Robotic technology has not reached a point where robots can repair and maintain
themselves. The robotic systems will need to periodic as well as unscheduled
maintenance and repair….provided by humans.
Public Benefits of Investments in Advanced Robotics
U.S. government investments in advanced technologies such as robotics will have
tremendous impacts on American economic growth and innovation here on Earth. The
investments just by DARPA in robotic technologies are having significant spill-over
effects into many terrestrial applications and dual-use technologies. Examples of dual-
use technologies include:
a. Robotic systems performing connect /disconnect operations of umbilicals for
fluid/propellant loading … could lead to automated refueling of aircraft, cars,
launch vehicles, etc.
b. Robotic civil engineering: 3D printing of structures on the Moon with plumbing
through industrial 3D printer robotics, could lead to similar automated
construction methods here on Earth.
c. Tunnel inspections: Robotic operations for inspecting lava tunes on the Moon
could lead to advanced automation in mine shafts on Earth. Advances in
autonomous navigation, imagery, and operations for dangerous locations and
places could save many lives here on Earth.
d. Remote and intelligent inspection of unsafe structures from natural disasters
(tsunamis, radiation leakage, floods, hurricanes) could enable many more
operations by autonomous robotics where it is unsafe to send humans.
The following roadmap outlines the program development and operations: (dates are
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Lunar lander demonstration
DDTE of scouting / prospecting technologies for the landers
Deployment in phased sorties for scouting operations
Launch and deployment of robotic prospecting assets
DDTE on Earth of ISRU capability
Site selection for ISRU operations and base plant, including “Go/No-Go”
decision for production of flight systems for lunar ISRU propellant systems.
Begin robotic construction phase for launch/landing pads, power systems and
infrastructure at chosen lunar site
Human Lunar Landing at Equator
Robotic setup and testing of ISRU demo operations at selected test site
Begin testing of integrated ISRU production systems on Moon
Initial polar facility (propellant production) operations
Phase 1B — Human Sorties to Lunar Equator
For lunar sorties, the ELA
system architecture has many
similarities to the Apollo
architecture, but is somewhat
different because we use existing
space systems, infrastructure and
technologies. For Apollo, Earth
orbit was achieved with the very
large Saturn V launch vehicle to
deliver all the lunar system
architecture to orbit in one launch.
The Saturn third stage (S-IVB)
performed a suborbital burn to
low-Earth Orbit (LEO), and also had enough propellant to perform a second burn
TransLunar Injection (TLI) burn. As the system approached the moon, the Service
Module performed the Orbit Insertion (LOI) burn. The astronauts transferred from the
astronaut habitat Command Module capsule
to the 2-stage Lunar Module for descent to
and ascent from the lunar surface. After the
sortie missions, later including the Lunar
Rover for surface transportation, the crew
performed a Lunar Orbit Rendezvous of the
Lunar Ascent Module with the
Command/Service Module in lunar orbit.
For return to Earth, the Service Module
performed the TransEarth Injection (TEI)
burn; the Command module separated,
entered the Earth’s atmosphere and splashed down in the Pacific for recovery.
Today, there are several options for space system elements of repeating lunar sorties;
however, today’s smaller commercially available launch vehicles required more than one
launch to low-Earth orbit and element assembly before continuing to the moon. The
Figure T-6. Apollo System Elements
Figure T-5. Apollo System Architecture
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following analysis is focused only on SpaceX space systems, which is only one of many
options available today; this selection is solely based on the availability of open source
data for system performance, mass, cost, and technology.
It should be noted that the United Launch Alliance (ULA) released on April 2015
their technology roadmap for advanced programs that includes a distributed space system
architecture for supporting cis-lunar, lunar, and deep space mission. This architecture has
a next generation launch system, called Vulcan, doubles the payload capability of the
Atlas V can be fitted with 6 solid rocket motors and an advanced cryogenic evolved stage
(ACES) with a GTO payload of 32t. The Vulcan uses the Sensible Modular Autonomous
Return Technology (SMART) to return the new low-cost BE-4 engines and avionic
package. In addition, low-cost/fully reusable XCOR engines will replace six-decade old
RL10 engines for in-space propulsion and upgrades to the Boeing CST-100 for cargo and
human transport. This new capability is projected to be price competitive with SpaceX.
In addition, ULA has conducted experiments at NASA Marshall for cryogenic fluid
transfer and advanced fluid management systems for utilizing any boiloff propellant for
stationkeeping. Also, ULA has complete design of the dual thrust axis lunar lander using
the Centaur/Delta IV upper stages and ACES for reliability and again low cost.
this study that ends in Phase 3 using LOX/LH2 produced for the lunar surface, this new
architecture would eliminate technology development costs of fully reusable LOX/LH2
engines and development costs of the Lunar Module. Unfortunately, the ULA
announcement was too late to be incorporated into the first phase of this study.
Launch Vehicle and TransLunar Injection/Lunar Orbit Insertion. Historically,
the human mission cost beyond Earth’s orbit have been dominated by launch cost.
However, the cost reduction revolution started by SpaceX with their Falcon launch
vehicles and being matched by ULA’s Vulcan launch vehicle development will usher in a
new era for human exploration. Launch cost is dramatically being reduced and may
become a fraction of the mission cost rather than the dominating cost factor. For this
study, the Falcon 9 and Falcon Heavy were used as representative of the new trend in
launch costs because of the violable prices on the SpaceX web site.
SpaceX currently operates the Falcon 9 that has a payload of 13.1t to LEO at 28.5° at
a per launch cost of $62.1M ($4750/kg) as per there Web site. This compares to the
Saturn V that delivered 130t at $46,000/kg. The economy of Falcon 9 is based on the
large number of planned launches per year; as of 2016 there are 21 launches currently
sold. In addition, SpaceX is actively developing a reusable Falcon 9 that should further
In addition, SpaceX is developing the Falcon Heavy using 3 modified Falcon 9 cores
and the Falcon 9 second stage. Falcon Heavy has an advertised payload to LEO of 53t at
a cost of $90M ($1700/kg). Because of the lack of maximum payload (53t) compared to
the Saturn (120t), multiple launches of the Falcon Heavy (and Falcon 9s) are required for
the lunar sortie as shown in Figure T-7. As will be shown in the Life Cycle Cost section,
this is an excellent economical approach because the price of the Falcon Heavy and
Falcon 9 launches on a dollars per kilogram basis are more than an order of magnitude
lower cost than the Saturn V and Space Shuttle programs.
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Figure T-7. Phase 1 Lunar Sortie
For this mission, the Falcon Heavy 2
Stage is modified by extending the propellant
tanks to deliver propellant in its tanks for the TransLunar Injection and Lunar Orbit
Insertion (equatorial TLI=3,268 m/s and LOI=949m/s which includes a 5% margin). The
mass of the tank barrel section extensions for the left over propellant is 586kg for the
LOX tank and 366kg for the RP tank which is less than the 2500kg fairing. Thus, the
stage can deliver 53.6t of propellant to orbit, slightly more than its stated
payload of 53t. This tank extension is not a costly modification because all the Falcon
stages are 3.66m in diameter and use the same manufacturing rig. In Phase 1, two
Stages are mated in orbit and can deliver 35.9t to low-lunar orbit, more than
the required 24.6t Dragon V2.
Command/Service Module: The Command
Module/Service Module is a modification of the
SpaceX Dragon V2 spacecraft designed for
delivery of 7 astronauts to the space station (see
Figure T-4). Its dry mass is 6.4t with a cargo
capacity of 3.3t for a total of 9.7t plus 1,456kg for
deorbit and landing. As opposed to using
hydrogen fuel cells for power, the Dragon V2 uses
solar cells deployed from the first trunk as shown
in Figure T-8. In this study, the Dragon V2 was
modified for 4 astronauts for up to 14 total days (8
to and from the moon with 6 day margin) for a
total mass of 11t (plus 1.2 factor for ASE). In addition, a second trunk was added to the
Dragon V2 to provide an additional 10,625kg of propellant for the TransEarth Injection
Figure T-8. Modified Dragon V2
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(equatorial 1,061m/s). The total trunk mass was 12,752kg. It should be noted that the
Phase 1 architecture only supported an equatorial mission with 2 astronauts on a 7 day
sortie. However, with additional translunar mass payload capability in Phase 3, the
modified Dragon V2 has the capability to support a crew of 4 to the lunar poles and the
propellant for the transEarth injection.
The Super Draco engine uses hypergolic propellant (NTO-MMH) with a thrust of
68,169N at an estimated specific impulse of 324s vacuum.
Lunar Module: For Phase 1 minimum sorties, the lunar module is initially operated
only for 2 crew for a 7-day mission to gain early experience with the new systems. As
shown in Figure T-9, the lunar module was designed with the Super Draco engine and the
life support from the Dragon V2. Although not shown, 2.1kW of power is provided by
Ultraflex solar arrays rather than the 72hr batteries of Apollo. A straight descent to the
lunar surface is planned differing from the Apollo lander where the astronauts were given
time to seek an appropriate landing site while descending. Thus the ascent and descent
deltaVs are 1,988m/s (includes 5 percent performance margin). Unlike Apollo, the use of
a polar-capable design for early equatorial missions allows a significantly higher
consumables margin for these early missions. Although the missions were very similar,
the current Lunar Module has a total mass greater than Apollo module where new
technology is offset by additional required design and performance margins.
Figure T-9. Lunar Module Comparisons
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Technology: During Phase 1, technology will be developed to meet the requirements
of an eventual permanent human outpost tending the lunar ice propellant plant.
First a more efficient TransEarth Injection Stage will need to be developed. Because
Stage is delivered to orbit with tanks that are 73 Percent empty (the tanks can
accommodate 143t more propellant), technology will need to be developed to transfer
and store in orbit for extended duration both LOX and RP in orbit. This TransLunar
Injection Stage (modified Falcon 9 2
stage) can be adjusted to a range of
payload from 15t to 70t by the amount
of refill propellant in orbit. Thus, the
cheapest "payload to orbit" launch
vehicle can be used such as a reusable
Falcon 9 or any other new launch
vehicle. As shown in Figure T-10, the
amount of refill propellant can be
adjusted to meet the payload needs.
Thus, 2 Falcon 9 refills (24t) can be
used to put 23t of payload to lunar
orbit, which is more than needed for the
The second critical technology is to develop highly reliable and supportable life
support, communications, power, data, mobility, and other subsystems for the permanent
human outposts. Reliability, failure data, and spares for the space station will inform the
requirements for each of the critical systems. However, for the ISS, maintainability
optimization was to minimize crew time for maintenance, while mass for spares was not
as constrained due to the relative close proximity to Earth. Reduction of spares mass will
be needed for cost-effective lunar operations. Requirements for spares to be transported
to the outpost will be based on reliability improvements and a supportability concept that
is optimized for lunar rather than LEO operations.
Finally, the technology for ISRU LOX/LH2 production needs to be developed ending
with a demonstration on the lunar pole in Phase 2. Included in the technology
development and demonstration are excavators and loaders for mining the regolith,
haulers for moving the regolith, hoppers for feed, extraction of water from regolith,
electrolysis and liquefiers for oxygen and hydrogen production, and storage for water and
zero-boiloff propellants, and the power for the plant either solar electric or nuclear.
Phase 2 — Human Sorties to Poles
Phase the base of operations is moved from the lunar equator to the lunar poles
to determine the best location for extracting lunar ice found in the robotic searches in
Phase 1 and then operate a pilot production plant. The pilot plant has a maximum mass
of 7.4t to support requirements to incrementally build up capacity using a modular
approach as described in the Risk section and because this is the payload of the Lunar
Descent Module is also sized to support this strategy.
As shown in Figure T-11, the system architecture is similar to Phase 1. However,
with on-orbit refill technology, only a single Falcon 2
Stage is required to reach the
Figure T-10. Payload to Lunar Orbit from refilling
the Falcon 2nd Stage
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poles instead of 2 reducing the risk of assembly of the stages and staging. Shown in the
figure are multiple reusable Falcon 9’s for refilling the stage assuming that they will be
the cheapest payload delivery launch vehicle. However with refill, the cheapest existing
launch vehicle at that time is likely to be used to further reduce cost. In addition, a
propellant depot could be used to accept propellant from any supplier, and would separate
the multiple refills to the mission stage to just one to simplify operations. As shown for
the Dragon V2 delivery, only 14t additional propellant is required for lunar transport but
2 Falcon 9Rs are used with a total capacity of 25t of propellant. Thus one of the launches
has only a partial payload with propellant. While a depot would ensure that all flights
Figure T-11. Phase 2 System Architecture
had a full payload of propellant and might be justified on economics or for operational
reasons, we assumed direct propellant transfers from the launcher to the TLI stage.
Phase 2 continues lunar transport operations and testing of LOX/LH2 ISRU
propellant plant systems at the lunar poles. In parallel, technology development continues
to develop the technology for Phase 3.
Technology: Phase 2 technology developments support the DDT&E of the ISRU
production plant and the delivery system of the propellant to L2 for the Mars Transfer
Vehicle in Phase 3. High risk developments include a highly reliable, supportable, and
efficient ISRU system, reusable LOX/LH2 rockets to deliver the propellant to L2 and
return to the lunar surface. Other medium risk technology developments include a
cryocooler system for zero boil-off on the lunar surface and at L2, in-space storage and
transfer of LH2 (LOX was demonstrated in Phase 1), lunar human and cargo rovers for
ISRU operations, a large highly reliable human outpost for 4 crew.
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Phase 3 — Propellant Delivery to L2 & Permanent Lunar Base
The Phase 3 system architecture is shown in Figure T-12. Transportation to the moon
still assumes use of the Falcon Heavy with the 2
stage refilled with Falcon 9Rs. The
key differences are in the operation of the LOX/LH2 ISRU production plant and the
transport of the propellant to a depot in L2 with a reusable LOX/LH2 Lunar module.
Figure T-12. Phase 3 System Architecture
Reusable Lunar Module (RLM). The RLM is designed to deliver the propellant to
L2 and return. In addition, the RLM replaces the Phase 1 Lunar Module and delivers
from low-lunar orbit to the surface the following: the ISRU plant, human and cargo lunar
rovers, All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHELETE) for lifting and
moving cargo, the large 4-crew habitat, and as well as crew as seen in Figure T-13. This
is based on a NASA-designed lunar base buildup scenario.
The RLM has reusable LOX/LH2 engines with
performance similar to the RL10B-2 with a specific
impulse of 465s. The RLM was designed for a low-
lunar orbit to surface payload of 24.3t capturing the
ISRU plant of 22t and the habitat of 20t. For propellant
delivery to L2, 13 flights per year are required for the
assumed LOX/LH2 Mars Transfer Vehicle with a
propellant payload of 12.2t and tanks and airborne
Figure T-13. Representative
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support equipment of 10 and 20 percent respectively. The RLM has an inert mass of 8.3t
and propellant mass of 47t giving a propellant mass fraction of 0.90.
LOX/LH2 ISRU Plant. The ISRU plant was designed to produce LOX/LH2 for the
LOX/LH2 Mars transfer Vehicle based on NASA’s DRA 5.0 Mars Architecture.
architecture supported two 103t cargo flights followed 26 months later by a 62.8t payload
crew flight. A two-stage Mars Transfer Vehicle was conceptually designed using the
same reusable LOX/LH2 engines as the RLM and a propellant mass fraction of 0.9 (same
as the Saturn S-IVB). The total propellant required for each mission was 158t where the
103t cargo flights were one way to Mars and the crewed flight was round trip to L2. The
Mars cargo payload is delivered to L2 in two increments and the crewed payload in one
The RLM was designed to transport
the propellant to L2 requiring 38t per
flight and 13 flights per year. Thus the
ISRU plant is designed to produce
propellant for the RLM as well as the
MTV propellant totaling 707t per year.
Using a 10 percent margin, the ISRU
plant was designed to produce 777t per
year. Modularization of the ISRU
systems to allow delivery and operation
in increments is planned to allow initial
production at 1/3 of total planned
capacity with growth to full capacity in
two additional increments. This allows
for learning between increments to be
implemented in the ISRU design,
operation at partial capacity in the event
part of the system is down for
maintenance, and provides for future
growth if needed.
The ISRU model is similar to results presented in the Lunar Surface Construction &
Assembly Equipment Study in 1988
. It is assumed that the lunar pole regolith is 1%
water ice being conservative of 1.4% from Chandrayann-1 and 5.6% from Lunar
Reconnaissance Orbiter. The model consists of front loader, hauler, low and high-
pressure hoppers, electrolysis, oxygen and hydrogen liquefiers and tanks, and power.
The ISRU components and total mass are shown in Figure T-14. A nuclear power plant
is assumed; however, with the plant at the poles, solar arrays could be used and the ISRU
plant could be delivered in two trips.
Habitat. The largest payload for the RLM is the Bigelow 330 inflatable space habitat.
It has a mass of 20t and a 330 m3 volume (13.5 m long by 6.7 m diameter). It is designed
to have two solar arrays and thermal radiators and life support systems to support a crew
Outpost Infrastructure. The pressurized crewed and cargo rovers were taken from
the MARS DRA 5.0 study with masses of 9.6t and 0.5t.
Ice Concentration 1.00%
Annual Propellant Demanded 777,000 kg
Water (3.52kg/day; 4-crew; 20% margin) 6,167 kg
Oxygen (0.84kg/day; 4-Crew; 20% margin) 1,472 kg
Front Loader 1,078 kg
Hauler 889 kg
Low Pressure Feed Hopper 13 kg
High Pressure Feed Hopper 88 kg
Regotith Thermal Processing 561 kg
Electrolysis 2,728 kg
Oxygen Liquefier 1,559 kg
Hydrogen Liquefier 566 kg
Water Tank 234 kg
Oxygen Tank 935 kg
Hydrogen Tank 2,306 kg
Nuclear Power System (SNAP-50 alpha) 10,764 kg
Total ISRU Plant 21,721 kg
Figure T-14. ISRU Production Plant
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For lifting and moving large components like the ISRU plant and habitat, the JPL
ATHLETE was selected. Based on analysis by Brian Wilcox of NASA JPL,
ATHLETE was sized for the lunar surface carrying a 25t payload resulting in a total mass
of 4.8t including a 30% mass margin.
L2 Propellant Depot. The LOX/LH2 L2 propellant depot was selected from
previous analysis on propellant depots
for the required propellant mass storage of 230t.
The depot has an empty mass of 18.2t thus in the same payload class of the IRU plant and
habitat. The depot is designed for zero boiloff with a cryocooler system mass of 2.2t
requiring a power of 2.6kW that was designed by Dr. David Chato at NASA Glenn. The
depot has propulsion for station keeping at the Earth-moon Lagrange points (EML1 and
EML2) that require 50m/s of deltaV.
Phase 4+ (Optional) — Reusable OTV between LEO and L2
One of the major remaining cost drivers in Phase 3 is the transport of payloads from
LEO to lunar orbit. This is a significant cost of permanent lunar operations, as well as
the delivery of the Mars payload from low-Earth orbit to L2 for integration on the Mars
Transfer Vehicle. One potential next evolution in the ELA is the development of a
reusable Orbital Transfer Vehicle (ROTV) that is optimized for transporting large
payloads between LEO and lunar orbit. This OTV could be refueled either in LEO or
from the Moon.
In NASA’s Mars DRA 5.0 study
, one complete mission requires three trips to
Mars. The first two trips deliver the required 103t of payload for each cargo delivery and
the third trip, taking place 26 months later, delivers the crew to Mars. The cargo mainly
includes the aerobreak shell (2x43.7t), descent stage (2x23.3t), surface habitat (16.5t),
nuclear power (7.3t), ascent stages (21.5t w/RP propellant), ISRU plant (1.3t), rovers and
power (10.6), crew consumables (6t) and miscellaneous smaller items. The crew system
consists of the transit habitat (32.8t) and a backup Command Module (13.2t, Dragon V2x
in this study).
The initial transfer to L2 of the Mars cargo uses the expendable filled Falcon 2
for transfer requiring the delivery of the stage and one-way propellant requiring 8 Falcon
9Rs or 2 Falcon Heavys.
We specifically studied the concept of an ROTV that is filled with lunar LOX/LH2 at
L2 and completes a TEI burn with no payload and a trans-L2 injection burn with payload.
To maintain a reasonable size for the ROTV, a payload of 27t was selected (one-quarter
of each cargo payload mass). For an ROTV that uses propulsion for the entire round trip,
the performance requirement is 6,967 m/s (deltaV= 3,692 m/s for TransL2 Injection and
L2 Insertion, 49m/s TransEarth Injection, and 3,226 m/s for Earth Orbit Insertion). The
resulting ROTV vehicle has a gross mass of 229t with
an inert mass of 34t and propellant mass of 194t per trip.
However, if Earth aerocapture is employed (Figure
T-15), the performance requirement is reduced to 4,041
m/s (deltaV= 3,692 m/s for TransL2 Injection and L2
Insertion, 49m/s TransEarth Injection, and 300 m/s
Earth orbit correction). The analysis assumed the same
ballistic coefficient as the Apollo Command Module
(capsule) and the same structural and thermal protection
system fraction. A 20 percent mass savings can be
Figure T-15. Aerocapture
Reusable OTV Module
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obtained using the SpaceX Dragon heatshield with composite load bearing structure and
modern PICA thermal protection material. The resulting ROTV has a gross mass of 154t,
with inert mass of 48t (including the 34t aeroshield), and propellant mass of 106t.
With the aerocapture ROTV, a reusable heatshield has to be developed to eliminate
the need to deliver a heatshield to L2 for each roundtrip. Options include a larger area
(lower ballistic coefficient) to reduce heating for a non-ablative heatshield possibly using
an inflatable concept or use the “free” lunar water for transpiration cooling to further
reduce the surface heating.
The resulting impact on the system architecture is an additional same-size ISRU plant
and an additional Reusable Lunar Module for delivering the propellant to the ROTV.
Technical Risk Assessment
The main technical risks of the system architecture are the following:
ISRU Processing & Exploitable Lunar Ice (High)
Reliable LOX/LH2 ISRU system (High)
Long Life (100+ uses) Cryo Rockets (High)
LOX/LH2 Storage and Orbit Transfer (Med)
Long Life (years) Commercial Habitats (Med)
Long Duration Dragon V2.1/CST-200 w/prop (Low)
The most significant system-level technical risk of the ELA is
the possibility we will not find abundant enough levels of
accessible hydrogen, which is critical to enabling economical
production of lunar propellant.
The most significant system-level technical risk of the entire ELA is the possibility
we will not find abundant enough levels of accessible hydrogen, which is critical to
enabling economical production of lunar propellant. While we have proven that there is
hydrogen trapped in lunar polar craters, we do not know how deep the water/hydrogen is
buried, or if it is locked up in some form that is uneconomical to release. To mitigate this
risk, rovers and prospecting systems need to be developed, tested, demonstrated, and
validated. The availability of readily and economically available water, or hydrogen, at
the lunar poles needs to be proven before significant investments can be made in all the
other ISRU systems and the reusable lunar module that depends on lunar propellant. To
the extent national decision-makers value the economical production of propellant at the
lunar poles, this objective needs to be a top priority.
Next, although the physics of harvesting and processing lunar ice into water and
liquid oxygen and hydrogen are well known, a key technology to develop is an extremely
reliable and autonomous system for mining the water/hydrogen. While these systems
must be designed to be reliable and autonomous, they must also be remotely repaired by
robots and/or humans on the surface of the Moon. The primary economic purpose of
humans of the Moon is repairing and maintaining the autonomous systems. Just as we at
ISS, but even more so, astronaut time is going to be the most rare and precious resource.
Spares and line replace units are planned, but a constant transfer of ISRU subsystems or
complete systems from Earth would destroy the economics of propellant supply. Related
NexGen Space LLC Page 29 Evolvable Lunar Architecture
to this, the ability to rapidly manufacture replacement parts on the Moon using local
materials and additive manufacturing will be a critical technology.
The final high-risk technology is long-life cryogenic rocket engines for the Earth-
moon and moon-L2 transfer modules. In the Phase 3 operational scenario, every year
there are six trips from LEO to the moon for crew and cargo delivery, plus 13 trips from
the surface of the moon to L2 for propellant delivery. A fully reusable lunar landing
system is mandatory in this architecture, with the primary technical challenge being
highly-reliable and reusable cryogenic rocket engines.
The cryogenic propellant storage and orbit transfer is rated at a medium risk.
Propellant transfer has been shown to be viable through the many Russian Progress,
Automated Transfer Vehicle (ATV)/space station and the DARPA Orbital Express
demonstration. But these propellants are storables; with cryogenics the key areas of
concern are no-leak connectors and low-boiloff transfer. The transfer may be completed
by mechanical means, circular momentum, or by low-g fluid settling.
For zero boiloff, there are existing Earth-based cryocoolers such as the Cryomech
Gifford-McMahon Cryorefrigerator that has the capacity and size required for the ISRU
plant and propellant depot. The AL325 requires only 11.2 kW of power, weighs 22 kg,
small volume (122 x 102 x 150 cm) and costs $43k. Technology development requires
changing the cooling liquid from water and 0-g operation. The other medium risk
technology is long-life human habitats. The key is to reduce maintenance and spares to
enable economical long-life operations.
NexGen Space LLC Page 30 Evolvable Lunar Architecture
Life Cycle Cost Estimates
NexGen’s life cycle cost (LCC) analysis of the evolvable lunar architecture (ELA)
addresses key factors beyond the cost of the elements (launchers, landers, spacecraft, etc.)
These factors include: (1) modeling and uncertainty, (2) a NASA budget context, and (3)
integrating innovative ways of doing business. This economic assessment of the ELA,
devised using public-private partnerships to create an affordable and sustainable
approach, used a combination of system engineering, economic modeling and analysis,
and a NASA budget context to assess life cycle alternatives.
The maturity and value of an estimate in making decisions among various options
depends on certain factors. These include a clear purpose to the estimate, the expertise of
the estimators, the availability of suitable historical data, and understanding uncertainties.
NexGen’s team included subject matter experts (Wilhite and Zapata) with over six
decades of experience in space systems cost estimation and economic modeling, and
leveraged access to many decades of historical cost data, including relatively new data
about the cost efficiencies of commercial partnerships.
Basis of Estimate
NexGen’s LCC estimates for the ELA reduced traditional cost estimation models
over-emphasis on weight-based cost estimation — which loses significant context in the
data. We focused on the development of an integrated, comprehensive LCC
(development, manufacturing, flight and ground operations, procurement and
government), all within a proper NASA budget context, and incorporated non-technical
acquisition approaches alongside traditional technical/design factors.
For this Basis of Estimate (BOE), the LCC model applied estimates of all life cycle
costs consistent with NASA budget practice. For the ELA assessment, we included:
• Non-recurring and recurring costs
• Development, manufacturing, ground operations & launch costs, and
• Direct and indirect costs:
o Industry / procurement (contractor, partner, support contractors, and related)
o Government (civil servants, government management and related)
– Program Management (i.e., Level 1 NASA at HQ, etc.)
– Project Management (i.e., Level 2/3 NASA at centers, by element, etc.)
As described in the Study Assumptions (see page 6), the NASA budget into which the
ELA cost estimates must be phased is limited to slightly less than $3B per year. This is
the amount below the blue-dashed-line in Figure LCC-1.
NexGen Space LLC Page 31 Evolvable Lunar Architecture
Figure LCC-1. The NASA Human Exploration & Operations budget splits.
Additional ground rules for the ELA include:
• Address the concurrence of the architecture with other NASA projects and
elements (e.g., cargo/crew to ISS) and any cost effects, such as using these
available elements or elements derived from these.
• Use year 2017 as year 1 / Authority to Proceed.
• Target 2 crew flights per year to lunar surface locations.
– Cargo support flights linked.
Given the importance of assumptions to a cost estimate, NexGen’s analysis made
assumptions across all major Human Exploration & Operations budget items. The most
significant of NexGen’s assumptions include:
• Assume the ISS is operational concurrent with the architecture
– ISS R&D, cargo transport to ISS, and crew transport to ISS continues. ISS
funding is generally not available for other purposes throughout the life of
– Exception: ISS Operations as ~ equivalent to Mission Operations (see
– Exception: Lunar architecture possibly indirectly reducing costs of cargo
& crew missions to ISS, and/or to a post-202x (TBD) ISS end-state or ISS
– Most Human Spaceflight areas not affected – Mission Operations, AES,
SFS, Space Technology
#"() #"(* #"(+ #"#( #"#, #"#) #"#* #"#+ #",( #",, #",) #",*
Human Exploration & Operations Total
(excluding CAS / CMO & STMD)
ISS Crew & Commercial Cargo, Commercial Crew, & R&D
Exploration (incl. KSC Ground Ops / Launch)
~$2.8B/year Procurement & Gov’t
NexGen Space LLC Page 32 Evolvable Lunar Architecture
– Exception: Additional capabilities & costs due to certain in-space
operations to be addressed separately (“Other In-space Operations”).
– Exception: Address potential NASA Spacecraft Communications and
Network (SCaN) budget shortfalls, whereby existing capabilities may be
adequate to support cis-lunar operations, but using these capabilities
would incur costs.
• Additional SCaN capabilities offer new opportunities via a NASA
• Assume NASA budget growth vs. aerospace cost inflation factors – per assorted
scenarios (NASA inflation index, usual OMB or agency guidance, etc. or other
scenarios; some scenarios lose purchasing power over time)
• Assume NASA Civil Service levels persist. No ability to convert any government
program/project management savings into procurement / partner $.
• According to the Acquisition Entity, assume effects on prices consistent with
prior experience applies – key consideration affecting prices from providers /
partners (prices = costs to NASA)
– Phase 1 NASA acquisition approach is analogous to the Commercial
Orbital Transportation Services / Cargo Resupply Services (COTS/CRS)
development & acquisition partnerships
– Phase 2 & 3 NASA acquisition approach is a series of development &
acquisition partnerships with a “Lunar Authority” analogous entity
• Other customers / business case impacts
– Integrate the amortization effect of the Acquisition Entity procuring
elements that are also common with other non-NASA customers or
business cases (unit volume dependency, etc.)
– Investment business cases
– The effect of a providing partner investing X % private capital in
development that is not recovered by the partner until later in recurring
operations (smoothen phasing).
While ground rules and assumptions (GR&A) set the stage for a cost estimate,
historical data provides a foundation. NexGen’s estimate of the ELA’s LCC required
estimates of elements from spacecraft to launchers to unique space systems, including
related operations, atop which would rest any government program and project
Given that many ELA space system elements are cargo or crew spacecraft of some
type, and given that this study’s purpose was to explore public-private partnerships,
recent hard data from partnerships that are developing cargo and crew spacecraft was
preferred in developing cost estimates. Figures LCC-2 and Figure LCC-3 show data
across a range of spacecraft, from (1) space to surface, from (2) much older to very recent
programs, from (3) cargo to crew applications, and from (4) cost-plus ownership to
commercial partnership acquisitions.
NexGen Space LLC Page 33 Evolvable Lunar Architecture
Figure LCC-2. NASA NRC development costs of spacecraft, procurement only, assorted
Figure LCC-3. NASA RC price per unit, costs of spacecraft, procurement only, assorted
For launch services, recent NASA contract price data was preferred for estimating the
costs of acquiring launch services in the ELA. The launch price (specifically, the price to
NASA) can be characterized not just according to class of payload, but also according to
block purchases of launches. The ISS, through the ISS Space Transportation Office, or
the Commercial Crew Office has made bulk multi-year purchases, vs. purchases of just
one launch through the Launch Services Program (LSP). Where data was not available,
the cost estimate used a cost estimating relationship consistent with the extent of what
data was available. For example, NASA has procured Falcon 9 launchers as block-buys
(within ISS cargo and crew services) and as one only (for science missions). The cost
NexGen Space LLC Page 34 Evolvable Lunar Architecture
estimating applied additional costs and premiums for NASA acquiring the services of a
Falcon Heavy fully consistent with Falcon 9 acquisition data.
Ground and mission operations are additional costs beyond the cost of acquiring
spacecraft and launch systems. According to the scenario, cost-estimating relationships
applied consistent with both historical data (usually the upper bound) and the partnership
approach (the lower bound).
To be conservative, the estimate calculated government program and project
management across all phases and elements of the ELA at traditional levels. These
estimates may be extremely high and inconsistent with a partnership approach, but
consistent with the NASA budget whereby any savings here do not easily convert into
additional procurement dollars. The conservative approach was preferred, consistent with
the NASA budget, if not the partnership approach.
Lastly, for estimating the cost of unique items, for example a propellant depot, the
process relied on a combination of past studies, subject matter experts and conservatism
again applied atop any values.
To address uncertainty at steps along the basis of estimate, the process created a
three-point estimate across any points of departure as well as within adjustments and
extrapolations. This is consistent with the level of assessment of this study, as an
“architecture” or concept level LCC profile.
Modeling & Analysis - Scope
Figure LCC-4 summarizes what is included in a cost estimate, the “itemized bill”, and
what is not, and what is addressed in some way other than being included as a cost
estimate (an assumption for example).
Figure LCC-4. Scope of the LCC of the ELA.
• Landers for Prospectors
• LO/RP Storage/Transfer Demo
• ALL Launchers for Prior
• ISRU Demo (6.5t) Development
• Mods of 2
• Mods of LEO spacecraft to Cis-
• Crewed Lunar Lander Development
(Expendable, 2 Partners)
• Test Flight Unit Items
– Prior Spacecraft
– Prior Lunar Landers
– Launchers for Prior
• Crew Spacecraft
• Launchers for Prior
• In-space Ops (see FAQ)
• Carrier Tanks Development
• Mod of 2
Stages, to Fillable
• Launchers for Test Flights of
• Launcher for ISRU Demo (from
• LH2 storage Transfer Demo,
• Carrier Tanks
• Crew Spacecraft
• Crew Landers
• Launchers for Prior
• In-space Ops (see FAQ)
• Crewed Lunar Lander Development (Reusable, 2 Partners)
– + 1
• ISRU Plant Development (Full Scale)
• LLO Refueling Station Development
• Rovers Development + 2 Units
• Equipment Development (“ATHLETES”) + 2 Units
• Habitat Development + 2 Units
• Launchers for Prior (per Ph. 2, 2
• Carrier Tanks for Prior Launchers
• Cargo / Canisters (& Lander / Descent Portion)
• Launchers for Prior
• Crew Spacecraft
• Launchers for Prior (per Ph. 2, 2
• Carrier Tanks for Prior Launchers
• Crew Use / Ops of Lander (Reused)
• In-space Ops, +More Surface Ops of Prior
• Continuous Replacement Costs - Life Limited Items
(Reusable Lander, ISRU Plant, etc.)
+ $ Across All Phases > Government Program Management, Project Management, KSC Ground Ops
+ What $ are elsewhere @ existing NASA budget levels > Space Flight Support (incl. SCaN, LSP), JSC Mission Control & Ops (see
FAQ), and R&D & Technology (AES, STMD)
NexGen Space LLC Page 35 Evolvable Lunar Architecture
Modeling & Analysis – Drivers
Some of the cost drivers of particular interest in the ELA are primarily non-technical.
• Phase 1 operates under a COTS/CRS acquisition model
– Assume slightly more efficient than Commercial Crew acquisition model
– Crew Spacecraft - some reusability (crew module portion)
– Launchers - expendable
– Lunar landers – new / expendable
• Two developments as w. commercial partnership acquisitions; with
two providers, for dissimilar redundancy and competition.
• Phase 2 & 3
– “Lunar Authority” partnership / acquisition model improves prices (costs)
to NASA over Phase 1
– Launchers - some reusability
• Phase 3
– Lunar lander – new / reusable (additional in-space ops, etc.); two as before
for dissimilar redundancy and competition.
– Rovers, equipment, habitats
– Additional replacement costs of life limited items
• Esp. ISRU facility, landers, and L2 refueling station, rovers, etc.
Modeling & Analysis – Context, the NASA Budget
The basis of estimate receives its context from within NASA budget scenarios based
on hard empirical data. We assumed a budget increase based on the average budget
growth of NASA’s budget over the last 13 years (at 1.175% per year), and assume this
will be exceeded by the level of cost inflation in the system (estimated at 2.5% per year,
per the official NASA Inflation Index). This conservative baseline scenario assumption
reduces the purchase power available to NASA over time. Figure LCC-5 shows NASA
budget data since 2003, arranged to show a flow of funds of like items. For example,
Shuttle “operations” (red) segue into Commercial Cargo and Crew –again “operations”.
This data shows that NASA’s actual top line budget has grown by 1.175% per year, but
NASA’s real purchasing power has decreased because of inflation.
NexGen Space LLC Page 36 Evolvable Lunar Architecture
Figure LCC-5. The NASA budget since 2003. All data from public NASA budget documents,
“actuals” 2003 to 2013. 2014 and 2015 from public documents estimating costs (actuals pending).
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
<# US!Commercial Crew!ISS!# Boeing!&!SpaceX #>
<## ISS!Cargo!(US Commercial,!Antares!&!Falcon!9 Launch,!
NexGen Space LLC Page 37 Evolvable Lunar Architecture
Life Cycle Cost Assessment - Results
The assessment placed the component costs of elements of the lunar architecture in a
schedule, with development leading to manufacturing and operations, and later phases
overlapping a prior phase of operation. The study goal was to remain (roughly) below a
yearly budget constraint and above a certain flight rate tempo. The baseline case shown
in Figure LCC-6 has the following characteristics:
• Partnerships Driven
-NASA COTS/CRS-like acquisition drives Phase 1
-NASA Partnership with a Lunar Authority drives Phase 2 & 3
-Landers and ISRU developments drive Phase 1 then 3 (Phase 2 transition less so)
• Conservative, Margin
-Uses the historical NASA budget growth since 2003
-Cost Inflation 2017 forward per the NASA Inflation Index
-Loses purchasing power over time
• A slight overshoot in Phases 1 & 2
-But having margin in Phase 3
-Consistent with ISS improvement, “future” ISS & post-2024 ISS
-Further optimizing would easily address and eliminate any overshoot
Figure LCC-6. Initial Conservative Scenario. Estimated costs across time for the baseline
Evolvable Lunar Architecture.
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NexGen Space LLC Page 38 Evolvable Lunar Architecture
In close-up, Figure LCC-7 shows the same results as Figure LCC-6 (putting aside
funding within the ISS and other spaceflight budget lines).
Figure LCC-7. Initial Scenario. Close-up of estimated costs across time for the baseline ELA.
However, as mentioned earlier this scenario slightly overshoots the budget constraint.
To understand a baseline life cycle profile, we need to understand its sensitivity to
various factors. To do so, we can vary assumptions for (1) the NASA budget, (2) the
mission rate for the architecture, and (3) the number of providers (partners).
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NexGen Space LLC Page 39 Evolvable Lunar Architecture
For example, typical guidance in NASA cost estimation (either internal guidance, or
external, as from the Office of Management & Budget/OMB) is that any rate of growth of
the NASA budget precisely matches any cost inflation. Making one change, to using a
baseline ELA life cycle cost assumption of a budget growing at the rate of inflation,
results in Figure LCC-8. All the favorable characteristics of the baseline previously
observed still apply, only improved, by virtue of less budget stress and no loss of
purchase power over time.
Figure LCC-8. Scenario with budget growth at rate of inflation. The baseline life cycle cost of
the ELA within a context where budget increases match the rate of cost inflation.
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NexGen Space LLC Page 40 Evolvable Lunar Architecture
Since NASA cannot control inflation, nor can it control its budget, the ability of an
agency to control costs by other means could be critical. An alternative approach to bring
the LCC budget within the budget caps is to alter the mission rates (or flights to the lunar
surface per year.) The baseline ELA life cycle with a variation for the mission rate is in
Figure LCC-9. We do not believe that reducing the flight and mission rate from the target
goals is strictly necessary as we expect that there is likely to be an improvement in the
costs based on NASAs continued presence in LEO post-ISS. This scenario shows the
extreme where no such improvement occurs and the baseline ELA must live strictly
within its yearly budget. As Phase 3 had ample margin, it is able to reach the mission rate
goal as before, but Phase 1 and 2 see a slightly lower mission rate indicated.
Figure LCC-9. Controlling Total Costs by Mission Rate. The baseline life cycle cost of the ELA
within a context where no pre or post-ISS funding is available and the architecture must fit
within its target yearly budget.
NexGen Space LLC Page 41 Evolvable Lunar Architecture
The baseline ELA is all about partnerships. NASA’s recent experience in
development and operations (as services) have involved more than one partner when
applying the partnership model. When comparing traditional development costs to that of
recent partnerships (launch vehicles or spacecraft) any one data point can be compared to
another. To make a fuller contextual comparison, it is necessary to account for how
recent partnerships have the unique characteristic of investing in two providers. If a
NASA investment in two providers is intrinsic to aligning incentives (by creating
competition) in an analog to the COTS/CRS acquisition model, applying individual cost
data from such efforts should reflect retaining two providers. Figure LCC-10 is the
baseline ELA with the condition of two providers for launch services and spacecraft
(including “fillable” in-space stages as apply). Understanding the degree to which dual
partners, requiring two up-front development efforts (NASA investments), is separable or
not from the acquisition model is important in forward work.
Figure LCC-10. Dual Service Providers: Baseline life cycle cost of the ELA with the added
feature of dual launch service providers (including in-space stages and operations).
NexGen Space LLC Page 42 Evolvable Lunar Architecture
Although the slight overage appears to violate the yearly budget guidance, Figure
LCC-11 in the broader context of the entire HEO budget (same as LCC-10) is
manageable with further optimization of the schedule.
Figure LCC-11. Dual Service Providers; Baseline LCC of the ELA with the added feature of
dual launch service providers (including in-space stages and operations), shown in a
broad HEO budget context.
Lastly, a useful variation on the baseline ELA scenario would consider the very
lowest cost path, using the single lowest cost partners. There would be no redundant
providers of any product or service (launch, spacecraft, landers, etc.) In addition, the
variation seen in going from the NASA COTS-CRS acquisition model to the Commercial
Crew acquisition model could conceivably be reduced further, assuming that the
difference is being driven more by non-technical factors rather than technical factors of
kind (cargo to crew). Figure X shows the existing variation in development and
manufacturing costs as the paradigm shifts from commercial cargo, to commercial crew,
This option would be consistent with a “what-if” case of a private investor, if looking
to understand what would be involved in providing an end-to-end service with a singular
purpose, the provision of propellant to a buyer, which could be NASA, at a node in lunar
orbit. The “buyer”, NASA or others, would be acquiring propellant for purposes other
than the Moon, such as for Mars exploration (stages, spacecraft, etc.)
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TBD ISS 2.0
NexGen Space LLC Page 43 Evolvable Lunar Architecture
Figure LCC-12. Variation in LCC by Acquisition Strategy. Variation in development and
manufacturing costs as an acquisition goes from a commercial cargo / service to a
commercial crew / service to a cost-plus crew / owned paradigm.
At a first order, in the private investor case, launch services are less, going with the
lowest cost partner (but lacking redundancy in the supply chain). Similarly, relatively
expensive dual developments, as for cis-lunar spacecraft or lunar landers are roughly
halved, also from having just one partner. Being a private investor, the cost estimates of
crewed spacecraft development and manufacturing are also further reduced from the
Commercial Crew paradigm, assuming further non-technical drivers and efficiencies
from the private investor paradigm. Lastly, government and some related costs have been
removed from this view (program/project management, etc.) Figure LCC-13 shows the
results for this case.
Forward work would be required to mature this case, especially to understand the
technical vs. non-technical drivers in costs diverging as much as shown in Figure LCC-12
in going from the cargo to the crew acquisition. Also, the private investor paradigm has
not been applied to the ISRU related costs (here the same as prior cases). Including the
private investor advantages in the ISRU related developments would further improve this
life cycle profile.
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NexGen Space LLC Page 44 Evolvable Lunar Architecture
Figure LCC-13. LCC Private Investor Scenario. Baseline life cycle cost of the ELA, as a
“lowest cost”, no redundant partners, “private investor” scenario. Since further reductions
in costs are possible under the private investor paradigm, these costs are a likely
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TBD ISS 2.0
NexGen Space LLC Page 45 Evolvable Lunar Architecture
Frequently Asked Questions
1. Cost of First Footsteps on the Moon
In order, drivers of this value are (1) the development of two crewed lunar landers
(dual partners), (2) the development/upgrade of commercial crew spacecraft for
extended cis-lunar operation (dual partners) and (3) the cumulative effects of other
necessary items (launches, stages, etc.) in Phase 1. This cost excludes ISRU and
related developments and is consistent with costs capped at $3B a year, with a first
lunar mission in 2022.
2. Cost of Private Passenger Round Trip to the Moon (Phase 1)
This value is a total round-trip cost. This value would amortize over the total number
of passengers (e.g., if three passengers, ~$250M ea.) In order, this is driven by (1) the
lunar lander (which is expended), (2) a spacecraft (which is only partially reusable,
the crew module) and (3) the number of launchers supporting the prior. It is a
procurement cost, excluding certain government management and related costs.
3. Cost of Repeating Apollo (6 sortie missions to the Moon)
This value excludes ISRU and other related forward developments during this
timeframe. It is consistent with costs capped at $3B a year, with the sixth lunar
mission by 2026. It is a procurement cost, excluding certain government management
and related costs.
4. Cost up to Permanent Operational Lunar Base producing 200 MT/year of Propellant
This is a cumulative cost of all the items (no exclusions) by the start of Phase 3
operations in 2034. It includes all costs, procurement and government management,
DDT&E as well as all the lunar sortie operational mission costs of the previous
decade. It is consistent with costs capped at ~$3B a year.
5. Cost of Private Passenger Round Trip to the Moon (Phase 3)
NexGen Space LLC Page 46 Evolvable Lunar Architecture
As with Question 2, this value is a total round-trip cost. This value would amortize
over the total number of passengers (e.g., if three passengers, ~$160M for each.)
Life Cycle Cost Assessment – Results Summary
The LCC results for the ELA, consistent with improved NASA partnerships and
• Met the ground rule budget target (<$3B a year)
• Met the ground rule mission rate (2 crew launches per year & related cargo etc.)
• Supported the programmatic / NASA budgetary feasibility of tangible evolutionary
progress in exploring / pioneering / milestones in near, relevant timeframes
• Creates numerous commercial acquisition opportunities for private enterprise
– Transportation services to orbit
– Spacecraft services in cis-lunar space
– Propellant markets at < $7,500/kg in LEO (delivered to an interface)
– Propellant markets in lunar orbit
– Spacecraft – smaller prospectors, rovers and landers
– Spacecraft services, lunar surface landers (LCC has two lander providers,
consistent w. COTS/CRS acquisition)
– Cis-lunar commercial communications networks
– Cis-lunar commercial in-space mission control & operations (un-crewed)
– Surface elements; rovers, habitats, equipment, ISRU, etc.
Life Cycle Cost Assessment – Forward Work
Given the promising architecture, approach and results from this LCC assessment,
forward work is well justified. Broadly, the team and analysis capabilities are especially
well suited to address forward work, including:
• Quantify economic, mass and other measures of efficiency in Mars via the Moon
• Subject matter experts & tools are uniquely qualified to integrate an exploration
architecture assessment: Compare performance, reliability and life cycle costs of
comparable staging, evolvable or other Mars architectures vs. Mars via the Moon
• Assess economic efficiency: Requiring less NASA budget, less optimistic NASA
budget assumptions, arriving at Mars/Phobos sooner within a given budget, or overall
less life cycle costs.
• Assess economic advantage: Increasing stakeholders, redundancy in providers, and
indirect economic or commercial advantages.
• Assess mass efficiency: Requiring less IMLEO (Initial Mass in Low Earth Orbit) via
integrating the Moon on the path to Mars (with ISRU and in-space refueling) vs. not.
NexGen Space LLC Page 47 Evolvable Lunar Architecture
• Additional detail, optimization: Refine and address elements to reduce uncertainty
and risks, understanding and providing additional margin specific to elements and life
NexGen Space LLC Page 48 Evolvable Lunar Architecture
Managing Integrated Risks
ELA risk strategies were developed in parallel with initial architecture concept
development considering net integrated “end-to-end” risks that could result in program
failure. We defined and incorporated risk strategies very early during this foundational
phase to drive a successful outcome for the ELA concept. We recognize that decisions
made during the early phases of advanced planning and conceptual design have
significant impacts on supportability
, that the majority of life cycle costs are locked in
by early design, development, and manufacturing trade-off decisions
, and that cost
commitment vs. cost expended data
suggests the Pareto Principle applies such that
approximately 80% of a system's supportability is established by the time 20% of the
design is complete. We believe addressing risk early on when selecting architectural
concepts is every bit as important as building quality in rather than attempting to add it
Imposing risk requirements and processes after key decisions have been made
would likely preclude implementing the most cost-effective options. Likewise, we must
avoid focusing on one specific aspect of risk to the exclusion of other aspects, otherwise
solutions will be sub-optimal for integrated risk.
The ELA considered several different types of risks, broadly, those related to safety,
reliability, and maintainability; technical implementation; as well as business, investment,
cost, schedule, and programmatic risks. For brevity, we will refer to these simply as
“safety and reliability”, “technical”, and “business” risks in this paper, but these terms
include multiple considerations within each category. Safety risk is a key element and is
the combination of (1) the probability that the system will experience an undesired event
(or sequences of events) such as internal system or component failure or an external event
and (2) the magnitude of the consequences given that the undesired event(s) occur(s).
Technical risk includes inability to meet performance or technology objectives. Business
risks includes events which could cause the company or program to fail. Examples
include inability to obtain financing, running out of funds before sufficient revenues are
available, inability to satisfy regulatory requirements, failure of a critical customer or
supplier, and lack of sufficient market demand or political support.
The term “integrated risk” is used to include the net effect of all three risk types taken
together. Although often steps taken to manage one type of risk negatively impact one or
both other risks, this is not necessarily the case and two or more of these risks can be
addressed synergistically. For example, launching a set of five robotic scouts per each of
two early version FH vehicles not only addresses the technical and business risks of
locating suitable resources, it also reduces safety and reliability risk by increasing FH
flight experience. Note that while we have a separate discussion of business risks related
to governance models because of the special importance of this consideration, other
business risks were considered together with safety and technical risks throughout the
Risks must also be considered for multiple mission phases and through the life of a
program. For example, a crew launch program that is focused on reducing ascent phase
risk by limiting the number of engines as possible failure sources may reduce its mass
allocation so much that robustness, which is designing with margins able to
accommodate large uncertainties, is no longer possible, while cost and technical risks are
increased. This may result in low launch phase risk, but risks due to in-space effects such
as micro-meteoroid or orbital debris may be extraordinarily (and unnecessarily) high,
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resulting in a sub-optimized net mission end-to-end risk than if a balanced, integrated
approach had been taken.
Safety and Reliability Risks
ELA success depends on effective management of a number of risks relating to safety
of crew, delivery of cargo, and operational availability of many different types of
equipment. A variety of failures and anomalies are inevitable and must be expected to
occur while conducting any program of this magnitude, especially given the harsh
environments and long durations these systems must operate. Identification of possible
problems, consideration for their likelihood and consequence, and planning how they can
be dealt with at the very inception of the program are all elements of what we call risk
strategy. We have identified means to mitigate risks such as Loss of Mission, Loss of
Crew, and even Loss of Program that can be incorporated early in the architecture
concept development, where a very high level of leverage can be expected.
Defining effective risk strategies at this stage of formulation will greatly increase the
chance that future work involving detailed reliability and risk analyses will yield
favorable results. Although the level of detail and definition to perform such analyses is
not available at this time, the strategies developed in this study are based on decades of
experience with similarly challenging programs. However, implementation of the risk
strategies identified in this study are not sufficient in themselves to ensure future success.
As the program goes forward, more detailed reliability, safety, maintainability,
probabilistic risk, and similar analyses and processes should be implemented, although
the level of effort should be tailored to the levels of risk remaining given the risk
strategies and the extent to which they are adopted.
The ELA approach to vehicle system safety and reliability risks was conceived with
several concepts in mind that are concurrently and coincidentally being developed in
studies of Resilient Architectures
as applied to urban design. In this context,
“resilience” is the ability of complex systems to operate with stability, not only within
their normal design parameters, but also to be safely sustained through unexpected events
or changing needs. While we know that we cannot design for every possible and
unpredictable failure or other disruptive event (including external events such as those
related to space or lunar environments), we can develop and apply various strategies to
ensure that our systems can operate through disruptions and bounce back afterwards.
The above referenced article on resilient architectures notes that we can learn much
from biological systems, which are incredibly complex in terms of number of
components and interactions, yet have proven to be stable over many thousands of years
in spite of countless disruptions and “shocks to the system.” Some of these lessons and
how we can apply them to the ELA to reduce risk include:
(1) These systems are distributed (non-centralized) and have an inter-connected
network structure. This lesson can be applied to our architecture through
application of common interfaces and standards which can interconnect our
components, elements, systems, and sub-systems in multiple ways rather than by
segregating them into neat categories of use, type, or pathway, which would make
them more vulnerable to failure.
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(2) They feature diversity and redundancy. This lesson can be applied to the ELA by
having a variety of different kinds of components, elements, and subsystems,
provided by different organizations, nationalities, cultures, and individuals, doing
things in different ways, any one of which might provide the key to surviving a
shock to the system (precisely which can never be known in advance).
(3) They display a wide distribution of structures across scales. This lesson can be
applied to the ELA in developing the means by which we start with small scale
tests and demonstrations, from which we can develop modular capabilities for
functions such as resource location, characterization, extraction, ISRU processing,
power, life support, and propellant delivery. These modular functions can then be
replicated to increase capacity. Combining with (1) and (2) above, these structures
are diverse, inter-connected, and can be changed relatively easily and locally (in
response to changing needs).
(4) They have the capacity to self-adapt and “self-organize.” Following from (3),
ELA capabilities (and their parts) could be adapted and reorganized in response to
failures, as well as evolutionary learning and discovery of new knowledge about
what works (or not), or other changing needs.
Risk Strategies to Mitigate Loss of Launch Vehicle
The fundamental strategy to address the risk of launch vehicle failures is that no
single launch failure should ever be catastrophic to Program success. This strategy is
enabled by commercial acquisition and operation costs being nearly an order of
magnitude lower than traditional approaches and is flowed through the entire
architecture. The ELA features a large number of relatively low cost launches for each
mission, potentially on some relatively immature new launch vehicles. This has raised
concerns about what happens if one or more of these launches (or subsequent on-orbit
operations) fail. This has been the subject of much investigation, both as part of this study
and in prior studies by the author.
xxviii , xxix
A very effective strategy to manage this risk is
to provide for contingency launches.
Using what is called “M of N” reliability techniques, any desired level of reliability
(sometimes referred to as the number of 9's) for any given number of required launches
(M) can be provided by planning for some greater number of launch vehicles (N),
assuming any reasonable level of inherent reliability of the base vehicle being used. The
difference between N and M is the number of contingencies provided. Selection of the
number of contingency launches should be based on the expected Probability of Success
per launch, the required overall success probability for the mission set, and consideration
for tolerance to payload loss and schedule risk. These parameters should be traded to
identify the most cost-effective solution. This strategy, shown in Figure RS-1, is effective
when the consequence of losses, up to at least the planned number of contingency flights,
is acceptable. An analysis of Falcon 9 reliability was performed (Appendix 1) and
showed that the experience to the date of the analysis (March 2015) is bounded by the
bars for low and high launch vehicle reliability, as shown in Figure RS-1.
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Figure RS-1: Use Contingency Flights for Multiple-Launches.
The Overall Mission
Probability of Success (Ps), when many launches (M) are required, depends upon the Per
Launch Reliability (R) and total number of launches planned (N), including contingency launches.
Multiple providers protect against delays during failure investigation and has proven to be of great
importance for ISS commercial cargo.
Extremely high Mission Ps can be achieved with just a
few contingency launches. This strategy allows vehicles with relatively low reliability or as yet
undemonstrated reliability to provide a high probability of overall mission success if even a small
number of contingency launches are planned. Even highly reliable launch vehicles can have a
relatively low Mission Ps there are no contingencies planned. This is an especially effective
strategy for rapidly maturing new vehicles through propellant delivery roles. It is also effective for
in-space or lunar elements where multiple like-units are utilized and launched as a series.
While the “M of N” strategy could be applied with just a single launch vehicle
provider, the ELA risk strategy includes having at least two independent dissimilar
launch vehicle providers operating from separate launch facilities, with payloads
designed to a common standard to enable integration with either vehicle. Multiple
independent providers are particularly important to address any down time resulting from
needs to investigate failure cause and implement a corrective action to prevent a
recurrence. Multiple launch facilities are important to mitigate delays caused by potential
damage to the launch pads.
The strategy of having redundant providers is possible because of sufficient launch
demand to support more than one provider and the public-private-partnership approach,
which properly aligns incentives, thereby creating affordable systems. Since the systems
are each affordable, two can now be afforded (especially critical in development) where
before only one might have been possible. Furthermore, redundant providers reduces
business risk by creating competition at the vehicle design level, while fostering
cooperation at operational and supply chain levels by implementing design standards,