**Testimony of Dr. Paul D. Spudis at the Subcommittee on Science,
Technology, and Space, Senate Commerce, Science, and Transportation
Committee hearing on "Lunar Exploration"**

Dr. Paul D. Spudis

Planetary Scientist

Lunar and Planetary Institute

## *November 6, 2003*

Mr. Chairman and members of the committee, thank you for inviting me
here today to testify on the subject of lunar exploration and the US
space program.

I want to discuss a new destination for America in space -- the Moon.
Although we conducted our initial visits to that body over 30 years ago,
we have recently made several important discoveries that indicate a
return to the Moon offers many advantages and benefits to the nation. In
addition to being a scientifically rich object for study, the Moon
offers abundant material and energy resources, the feedstock of an
industrial space infrastructure. Once established, such an
infrastructure will revolutionize space travel, assuring us of
continuous, routine access to cislunar space (i.e., the space between
and around Earth and Moon) and beyond. The value of the Moon as a space
destination has not escaped the notice of other countries -- at least
four new robotic missions are currently being flown or prepared by
Europe, India, Japan, and China and advanced planning for human missions
in many of these countries is already underway.

With me here today is Dr. Bill Stone, a prominent explorer and
expedition leader. The points which I will present represent our joint
thinking as to WHY the nation needs to return to the Moon and why that
return should take place NOW rather than later.

(1) NASA needs a politically viable mission and both Shuttle and ISS are
    losing appeal as "space exploration." America needs a compelling
    space program!

Forty years ago, America made a decision to go to the Moon, starting
from a state of primitive technology and vast ignorance. We accomplished
this great feat within 8 years, giving us for the first time the ability
to travel to another world. We now have a commercial launch industry
that each year lifts a mass equivalent to an Apollo mission to
geosynchronous orbit. Its mission accomplished, NASA looked to other
programs to keep the dream of space flight alive. Shuttle was presented
as an affordable means to low Earth orbit. Space Station was planned as
both a laboratory in orbit and a way station to the rest of the Solar
System. Meanwhile, the Moon largely was ignored as an object worthy of
study in its own right, as a natural space station to provision and
enable space flight farther a field, and as a center of commerce and
national security.

NASA's current problems are partly technical, but mostly related to the
fact that it no longer has a mission, as in its early "Days of Glory."
Forty years ago, its mission was to beat the Soviets to the Moon, a
clear goal articulated by the national leadership and presented with a
deadline (by the end of the decade). Now, the agency looks for a
mission, but has yet to find one, at least, one perceived by government
and the American people as worthy of long-term commitment. In the
absence of such a goal, we drift between projects and have some success,
but nothing is cumulative, where each step builds upon and extends the
capability of the step preceding it.

A new national focus in space must have a direct and clear benefit to
the American public. Pure science and the search for life are not
defensible justifications. As Dr. Stone has put it recently, what the
nation needs is a Lewis and Clark-class mission -- one that opens the
frontier to the expansion of the external commerce of the United States
(through the general participation of its people and industry) and to
the enhancement of the security of the nation. The recent loss of
Shuttle Columbia has only heightened the perception that we are adrift
in space, with no long-term goals or direction. Death and risk are part
of life and not to be feared, especially in the field of exploration,
but for death to have meaning, the objectives of such exploration must
be significant. Great nations do great (and ambitious) things. The
Apollo project was one such example; a return to the Moon to learn how
to live off-planet can be another.

(2) Human missions to Mars currently are too technically challenging and
    too expensive to be feasible national space goals within the next
    decade.

Although much attention is given to the idea of human missions to Mars
as the next big goal in space, such a journey is at present beyond our
technical and economic capabilities. The large amount of discretionary
money needed for such a journey is simply not available in the federal
budget nor would it be wisely spent on going to Mars in an Apollo-style
"flags-and-footprints" program. The principal justification of a manned
Mars mission is scientific and such a rationale cannot sustain a large
investment in the eyes of the taxpaying public. Mars awaits exploration
by people some time in the future, after we have learned how to live and
work routinely in space and how to make use of the resources available
on other worlds to break the costly ties to Earth-based rocket transport
of materiel.

American government has a history of supporting long-term, big
engineering projects, provided that such efforts contribute to goals
related to national and economic security (e.g., the Panama Canal, the
Apollo program). The nation needs a mission whose purpose relates to
these important, enduring objectives. A return to the Moon is such a
goal. Indeed, it is a necessary goal and the only
economically-justifiable goal at this time.

(3) Other possible destinations for people in space are perceived to be
    either too uninteresting (asteroids) or too arcane (telescopes in
    deep space) to enjoy "widespread" national support.

Among other possible space destinations for people are the Lagranian
(L-) points (imaginary spots in space that move in sync with Earth,
Moon, Sun or other objects) and the minor planets, better known as
asteroids. The Lagranian points have many advantages for the staging of
missions that go elsewhere, but the only thing they contain is what we
put there. In that sense, they are similar to low Earth orbit and
significant activity at the L-points, without travel beyond them to more
interesting destinations, would resemble another International Space
Station put in a different location. Asteroids have great potential for
exploration and exploitation of resources and may eventually become an
important destination as a class of objects. However, the times required
to reach asteroids can equal the months-long transit times for Mars
missions, without the variety of activities that could be undertaken at
the end of such a trip. Thus, although specialized missions to these
destinations can be imagined, they do not present a compelling return on
investment nor the scientific or operational variety that other missions
possess.

(4) The Moon is close, accessible with existing systems, and has
    resources that we can use to create a true, economical space-faring
    infrastructure

The Moon is a scientific and economic treasure trove, easily reachable
with existing systems and infrastructure that can revolutionize our
national strategic and economic posture in space. The dark areas near
the poles of the Moon contain significant amounts (at least 10 billion
tons) of hydrogen, most probably in the form of water ice. This ice can
be mined to support human life on the Moon and in space and to make
rocket propellant (liquid hydrogen and oxygen). Moreover, we can return
to the Moon using the existing infrastructure of Shuttle and
Shuttle-derived launch systems and the ISS for only a modest increase in
the space budget within the next five years.

The "mission" of this program is to go to the Moon to learn how to use
off-planet resources to make space flight easier and cheaper in the
future. Rocket propellant made on the Moon will permit routine access to
cislunar space by both people and machines, which is vital to the
servicing and protection of national strategic assets and for the repair
and refurbishing of commercial satellites. The availability of cheap
propellant in low Earth orbit would completely change the way engineers
design spacecraft and the way companies and the government think of
investing in space assets. It would serve to dramatically reduce the
cost of space infrastructure to both the government and to the private
sector, thus spurring economic investment (and profit).

(5) The Moon is a scientific treasure house and a unique resource, on
    which important research, ranging from planetary science to
    astronomy and high-energy physics, can be conducted.

Generally considered a simple, primitive body, the Moon is actually a
small planet of surprising complexity. Moreover, the period of its most
active geological evolution, between 4 and 3 billion years ago,
corresponds to a "missing chapter" of Earth history. The processes that
work on the Moon -- impact, volcanism, and tectonism (deformation of the
crust) -- are the same ones that affect all of the rocky bodies of the
inner solar system, including the Earth. Because the Moon has no
atmosphere or running water, its ancient surface is preserved in nearly
pristine form and its geological story can be read with clarity and
understanding. Because the Moon is Earth's companion in space, it
retains a record of the history of this corner of the Solar System,
vital knowledge unavailable on any other planetary object.

Of all the scientific benefits of Apollo, appreciation of the importance
of impact, or the collision of solid bodies, in planetary evolution must
rank highest. Before we went to the Moon, we had to understand the
physical and chemical effects of these collisions, events completely
beyond the scale of human experience. Of limited application at first,
this new knowledge turned out to have profound consequences. We now
believe that large-body collisions periodically wipe out species and
families on Earth, most notably, the extinction of dinosaurs 65 million
years ago. The telltale residue of such large body impacts in Earth's
past is recognized because of knowledge we acquired about impact from
the Moon. Additional knowledge still resides there; while the Earth's
surface record has been largely erased by the dynamic processes of
erosion and crustal recycling, the ancient lunar surface retains this
impact history. When we return to the Moon, we will examine this record
in detail and learn about its evolution as well as our own.

Because the Moon has no atmosphere and is a quiet, stable body, it is
the premier place in space to observe the universe. Telescopes erected
on the lunar surface will possess many advantages. The Moon's level of
seismic activity is orders of magnitude lower than that of Earth. The
lack of an atmosphere permits clear viewing, with no spectrally opaque
windows to contend with; the entire electromagnetic spectrum is visible
from the Moon's surface. Its slow rotation (one lunar day is 708 hours
long, about 28 terrestrial days) means that there are long times of
darkness for observation. Even during the lunar day, brighter sky
objects are visible through the reflected surface glare. The far side of
the Moon is permanently shielded from the din of electromagnetic noise
produced by our industrial civilization. There are areas of perpetual
darkness and sunlight near the poles of the Moon. The dark regions are
very cold, only a few tens of degrees above absolute zero and these
natural "cold traps" can be used to passively cool infrared detectors.
Thus, telescopes installed near the lunar poles can both see entire
celestial hemispheres all at once and with infrared detectors, cooled
for "free," courtesy of the cold traps.

(6) Hydrogen, probably in the form of water ice, exists at the poles of
    the Moon that can be extracted and processed into rocket propellant
    and life-support consumables

The joint DoD-NASA Clementine mission was flown in 1994. Designed to
test sensors developed for the Strategic Defense Initiative (SDI),
Clementine was an amazing success story. This small spacecraft was
designed, built, and flown within the short time span of 24 months for a
total cost of about \$150 M (FY 2003 dollars), including the launch
vehicle. Clementine made global maps of the mineral and elemental
content of the Moon, mapped the shape and topography of its surface with
laser altimetry, and gave us our first good look at the intriguing and
unique polar regions of the Moon. Clementine did not carry instruments
specifically designed to look for water at the poles, but an ingenious
improvisation used the spacecraft communications antenna to beam radio
waves into the polar regions; radio echoes were observed using the Deep
Space Network dishes. Results indicated that material with reflection
characteristics similar to ice are found in the permanently dark areas
near the south pole. This major discovery was subsequently confirmed by
a different experiment flown on NASA's Lunar Prospector spacecraft four
years later in 1998.

The Moon contains no internal water; all water is added to it over
geological time by the impact of comets and water-bearing asteroids. The
dark areas near the poles are very cold, only a few degrees above
absolute zero. Thus, any water that gets into these polar "cold traps"
cannot get out so over time, significant quantities accumulate. Our
current best estimate is that over 10 billion cubic meters of water
exist at the lunar poles, an amount equal to the volume of Utah's Great
Salt Lake -- without the salt! Although hydrogen and oxygen can be
extracted directly from the lunar soil (solar wind hydrogen is implanted
on the dust grains of the surface, allowing the production of propellant
and water directly from the bone-dry dust), such processing is difficult
and energy-expensive. Polar water has the advantage of already being in
a concentrated useful form, greatly simplifying scenarios for lunar
return and habitation. Broken down into hydrogen and oxygen, water is a
vital substance both for human life support and rocket propellant. Water
from the lunar cold traps advances our space-faring infrastructure by
creating our first space "filling station."

The poles of the Moon are useful from yet another resource perspective
-- the areas of permanent darkness are in proximity to areas of
near-permanent sunlight. Because the Moon's axis of rotation is nearly
perpendicular to the plane of the ecliptic, the sun always appears on or
near the horizon at the poles. If you're in a hole, you never see the
Sun; if you're on a peak, you always see it. We have identified several
areas near both the north and south poles of the Moon that offer
near-constant sun illumination. Moreover, such areas are in darkness for
short periods, interrupting longer periods of illumination. Thus, an
outpost or establishment in these areas will have the advantage of being
in sunlight for the generation of electrical power (via solar cells) and
in a benign thermal environment (because the sun is always at grazing
incidence); such a location never experiences the temperature extremes
found on the lunar equator (from 100° to --150° C). The poles of the
Moon are inviting "oases" in near-Earth space.

(7) Current launch systems, infrastructure, and space hardware can be
    adapted to this mission and we can be back on the Moon within five
    to seven years for only a modest increase in existing space budgets.

America built the mighty Saturn V forty years ago to launch men and
machines to the Moon in one fell swoop. Indeed, this technical approach
was so successful, it has dominated the thinking on lunar return for
decades. One feature of nearly all lunar return architectures of the
past twenty years is the initial requirement to build or re-build the
heavy lift launch capability of the Saturn V or its equivalent. Parts of
the Saturn V were literally hand-made, making it a very expensive
spacecraft. Development of any new launch vehicle is an enormously
expensive proposition. What is needed is an architecture that
accomplishes the goal of lunar return with the least amount of new
vehicle development possible. Such a plan will allow us to concentrate
our efforts and energies on the most important aspects of the mission --
learning how to use the Moon's resources to support space flight.

One possible architecture for lunar return devised by the Office of
Exploration at the Johnson Space Center has several advantages. First,
and most importantly, it uses the Space Shuttle (or an unmanned
derivative of it), augmented by existing expendable boosters, to deliver
the pieces of the lunar spacecraft to orbit. Thus, from the start, we
eliminate one of the biggest sources of cost from the equation, the
requirement to develop a new heavy-lift launch vehicle. This plan uses
existing expendable launch vehicle (ELV) technology to deliver the cargo
elements of the lunar return to low Earth orbit -- lander, habitat, and
transfer stage. Assembled into a package in Earth orbit, these items are
then transferred to a point about 4/5 of the way to the Moon, the
Moon-Earth Lagranian point 1 (L1). The L1 point orbits the Earth with
the Moon such that it appears "motionless" to both bodies. Its
non-motion relative to Earth and Moon has the advantage of allowing us
to wait for favorable alignments of these bodies and the Space Station
in various phases of the mission. Because there is no requirement for
quick transit, cargo elements can take advantage of innovative
technologies such as solar electric propulsion and weak stability
boundaries between Earth, Sun, and Moon to make long, spiraling trips
out to L1, thus requiring less propellant mass. These unmanned cargo
spacecraft can take several months to get to their destinations. The
habitat module can be landed on the Moon by remote control, activated,
and await the arrival of its occupants from Earth.

The crew is launched separately on a Shuttle launch and uses a chemical
stage and a quick transfer trajectory to reach the L1 depot in a few
days. The crew then transfers to the lunar lander/habitat, descends to
the surface and conducts the surface mission. As mentioned above, the
preferred landing site is an area near one of the Moon's poles; the
south pole is most attractive from the perspective of science and
operations (see the attached "Shackleton Crater Expedition" proposal
submitted to the committee by Dr. Stone). The goal of our mission is to
learn how to mine the resources of the Moon as we build up surface
infrastructure to permit an ever-larger scale of operations. Thus, each
mission brings new components to the surface and the size and capability
of the lunar outpost grows over time. Most importantly, the use of
lunar-derived propellants means that more than 80% of the spacecraft
weight on return to Earth orbit need not be brought from Earth. A
properly designed mission will return to Earth not only with sufficient
fuel to take the craft back to the Moon for another run, but also to
provide a surplus for sale in low Earth orbit. It is this act that
creates the Earth-Moon economy and demonstrates a positive return on
investment.

On return, the L1 depot provides a safe haven for the crew while they
wait several days for the orbital plane of ISS to align itself with the
return path of the crew vehicle. Rather than directly entering the
atmosphere as Apollo did, the crew return vehicle uses aerocapture to
brake into Earth orbit, rendezvous with the ISS, and thus, it becomes
available for use in the next lunar mission.

In addition to its technical advantages, this architecture offers
important programmatic benefits. It does not require the development of
a new heavy lift launcher. We conduct our lunar mission from the ISS and
return to it afterwards, making the Station an essential component of
humanity's movement into the Solar System. The use of the L1 point as a
staging depot allows us to wait for proper alignments of the Earth and
Moon; the energy requirements to go nearly anywhere beyond this point
are very low. The use of newly developed, low-thrust propulsion (i.e.,
solar-electric) for cargo elements drives new technology development. We
will acquire new technical innovation as a by-product of the program,
not as a critical requirement of the architecture.

The importance of using the Shuttle or Shuttle-derived launch vehicles
and commercial launch assets in this architecture should not be
underestimated. Costs in space launch are almost completely dominated by
the costs of people and infrastructure. To create a new launch system
requires new infrastructure, new people, new training. Such costs can
make up significant fractions of the total program. By using existing
systems, we can concentrate our resources on new equipment and
technology, focused on the goal of finding, characterizing, processing,
and using lunar resources as soon as possible.

(8) A return to the Moon gives the nation a challenging mission and
    creates capability for the future, by allowing us to routinely
    travel at will, with people, throughout the Earth-Moon system.

Implementation of this objective for our national space program would
have the result of establishing a robust transportation infrastructure,
capable of delivering people and machines throughout cislunar space.
Make no mistake -- learning to use the resources of the Moon or any
other planetary object will be a challenging technical task. We must
learn to use machines in remote, hostile environments, working under
difficult conditions with ore bodies of small concentration. The unique
polar environment of the Moon, with its zones of near-permanent
illumination and permanent darkness, provides its own challenges. But
for humanity to have a future, we must learn to use the materials
available off-planet. We are fortunate that the Moon offers us a nearby,
"safe" laboratory to take our first steps in using space resources.
Initial blunders in mining tactics or feedstock processing are better
practiced at a location three days from Earth than from one many months
away.

A mission learning to use these lunar resources is scalable in both
level of effort and the types of commodities to be produced. We begin by
using the resources that are the easiest to extract. Thus, a logical
first product is water derived from the lunar polar deposits. Water is
producible here regardless of the nature of the polar volatiles -- ice
of cometary origin is easily collected and purified, but even if the
polar materials are composed of molecular hydrogen, this substance can
be combined with oxygen extracted from rocks and soil (through a variety
of processes) to make water. Water is easily stored and used as a
life-sustaining substance for people or broken down into its constituent
hydrogen and oxygen for use of rocket propellant.

Although we currently possess enough information to plan a lunar return
now, investment in a few robotic precursors would be greatly beneficial.
We should map the polar deposits of the Moon from orbit using imaging
radar to "see" the ice in the dark regions. Such mapping could establish
the details of the ice location and its thickness, purity, and physical
state. The next step should be to land small robotic probes to conduct
in place chemical analyses of the material. Although we expect water ice
to dominate the deposit, cometary cores are made up of many different
substances, including methane, ammonia, and organic molecules, all of
which are potentially useful resources. We need to inventory these
species, determine their chemical and isotopic properties, and their
physical nature and environment. Just as the way for Apollo was paved by
such missions as Ranger and Surveyor, a set of robotic precursor
missions, conducted in parallel with the planning of the manned
expeditions, can make subsequent human missions safer and more
productive.

After the first robotic missions have documented the nature of the
deposits, focused research efforts would be undertaken to develop the
machinery needed to be transported to the lunar base as part of the
manned expedition. There, human-tended processes and principles will be
established and validated, thus paving the way to commercialization of
the mining, extraction and production of lunar hydrogen and oxygen.

(9) This new mission will create routine access to cislunar space for
    people and machines, which directly relates to important national
    economic and strategic goals.

By learning space survival skills close to home, we create new
opportunities for exploration, utilization, and wealth creation. Space
will no longer be a hostile place that we tentatively visit for short
periods; it becomes instead a permanent part of our world. Achieving
routine freedom of cislunar space makes America more secure (by enabling
larger, cheaper, and routinely maintainable assets on orbit) and more
prosperous (by opening an essentially limitless new frontier.)

As a nation, we rely on a variety of government assets in cislunar
space, ranging from weather satellites to GPS systems to a wide variety
of reconnaissance satellites. In addition, commercial spacecraft
continue to make up a multi-billion dollar market, providing telephone,
Internet, radio and video services. America has invested billions in
this infrastructure. Yet at the moment, we have no way to service,
repair, refurbish or protect any of these spacecraft. They are
vulnerable to severe damage or permanent loss. If we lose a satellite,
it must be replaced. From redesign though fabrication and launch, such
replacement takes years and involves extraordinary investment in the
design and fabrication so as to make them as reliable as possible.

We cannot now access these spacecraft because it is not feasible to
maintain a man-tended servicing capability in Earth orbit -- the costs
of launching orbital transfer vehicles and propellant would be excessive
(it costs around \$10,000 to launch one pound to low Earth orbit).
Creating the ability to refuel in orbit, using propellant derived from
the Moon, would revolutionize the way we view and use our national space
infrastructure. Satellites could be repaired, rather than abandoned.
Assets can be protected rather than written off. Very large satellite
complexes could be built and serviced over long periods, creating new
capabilities and expanding bandwidth (the new commodity of the
information society) for a wide variety of purposes. And along the way,
we will create opportunities and make discoveries.

A return to the Moon, with the purpose of learning to mine and use its
resources, thus creates a new paradigm for space operations. Space
becomes a part of America's industrial world, not an exotic environment
for arcane studies. Such a mission ties our space program to its
original roots in making us more secure and more prosperous. But it also
enables a broader series of scientific and exploratory opportunities. If
we can create a spacefaring infrastructure that can routinely access
cislunar space, we have a system that can take us to the planets.

(10) The infrastructure created by a return to the Moon will allow us to
     travel to the planets in the future more safely and cost
     effectively.

This benefit comes in two forms. First, developing and using lunar
resources can enable flight throughout the Solar System by permitting
the fueling the interplanetary craft with materiel already in orbit,
saving the enormous costs of launch from Earth's surface. Second, the
processes and procedures that we learn on the Moon are lessons that will
be applied to all future space operations. To successfully mine the
Moon, we must learn how to use machines and people in tandem, each
taking advantage of the other's strengths. The issue isn't "people or
robots?" in space; it's "how can we best use people and robots in
space?" People bring the unique abilities of cognition and experience to
exploration and discovery; robots possess extraordinary stamina,
strength, and sensory abilities. We can learn on the Moon how to best
combine these two complementary skill mixes to maximize our exploratory
and exploitation abilities.

Return to the Moon will allow us to regain operational experience on
another world. The activities on the Moon make future planetary missions
less risky because we gain this valuable experience in an environment
close to Earth, yet on a distinct and unique alien world. Systems and
procedures can be tested, vetted, revised and re-checked. Exploring a
planet is a difficult task to tackle green; learning to live and work on
the Moon gives us a chance to crawl before we have to walk in planetary
exploration and surface operations.

The establishment of the Earth-Moon economy may be best accomplished
through an independently organized federal expedition along the lines of
the Lewis and Clark expedition. Dr. Stone, who is eminently qualified to
lead such an expedition, has prepared the Shackleton Crater Expedition
proposal (attached to this testimony) to elaborate upon this alternative
organizational strategy. One of the fundamental tenets of this approach
is to take a business stance on cost control with the objective of
demonstrating a positive return on investment. Such an approach would
take advantage of the best that NASA and other federal agencies have to
offer, while streamlining the costs through a series of hard-nosed
business approaches.

A lunar program has many benefits to society in general. America needs a
challenging, vigorous space program. Such a program has served as an
inspiration to the young for the last 50 years and it can still serve
that function. It must present a mission that inspires and enriches. It
must relate to important national needs yet push the boundaries of the
possible. It must serve larger national concerns beyond scientific
endeavors. A return to the Moon fulfills these goals. It is a technical
challenge to the nation. It creates security for America by assuring
access and control of our assets in cislunar space. It creates wealth
and new markets by producing commodities of great commercial value. It
stimulates and inspires the next generation by giving them the chance to
travel and experience space flight for themselves. A return to the Moon
is the right destination for America.

Thank you for your attention.