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An Apollo astronaut argues that with its vast stores of nonpolluting nuclear fuel, our lunar neighbor holds the key to Earth's future. However, before we mine it, we'll need to determine who owns the moon?
A
sample of soil from the rim of Camelot crater slid from my scoop into a
Teflon bag to begin its trip to Earth with the crew of Apollo 17. Little did I know at the time, on Dec. 13, 1972, that sample 75501, along with samples from Apollo 11
and other missions, would provide the best reason to return to the moon
in the 21st century. That realization would come 13 years later. In
1985, young engineers at the University of Wisconsin discovered that
lunar soil contained significant quantities of a remarkable form of
helium. Known as helium-3, it is a lightweight isotope of the familiar
gas that fills birthday balloons.
Small
quantities of helium-3 previously discovered on Earth intrigued the
scientific community. The unique atomic structure of helium-3 promised
to make it possible to use it as fuel for nuclear fusion, the process
that powers the sun, to generate vast amounts of electrical power
without creating the troublesome radioactive byproducts produced in
conventional nuclear reactors. Extracting helium-3 from the moon and
returning it to Earth would, of course, be difficult, but the potential
rewards would be staggering for those who embarked upon this venture.
Helium-3 could help free the United States--and the world--from
dependence on fossil fuels.
That
vision seemed impossibly distant during the decades in which manned
space exploration languished. Yes, Americans and others made repeated
trips into Earth orbit, but humanity seemed content to send only robots
into the vastness beyond. That changed on Jan. 14, 2004, when President
George W. Bush challenged NASA to "explore space and extend a human
presence across our solar system."
It
was an electrifying call to action for those of us who share the vision
of Americans leading humankind into deep space, continuing the ultimate
migration that began 42 years ago when President John F. Kennedy first
challenged NASA to land on the moon. We can do so again. If Bush's
initiative is sustained by Congress and future presidents, American
leadership can take us back to the moon, then to Mars and, ultimately,
beyond.
Although the
president's announcement did not mention it explicitly, his message
implied an important role for the private sector in leading human
expansion into deep space. In the past, this type of public-private
cooperation produced enormous dividends. Recognizing the distinctly
American entrepreneurial spirit that drives pioneers, the President's
Commission on Implementation of U.S. Space Exploration Policy
subsequently recommended that NASA encourage private space-related
initiatives. I believe in going a step further. I believe that if
government efforts lag, private enterprise should take the lead in
settling space. We need look only to our past to see how well this could
work. In 1862, the federal government supported the building of the
transcontinental railroad with land grants. By the end of the 19th
century, the private sector came to dominate the infrastructure,
introducing improvements in rail transport that laid the foundation for
industrial development in the 20th century. In a similar fashion, a
cooperative effort in learning how to mine the moon for helium-3 will
create the technological infrastructure for our inevitable journeys to
Mars and beyond.
The
Basics of Limitless Power: Albert Einstein's famous E=MC2 equation
reflects the enormous energy that can be released by fusing atoms.
Hydrogen atoms fusing together to create helium powers the sun.
1. FIRST GENERATION:
Scientists have duplicated solar fusion on Earth by using two "heavy"
hydrogen atoms--deuterium and tritium--which fuse at lower temperatures
than ordinary hydrogen. A first-generation deuterium-tritium fusion
reactor operated experimentally for 15 years at the Princeton Plasma
Physics Laboratory in New Jersey.
2. SECOND GENERATION:
While useful for studying fusion, reactors operating with
deuterium-tritium fuel are impractical for commercial use. Among other
things, the reaction produces large amounts of radiation in the form of
neutrons. Substituting helium-3 for tritium significantly reduces
neutron production, making it safe to locate fusion plants nearer to
where power is needed the most, large cities. This summer, researchers
at the University of Wisconsin Fusion Technology Institute in Madison
reported having successfully initiated and maintained a fusion reaction
using deuterium and helium-3 fuel.
3. THIRD GENERATION:
First-generation fusion reactors were never intended to produce power.
And, even if they are perfected, they would still produce electricity in
much the same way as it is created today. That is, the reactors would
function as heat sources. Steam would then be used to spin a massive
generator, just as in a coal- or oil-fired plant. Perhaps the most
promising idea is to fuel a third-generation reactor solely with
helium-3, which can directly yield an electric current--no generator
required. As much as 70 percent of the energy in the fuels could be
captured and put directly to work.--Stefano Coledan
A Reason To Return
Throughout
history, the search for precious resources--from food to minerals to
energy--inspired humanity to explore and settle ever-more-remote regions
of our planet. I believe that helium-3 could be the resource that makes
the settlement of our moon both feasible and desirable.
Although
quantities sufficient for research exist, no commercial supplies of
helium-3 are present on Earth. If they were, we probably would be using
them to produce electricity today. The more we learn about building
fusion reactors, the more desirable a helium-3-fueled reactor becomes.
Researchers
have tried several approaches to harnessing the awesome power of
hydrogen fusion to generate electricity. The stumbling block is finding a
way to achieve the temperatures required to maintain a fusion reaction.
All materials known to exist melt at these surface-of-the-sun
temperatures. For this reason, the reaction can take place only within a
magnetic containment field, a sort of electromagnetic Thermos bottle.
Initially,
scientists believed they could achieve fusion using deuterium, an
isotope of hydrogen found in seawater. They soon discovered that
sustaining the temperatures and pressures needed to maintain the
so-called deuterium-deuterium fusion reaction for days on end exceeded
the limits of the magnetic containment technology. Substituting helium-3
for tritium allows the use of electrostatic confinement, rather than
needing magnets, and greatly reduces the complexity of fusion reactors
as well as eliminates the production of high-level radioactive waste.
These differences will make fusion a practical energy option for the
first time.
It is not a
lack of engineering skill that prevents us from using helium-3 to meet
our energy needs, but a lack of the isotope itself. Vast quantities of
helium originate in the sun, a small part of which is helium-3, rather
than the more common helium-4. Both types of helium are transformed as
they travel toward Earth as part of the solar wind. The precious isotope
never arrives because Earth's magnetic field pushes it away.
Fortunately, the conditions that make helium-3 rare on Earth are absent
on the moon, where it has accumulated on the surface and been mixed with
the debris layer of dust and rock, or regolith, by constant meteor
strikes. And there it waits for the taking.
An
aggressive program to mine helium-3 from the surface of the moon would
not only represent an economically practical justification for permanent
human settlements; it could yield enormous benefits back on Earth.
Budget cuts, a public bored with space and fear of losing a crew--Apollo 13
was still a vivid memory--turned Apollo 17 into the last moon mission
of the 20th century. NASA decided to get the most scientific data
possible from its last lunar excursion and made a crew change: Harrison
H. Schmitt became the first and only fully trained geologist to explore
the moon. Schmitt was a natural choice. With a doctorate from Harvard
University, he was already on the staff of the U.S. Geological Survey's
astrogeology branch in Flagstaff, Ariz. His job included training
astronauts during simulated lunar field trips. There was only one hole
in his résumé. Schmitt had never learned to fly. In 18 months he earned
his wings, and became a jet plane and lunar landing module pilot. On
Dec. 11, 1972, he and Eugene Cernan landed in the moon's Taurus-Littrow
Valley. On the first of three moonwalks, Schmitt's scientific knowledge
became evident. So did his enthusiasm. His periodic falls stopped hearts
at Mission Control, which feared he would rip his spacesuit and die
instantly. Four years after returning with 244 pounds of moon rocks,
Schmitt was elected U.S. senator from New Mexico. Now chairman of
Albuquerque-based Interlune-Intermars Initiative, he is a leading
advocate for commercializing the moon.--S.C.
Lunar Mining
Samples collected in 1969 by Neil Armstrong during the first lunar landing showed that helium-3 concentrations in lunar soil are at least 13 parts per billion (ppb) by weight. Levels may range from 20 to 30 ppb in undisturbed soils. Quantities as small as 20 ppb may seem too trivial to consider. But at a projected value of $40,000 per ounce, 220 pounds of helium-3 would be worth about $141 million.
Samples collected in 1969 by Neil Armstrong during the first lunar landing showed that helium-3 concentrations in lunar soil are at least 13 parts per billion (ppb) by weight. Levels may range from 20 to 30 ppb in undisturbed soils. Quantities as small as 20 ppb may seem too trivial to consider. But at a projected value of $40,000 per ounce, 220 pounds of helium-3 would be worth about $141 million.
Because
the concentration of helium-3 is extremely low, it would be necessary
to process large amounts of rock and soil to isolate the material.
Digging a patch of lunar surface roughly three-quarters of a square mile
to a depth of about 9 ft. should yield about 220 pounds of
helium-3--enough to power a city the size of Dallas or Detroit for a
year.
Although
considerable lunar soil would have to be processed, the mining costs
would not be high by terrestrial standards. Automated machines might
perform the work. Extracting the isotope would not be particularly
difficult. Heating and agitation release gases trapped in the soil. As
the vapors are cooled to absolute zero, the various gases present
sequentially separate out of the mix. In the final step, special
membranes would separate helium-3 from ordinary helium.
The
total estimated cost for fusion development, rocket development and
starting lunar operations would be about $15 billion. The International
Thermonuclear Reactor Project, with a current estimated cost of $10
billion for a proof-of-concept reactor, is just a small part of the
necessary development of tritium-based fusion and does not include the
problems of commercialization and waste disposal.
The
second-generation approach to controlled fusion power involves
combining deuterium and helium-3. This reaction produces a high-energy
proton (positively charged hydrogen ion) and a helium-4 ion (alpha
particle). The most important potential advantage of this fusion
reaction for power production as well as other applications lies in its
compatibility with the use of electrostatic fields to control fuel ions
and the fusion protons. Protons, as positively charged particles, can be
converted directly into electricity, through use of solid-state
conversion materials as well as other techniques. Potential conversion
efficiencies of 70 percent may be possible, as there is no need to
convert proton energy to heat in order to drive turbine-powered
generators. Fusion power plants operating on deuterium and helium-3
would offer lower capital and operating costs than their competitors due
to less technical complexity, higher conversion efficiency, smaller
size, the absence of radioactive fuel, no air or water pollution, and
only low-level radioactive waste disposal requirements. Recent estimates
suggest that about $6 billion in investment capital will be required to
develop and construct the first helium-3 fusion power plant. Financial
breakeven at today's wholesale electricity prices (5 cents per
kilowatt-hour) would occur after five 1000-megawatt plants were on line,
replacing old conventional plants or meeting new demand.
New Spacecraft
Perhaps the most daunting challenge to mining the moon is designing the spacecraft to carry the hardware and crew to the lunar surface. The Apollo Saturn V spacecraft remains the benchmark for a reliable, heavy-lift moon rocket. Capable of lifting 50 tons to the moon, Saturn V's remain the largest spacecraft ever used. In the 40 years since the spacecraft's development, vast improvements in spacecraft technology have occurred. For an investment of about $5 billion it should be possible to develop a modernized Saturn capable of delivering 100-ton payloads to the lunar surface for less than $1500 per pound.
Perhaps the most daunting challenge to mining the moon is designing the spacecraft to carry the hardware and crew to the lunar surface. The Apollo Saturn V spacecraft remains the benchmark for a reliable, heavy-lift moon rocket. Capable of lifting 50 tons to the moon, Saturn V's remain the largest spacecraft ever used. In the 40 years since the spacecraft's development, vast improvements in spacecraft technology have occurred. For an investment of about $5 billion it should be possible to develop a modernized Saturn capable of delivering 100-ton payloads to the lunar surface for less than $1500 per pound.
Returning
to the moon would be a worthwhile pursuit even if obtaining helium-3
were the only goal. But over time the pioneering venture would pay more
valuable dividends. Settlements established for helium-3 mining would
branch out into other activities that support space exploration. Even
with the next generation of Saturns, it will not be economical to lift
the massive quantities of oxygen, water and structural materials needed
to create permanent human settlements in space. We must acquire the
technical skills to extract these vital materials from locally available
resources. Mining the moon for helium-3 would offer a unique
opportunity to acquire those resources as byproducts. Other
opportunities might be possible through the sale of low-cost access to
space. These additional, launch-related businesses will include
providing services for government-funded lunar and planetary
exploration, astronomical observatories, national defense, and
long-term, on-call protection from the impacts of asteroids and comets.
Space and lunar tourism also will be enabled by the existence of
low-cost, highly reliable rockets.
With
such tremendous business potential, the entrepreneurial private sector
should support a return to the moon, this time to stay. For an
investment of less than $15 billion--about the same as was required for
the 1970s Trans Alaska Pipeline--private enterprise could make permanent
habitation on the moon the next chapter in human history.
Living Off The Land
Exploration of the solar system will be fueled by materials found scattered across asteroids, moons and planets.
Exploration of the solar system will be fueled by materials found scattered across asteroids, moons and planets.
Moon
The discovery of a helium isotope, helium-3, on the moon has given scientists ideas on how to produce electricity far more efficiently than with hydrocarbons or current nuclear plants. The large amounts of energy would come without danger of releasing radioactive substances into the atmosphere.
The discovery of a helium isotope, helium-3, on the moon has given scientists ideas on how to produce electricity far more efficiently than with hydrocarbons or current nuclear plants. The large amounts of energy would come without danger of releasing radioactive substances into the atmosphere.
Mining the lunar surface would not be cheap; the investment would be comparable to building a major transcontinental pipeline.
Mars
Studies conducted by NASA and others have determined that water, rocket propellant and chemicals needed to sustain a human outpost could be manufactured from martian soil and ice caps (right). Future astronauts might set up production plants that expand as others arrive. Eventually, the Mars base could become a resupply base.
Studies conducted by NASA and others have determined that water, rocket propellant and chemicals needed to sustain a human outpost could be manufactured from martian soil and ice caps (right). Future astronauts might set up production plants that expand as others arrive. Eventually, the Mars base could become a resupply base.
Asteroids
Scientists believe these leftovers of the solar system's formation, floating between the orbits of Jupiter and Mars, may contain rare elements and water. Mining these rocks, some as big as mountains, will be neither easy nor cheap. Using technologies previously developed to extract precious materials from the moon or Mars could make asteroids an attractive target, especially for a permanent human colony on the red planet. Astronauts would first practice rendezvous with asteroids. Then, after studying them, crews would return with mining equipment. Excavated ore could be trucked to a martian outpost.
Scientists believe these leftovers of the solar system's formation, floating between the orbits of Jupiter and Mars, may contain rare elements and water. Mining these rocks, some as big as mountains, will be neither easy nor cheap. Using technologies previously developed to extract precious materials from the moon or Mars could make asteroids an attractive target, especially for a permanent human colony on the red planet. Astronauts would first practice rendezvous with asteroids. Then, after studying them, crews would return with mining equipment. Excavated ore could be trucked to a martian outpost.
Titan
As early as next year, we may learn whether Saturn's largest moon, Titan, preserves organic molecules similar to those believed to exist on primeval Earth. The Cassini-Huygens spacecraft is designed to determine whether the atmosphere of Titan indeed contains ammonia and hydrocarbons such as ethane and methane. All these chemicals contain a common element: hydrogen. Extracting this gas in a minus 400°F environment could be easier than on Earth since it would be already liquefied and ready to be used as the most powerful chemical rocket fuel. With organic chemicals as ingredients, a limitless array of synthetic materials could be manufactured.
As early as next year, we may learn whether Saturn's largest moon, Titan, preserves organic molecules similar to those believed to exist on primeval Earth. The Cassini-Huygens spacecraft is designed to determine whether the atmosphere of Titan indeed contains ammonia and hydrocarbons such as ethane and methane. All these chemicals contain a common element: hydrogen. Extracting this gas in a minus 400°F environment could be easier than on Earth since it would be already liquefied and ready to be used as the most powerful chemical rocket fuel. With organic chemicals as ingredients, a limitless array of synthetic materials could be manufactured.
Space Sails
Earthlings first learned about the existence of the solar wind 35 years ago when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin deployed a silver-colored sheet on the moon. Scientists wanted to intercept particles coming from the sun.
Earthlings first learned about the existence of the solar wind 35 years ago when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin deployed a silver-colored sheet on the moon. Scientists wanted to intercept particles coming from the sun.
Taking
advantage of this natural source of energy made perfect sense to some
within the space community. A lightweight sail (above) could be folded
and launched into space. Once in the vacuum of space, the frame attached
to a spacecraft would deploy and the square-mile sail could push a
spacecraft through interplanetary space faster than conventional
propulsion systems, and reach the outer planets in one-fourth the time
spacecraft currently take.--S.C.
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