HOUSTON, Texas -- U.S. space exploration plans came into sharper focus with
NASA's announcement that it intends to lay the first pieces of an international
lunar outpost at the Moon's north or south poles starting around 2020.
For spacefaring nations considering joining the United
States on the Moon, NASA's unveiling of a fairly detailed lunar exploration
plan--highly tentative though it may be--was a small but important step toward
international collaboration, experts here said.
NASA's proposed lunar architecture--essentially, a rough plan
to scout the Moon with robotic trailblazers before sending astronauts and more
machines to lay a foundation for a permanent outpost at one of the lunar poles--is
the United States' response to an overarching Global Exploration Strategy that
emerged this year from a series of international meetings involving 14 space
agencies and more than 1,000 people including government officials, business
executives, scientists and other experts, NASA Deputy Administrator Shana Dale
said during a Dec. 4 press conference here.
Dale and other NASA officials revealed more details of the
proposed lunar architecture--and the opportunities they saw for international
participation--over the next two days at the 2nd Space Exploration Conference
here organized by the American Institute of Aeronautics and Astronautics.
"First, we see the Moon not as a brief rendezvous, but as an
outpost," Dale said. "Our objective is to create an enduring, sustainable human
and robotic presence that will open up vastly greater opportunities for
science, research and technological development."
Dale described NASA's lunar plan as "an open architecture"
that other nations and commercial interests could add to "in order to evolve
and allow the journey to continue to Mars and to other destinations."
Doug Cooke, NASA's deputy associate administrator for
exploration systems, continued that theme during the conference's panel
discussions. He said NASA is very interested in getting other nations to join
the United States on the Moon "so we can all accomplish more than we could on
our own."
Cooke said that while NASA intends to field the necessary
transportation systems and establish the essential elements of a human outpost
at one of the lunar poles, there is plenty of work to be done by others to
augment and expand the settlement.
A decision was made to locate the base at one of the poles,
Cooke said, because it offers a number of operational and scientific advantages
over equatorial locations, including longer extended periods of sunlight, more
moderate temperature swings, and the tantalizing prospect that the poles might
harbor stores of water ice in permanently shadowed craters.
The job of describing how NASA foresees the first five years
of human lunar expeditions unfolding was left to Tony Lavoie, a Marshall Space
Flight Center official who leads the agency's Lunar Architecture Team. The
notional plan produced by Lavoie's team would enable six-month stays within
five years by making sure every lunar landing leaves behind at least some
critical piece of infrastructure.
An important element of this approach, Lavoie said, entails
designing a crew and cargo lander that minimizes the size of its ascent and
descent modules in order to maximize the amount of equipment it can put on the
Moon's surface. Notionally, NASA is looking at 6,000 kilograms of landed mass,
he said.
Lavoie said his team chose the Shackleton Crater at the
south pole because NASA currently knows of no better polar location, but that
could easily change once the Lunar Reconnaissance Orbiter, due to launch in
late 2008, has a chance to report back.
Most of what NASA knows about the lunar poles comes from the
1998 Lunar Prospector mission. While Lunar Prospector overflew both the north
and south poles during its one-year mission, the satellite saw more of the south
pole during winter, Lavoie said, giving NASA a better feel for conditions
there.
Regardless of whether NASA heads north or south, the poles
are attractive in part because they are more thermally moderate than the
equatorial regions, where temperature swings of plus or minus 250 degrees would
put added stress on equipment and machines. Lavoie said the higher percentage
of sunlight at the poles--the edge of Shackleton Crater, for example, is
permanently in sunlight at least 75 percent of the time--makes it possible for
NASA to consider solar power and fuel cells as an alternative to nuclear power.
Before the first astronauts are sent back to the Moon,
Lavoie said, NASA envisions conducting an unmanned test of the lander, using the
mission to deliver an unpressurized rover and a solar power unit producing
perhaps 6 kilowatts of electricity.
When astronauts finally arrive, they would stay for seven
days and bring with them a habitat and other equipment that they would leave
behind. A second mission later that year would deliver additional
power-generation units, perhaps another unpressurized rover and other
still-to-be determined infrastructure.
The focus of the second year, Lavoie said, would be putting
additional habitation modules, power-generators and other infrastructure in
place to support 14-day stays starting in the third year. The build up would
continue with two missions a year, enabling 30-day stays with the arrival of a
fourth habitation module at the beginning of year four.
By the end of fifth year of human expeditions, Lavoie said,
NASA would anticipate being ready to support six-month stays at the growing
outpost.
A key focus of the first five years, under the plan NASA
laid out, would be to demonstrate various forms of in-situ resource
utilization, or ISRU, finding a way to use lander byproducts and even astronaut
waste to support surface operations.
But because ISRU is "in its infancy," as Lavoie put it, NASA
will not rely on it for anything until it is proven.
And while NASA plans to emplace the necessary infrastructure
to support extended expeditions, Lavoie said one of the advantages of the
outpost approach is that there is plenty of room for other agencies or entities
to add to the outpost or augment its capabilities by, for example, delivering
additional ISRU systems or communications assets.
A lengthy list of needed capabilities for a lunar outpost
that NASA presented during the conference was remarkable for the limited amount
of items the United States staked out for itself, several conference attendees
remarked.
The response to NASA's plans from international space agency
officials in attendance was positive. A number of these officials praised NASA
for engaging the world's space agencies early in the process, a contrast, they
said, to how the U.S. planned the international space station.
"The overall approach was very un-NASA," one non-U.S. space
agency official said, meaning it as a compliment.
Others said they were very pleased that NASA presented its
plans in enough detail to allow them go back home and engage their governments
in fruitful discussions about how their agencies could participate.
John Logsdon, the director of George Washington University's
Space Policy Institute, said there was "high level of enthusiasm" among the
internationals at the conference both for the overall process and the end
product NASA unveiled.
"With the announcement that this is leading toward a
permanent outpost, that gives everybody a common objective to plan for," he
said.
Space agency representatives were due to meet Dec. 8 at the
Lunar and Planetary Institute here to craft and issue a common statement on the
Global Exploration Strategy.
More international meetings are on tap for 2007, according
to NASA. The agency also plans to get started early next year on an initial
Mars architecture. Cooke said the primary purpose of doing a Mars architecture
now is to make sure it "synchs up" with NASA's lunar plans.
Logsdon predicted that it would be several years before another
agency announced concrete plans to join the United States on the Moon. But he
said he would expect to see an agreement on the framework for coordination and
cooperation perhaps as late 2007.
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