HOUSTON, Texas -- U.S. space exploration plans came into sharper focus withNASA's announcement that it intends to lay the first pieces of an internationallunar 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 explorationplan--highly tentative though it may be--was a small but important step towardinternational collaboration, experts here said.
NASA's proposed lunar architecture--essentially, a rough planto scout the Moon with robotic trailblazers before sending astronauts and moremachines to lay a foundation for a permanent outpost at one of the lunar poles--isthe United States' response to an overarching Global Exploration Strategy thatemerged this year from a series of international meetings involving 14 spaceagencies and more than 1,000 people including government officials, businessexecutives, scientists and other experts, NASA Deputy Administrator Shana Dalesaid during a Dec. 4 press conference here.
Dale and other NASA officials revealed more details of theproposed lunar architecture--and the opportunities they saw for internationalparticipation--over the next two days at the 2nd Space Exploration Conferencehere organized by the American Institute of Aeronautics and Astronautics.
"First, we see the Moon not as a brief rendezvous, but as anoutpost," Dale said. "Our objective is to create an enduring, sustainable humanand robotic presence that will open up vastly greater opportunities forscience, 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 evolveand allow the journey to continue to Mars and to other destinations."
Doug Cooke, NASA's deputy associate administrator forexploration systems, continued that theme during the conference's paneldiscussions. He said NASA is very interested in getting other nations to jointhe United States on the Moon "so we can all accomplish more than we could onour own."
Cooke said that while NASA intends to field the necessarytransportation systems and establish the essential elements of a human outpostat one of the lunar poles, there is plenty of work to be done by others toaugment 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 advantagesover equatorial locations, including longer extended periods of sunlight, moremoderate temperature swings, and the tantalizing prospect that the poles mightharbor stores of water ice in permanently shadowed craters.
The job of describing how NASA foresees the first five yearsof human lunar expeditions unfolding was left to Tony Lavoie, a Marshall SpaceFlight Center official who leads the agency's Lunar Architecture Team. Thenotional plan produced by Lavoie's team would enable six-month stays withinfive years by making sure every lunar landing leaves behind at least somecritical piece of infrastructure.
An important element of this approach, Lavoie said, entailsdesigning a crew and cargo lander that minimizes the size of its ascent anddescent modules in order to maximize the amount of equipment it can put on theMoon's surface. Notionally, NASA is looking at 6,000 kilograms of landed mass,he said.
Lavoie said his team chose the Shackleton Crater at thesouth pole because NASA currently knows of no better polar location, but thatcould easily change once the Lunar Reconnaissance Orbiter, due to launch inlate 2008, has a chance to report back.
Most of what NASA knows about the lunar poles comes from the1998 Lunar Prospector mission. While Lunar Prospector overflew both the northand south poles during its one-year mission, the satellite saw more of the southpole during winter, Lavoie said, giving NASA a better feel for conditionsthere.
Regardless of whether NASA heads north or south, the polesare attractive in part because they are more thermally moderate than theequatorial regions, where temperature swings of plus or minus 250 degrees wouldput added stress on equipment and machines. Lavoie said the higher percentageof sunlight at the poles--the edge of Shackleton Crater, for example, ispermanently in sunlight at least 75 percent of the time--makes it possible forNASA 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 themission to deliver an unpressurized rover and a solar power unit producingperhaps 6 kilowatts of electricity.
When astronauts finally arrive, they would stay for sevendays and bring with them a habitat and other equipment that they would leavebehind. A second mission later that year would deliver additionalpower-generation units, perhaps another unpressurized rover and otherstill-to-be determined infrastructure.
The focus of the second year, Lavoie said, would be puttingadditional habitation modules, power-generators and other infrastructure inplace to support 14-day stays starting in the third year. The build up wouldcontinue with two missions a year, enabling 30-day stays with the arrival of afourth 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 growingoutpost.
A key focus of the first five years, under the plan NASAlaid out, would be to demonstrate various forms of in-situ resourceutilization, or ISRU, finding a way to use lander byproducts and even astronautwaste to support surface operations.
But because ISRU is "in its infancy," as Lavoie put it, NASAwill not rely on it for anything until it is proven.
And while NASA plans to emplace the necessary infrastructureto support extended expeditions, Lavoie said one of the advantages of theoutpost approach is that there is plenty of room for other agencies or entitiesto add to the outpost or augment its capabilities by, for example, deliveringadditional ISRU systems or communications assets.
A lengthy list of needed capabilities for a lunar outpostthat NASA presented during the conference was remarkable for the limited amountof items the United States staked out for itself, several conference attendeesremarked.
The response to NASA's plans from international space agencyofficials in attendance was positive. A number of these officials praised NASAfor engaging the world's space agencies early in the process, a contrast, theysaid, to how the U.S. planned the international space station.
"The overall approach was very un-NASA," one non-U.S. spaceagency official said, meaning it as a compliment.
Others said they were very pleased that NASA presented itsplans in enough detail to allow them go back home and engage their governmentsin fruitful discussions about how their agencies could participate.
John Logsdon, the director of George Washington University'sSpace Policy Institute, said there was "high level of enthusiasm" among theinternationals at the conference both for the overall process and the endproduct NASA unveiled.
"With the announcement that this is leading toward apermanent outpost, that gives everybody a common objective to plan for," hesaid.
Space agency representatives were due to meet Dec. 8 at theLunar and Planetary Institute here to craft and issue a common statement on theGlobal Exploration Strategy.
More international meetings are on tap for 2007, accordingto NASA. The agency also plans to get started early next year on an initialMars architecture. Cooke said the primary purpose of doing a Mars architecturenow is to make sure it "synchs up" with NASA's lunar plans.
Logsdon predicted that it would be several years before anotheragency announced concrete plans to join the United States on the Moon. But hesaid he would expect to see an agreement on the framework for coordination andcooperation perhaps as late 2007.
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