U.S. Planning Base on Moon To Prepare for Trip to Mars

In this artist's conception, two astronauts on a rover embark on a science mission on the moon with the help of a robotic assistant. All their equipment is to be carried by the two vehicles. (Nasa)

Bush's 2004 "Vision for Space Exploration," by calling for a lunar return and a subsequent Mars mission, set goals, which, if achieved, would keep the United States in the forefront of space exploration for decades.

Since then, mishaps and delays with the space shuttle and the space station programs have shrunk both the moon research budget and the rhetoric promoting the mission.

Instead, NASA Administrator Michael D. Griffin has focused agency attention and resources on the design and construction of a new "crew exploration vehicle" and its attendant rocketry -- the spacecraft that will push U.S. astronauts once again beyond low Earth orbit.

Despite the moon's current low profile, however, NASA continues to plan a lunar mission and to promote the technological advances needed to achieve it. Toups, one of the moon program's designers, said NASA envisions that a lunar presence, once achieved, will begin with two-to-four years of "sorties" to "targeted areas."

These early forays will resemble the six Apollo lunar missions, which ended in 1972. "You have four crew for seven to 10 days," Toups said in a telephone interview. "Then, if you found a site of particular interest, you would want to set up a permanent outpost there."

The south pole is currently the top target. It is a craggy and difficult area, but it is also the likeliest part of the lunar surface to have both permanent sunlight, for electric power, and ice, although many scientists have questions about how much ice there is. Without enough water, mission planners might pick a gentler landscape.

Site selection will mark the end of what McKay calls Apollo-style "camping trips." "There's got to be a lot more autonomy, so we keep it simple," McKay said. "We're going to be on Mars for a long time, and we have to use the moon to think in those terms."

The templates, cited frequently by moon mavens, are the U.S. bases in Antarctica, noteworthy for isolation, extreme environment, limited access, lack of indigenous population and no possibility of survival without extensive logistical support.

"The lunar base is not a 'colony,' " Lee said. " 'Colonization' implies populating the place, and that's not on the plate. This is a research outpost."

Once planners choose a base, the astronauts will immediately need to bring a host of technologies to bear, none of which currently exist. "Power is a big challenge," Toups said. Solar arrays are an obvious answer, but away from the poles 14 days of lunar sunlight are followed by 14 days of darkness, so "how do you handle the dormancy periods?"

Next is the spacesuit. Apollo suits weighed 270 pounds on Earth, a relatively comfortable "felt weight" of 40 to 50 pounds on the moon, but an unacceptable 102 pounds on Mars. "You can't haul that around, bend down or climb hills," Lee said. "Somehow we have to cut the mass of the current spacesuit in half."

And the new suit, unlike the Apollo suits or the current 300-pound shuttle suit, is going to have to be relatively easy to put on and take off, and to be able withstand the dreaded moon dust.

After three days, Apollo astronauts reported that the dust was causing the joints in their suits to jam, "and we're not talking about three outings," Lee said of the next moon missions. "We're talking about once a week for 500 days -- between 70 and 100 spacewalks."

Dealing with dust is also a major concern in building shelters on the lunar surface. Toups said it might be possible to harden the ground by microwaving it, creating a crust "like a tarp when you're camping." Otherwise, the dust pervades everything, and prolonged exposure could even lead to silicosis.

Dust also makes it virtually impossible to use any kind of machinery with ball bearings. Civil engineer Darryl J. Calkins, of the Army Corps of Engineers Cold Regions Research and Engineering Laboratory, warned that the combination of dust, low gravity, temperature swings and the high cost of flying things to the moon is going to define the lunar tool kit in unforeseen ways.

"You can't put a diesel up there; you can't put a 20,000-pound bulldozer up there; and none of our oils or hydraulic fluids are going to survive," Calkins said in a telephone interview. "We may have to go back to the 19th century to find appropriate tools -- use cables, pulleys, levers."

And even then, it will be difficult to level a base site and haul away the fill because there's not enough gravity to give a tractor adequate purchase. Instead, Calkins envisions a device that can "scrape and shave" small amounts of soil and take it away bit by bit.

But in the end, "you have to learn how to do it, with real people," McKay said. "This is hard, but we can learn it. And if we do it right on the moon, we will be able to answer my ultimate question: Can Mars be habitable? I think the answer is 'yes.' "