A sunlit crescent of Earth seen from the moon.
The first trips will be Apollo-like sorties, brief visits to test techniques and equipment and to begin building the outpost. Eventually the base will include living quarters, a launchpad, a storage facility for fuel and supplies, and a power plant. By 2024, NASA experts expect to have enough infrastructure to support a permanent human presence with four astronauts rotating every six months, the same length of a stay as on the International Space Station.
Setting up a permanent outpost on the moon would, in many respects, be more daunting than putting an outpost on Mars. Like Earth, Mars has an atmosphere, weather, and seasons, and its gravity is one-third of Earth’s. The moon has one-sixth of Earth’s gravity, no atmosphere, and a merciless and unending barrage of radiation and micrometeorites. Some scientists argue that if going to Mars is the ultimate goal, there’s no point in going to the moon.
But if the goal is learning about long-term stays in space, going to the moon provides excellent instruction. Space station astronauts are in low Earth orbit, only 224 miles from safety. Moon astronauts will be three days from help, and Mars astronauts will, at best, be months away—virtually alone after liftoff. The explorers will not only have to learn to live in reduced gravity in cramped spaces for prolonged periods, as in the carefully calibrated indoor environment of the space station, but they must also work outside for extended periods in potentially lethal environments they cannot control. They must make consumables like oxygen, recycle them, and recycle waste. They must be able to maintain their equipment, knowing that not only their scientific mission but their very lives may depend on their repairs. And they must be able to cope with sickness, set broken bones, perform emergency appendectomies, and, in the worst of circumstances, watch a comrade die from injury or blood loss, knowing that he or she could easily have survived with timely treatment at a terrestrial hospital.
Desert RATS members simulate collecting lunar
soil during a
2005 field test in Arizona (top). A
mock lunar habitat at the Johnson
Space Center
in Houston is designed to house four astronauts
(below).
Coping with these challenges will require an attitude adjustment and a lot of practice, and screwups are better handled closer to home. Former astronaut and U.S. senator Harrison Schmitt, the last man to walk on the moon, told delegates at a NASA-sponsored moon conference last year that humanity needed to “redevelop a deep space operational structure and discipline.” Others describe the situation more bluntly. NASA, grown skittish because of the losses of space shuttles Challenger and Columbia, has become too risk-averse.
“There are things we have to decide,” says University of Tennessee geochemist Lawrence Taylor, a leading moon scientist. “There’s going to be a hazard, and if we think it’s dangerous to go to the moon, what about Mars? You just can’t bail out and go home.”
The abrasive regolith is just one aspect of the moon’s harsh
environment. The equator promises relatively happy landings on
relatively smooth surfaces, but it also guarantees temperatures that
exceed 250 degrees Fahrenheit during the day and plummet below –240°F
during the night—and both day and night last 14 Earth days. The Apollo
astronauts did most of what they did during the lunar equivalent of
early morning and forenoon—light enough to see but not as hot.
Climate is the main reason NASA announced last December that it would build its outpost near one of the lunar poles. The current favorite spot is the edge of Shackleton Crater at the moon’s south pole, which is expected to feature “moderate” temperatures, between –50°F and 50°F. Shackleton also has the important advantage of being in sunlight—albeit weak sunlight—for up to 80 percent of the year. Abundant light will be crucial for generating electricity. If the base were built at the lunar equator, it would be in darkness for half of every month. During that time, solar-collecting arrays would be useless.
Another important attraction of the moon’s poles is the possible presence of useful natural resources. Lunar orbiters in the 1990s detected concentrations of hydrogen, a potential resource for rocket fuel. Currently no one knows how much there is or what form it takes. Some scientists suspect that a comet may have sideswiped the moon long ago, leaving water ice buried in permanently shadowed craters. Identifying the source of the hydrogen is a key goal for the robotic missions that will precede the next landing by humans. The downside of a polar landing is that the landscape there is craggier and more forbidding than at the moon’s midline, which makes landings more challenging. Nonetheless, NASA officials believe the advantages at the south pole outweigh the risks.
