Science: A home from home

Nasa wants to establish a Moon base. But what would it be like to live there?

"Beautiful!" exclaimed Buzz Aldrin, the second man to walk on the Moon, as he stood for the first time in his spacesuit on the lunar surface. "Beautiful!" And then he added, "Magnificent desolation." After that, he recalls, there was no more time to record impressions: he had to get to work.

Now, it looks like we might be able to take more careful stock of that "magnificent desolation". The excitement about last week's announcement by the US space agency Nasa, that there is water on the Moon, has infected the space industry. People inside and outside Nasa are talking about hurrying back to the place that we thought we had left for good in December 1972. "Human life could expand to the moon," said Alan Binder, the jubilant lead scientist for the Lunar Prospector spacecraft, as he revealed the findings.

With water available, he said, it would be possible to start building a moon base in eight to 10 years and have a partially self-supporting colony within 15 years. "We could do it even faster if we pushed it," Binder said. The water is now available and the technology can be developed, but there would have to be a national decision to tackle the project.

Certainly, the political fight will be fascinating, at least to politicians. But of more interest to the average person is the question: what's it actually like to live and work on the Moon? Would you be a superhuman? Would you go mad?

Actually, the thing that the astronauts from the six Apollo missions which landed there remember is the dust. Produced by millennia of meteor and comet impacts, it has been ground down into tinier and tinier particles. It's all over the Moon. It's also one of the most annoying things you encounter there.

Eugene Cernan, commander of the last manned Moon mission, Apollo 17, said: "The dust is like graphite, but graphite lubricates, whereas lunar dust makes things stick together. It gets into your space suits... It's so fine it even gets into the pores of your skin. It took me weeks after my return to get rid of the last traces of it."

It might seem surprising that a $10m (pounds 6.25m) spacesuit designed to protect against the hostile vacuum and cold of space could let in something from outside. But it's the nature of such fine materials that they behave almost like a fluid, inevitably penetrating the tiniest of flaws. Anybody who doesn't like itching or feeling grimy would be well-advised not to volunteer for the Lunar Laboratory.

However, it takes a few days for the effects of the dust to be noticeable. By contrast, the first thing that hits any lunar visitor is the peculiar effect of the satellite's size on range estimation.

"We had difficulties in perception of distance," recalled Neil Armstrong, the man who in July 1969 became the first to walk on the Moon. "For example, from the cockpit of the lunar module we judged our television camera to be only 50 or 60ft away. Yet we knew we had pulled it out to the extent of a 100ft cable.

"Similarly, we had trouble guessing how far the hills on the horizon might be away from us. The peculiar phenomenon is the closeness of the horizon, due to the greater curvature of the Moon's surface - four times greater than the Earth. Also, it's an irregular surface, with crater rims overlying other crater rims."

Added to that is the looming shape of the Earth, which naturally appears far larger in the Moon's sky than vice-versa. Even during the "day" the lunar sky is black (there is nothing to scatter the sun's rays, as on Earth) and Cernan recalled that "you can see stars if you concentrate very hard".

The real separation comes on the night side, which Cernan orbited: "You are probably in the blackest blackness anyone can imagine. You're out of sight of the Earth, and you can't even see the Moon below you. All you can see are hundreds and hundreds of stars."

It's once you start moving that the gravity, one-sixth that of Earth, becomes apparent. Armstrong and Aldrin, as the first astronauts, were cautious about moving about. But the later teams became increasingly confident, until they were literally throwing themselves into their work, timing leaps and movements as well as could be expected for people who only spent at most a few days there.

Extended periods on the Moon would certainly take their toll. Even normal bodily functions are complicated by wearing a spacesuit. How did the Apollo astronauts do it? "With great care," replied Aldrin. "Seriously, we used bags and hoses and personal wipes. The details are left to the imagination, but there's really nothing gory in the reality. Sort of like a long camping trip, you're glad to have a hot shower at the end."

That hot shower might be in a permanent lunar base, though it would have to be very solid to withstand small meteor impacts (against a large one, it wouldn't have a chance). It would have to be exceptionally well-insulated, as would the spacesuits used by future Moon explorers prospecting for ice.

The real problem, explains the astronomer Patrick Moore, is that the ice must lie at the bottom of deep craters which never see sunlight - or else it would boil away into the vacuum of space.

"The walls of the craters are thousands of feet high," he explains. "That makes it immensely difficult to explore them. The fact that they're at the poles as well, which are very hard to reach, adds to your problems." While the lunar rover seemed a success, that travelled over comparatively flat, solid ground. Ascending the sides of a lunar crater in temperatures that might be 100 degrees below zero is the sort of task that makes climbing Everest look easy. Though you and your equipment weigh six times less than on Earth, everything has the same inertia as before. Jump, and you'll still have to bear the impact when you land. And a huge falling rock will still crush you. The crash of the Mir space station with its cargo ship last June demonstrates that taking away weight does not remove hazards.

Added to that are the likely health problems of an extended stay. In lower gravity, bones and muscles tend to lose mass, as has been repeatedly demonstrated with occupants of space stations. There might be other, as yet unknown, long-term effects of low gravity.

Furthermore, it's important not to discount the psychological effects of being in a remote place where it's possible you would never see your home planet from one "day" to the next. Scientists on Antarctic missions have recorded how the slightest physical or psychological defect in your companions becomes magnified, and increasingly annoying. While space training can prevent most of that, some frustration with one's companions is inevitable.

And even when you return to terra firma, the pyschological effects of such a trip can linger. Aldrin admits: "I went from having reached the pinnacle in man's space exploration to having effectively no where to go." He struggled with alcoholism and substance abuse, but dragged himself out of what he now calls "a difficult mid-life transition." The Moon, and the idea of exploration, has once again given his life purpose: he has written science-fiction books around the theme of living on the Moon, and appears on TV adverts touting the pleasures to come when we'll holiday there.