AN ASTRONAUT'S FIRST impression of Mars will be strongly dependent on the time of year when he or she lands. "Winter's my favourite time because the skies are so clear," says Squyres. "You get crisp views with beautiful, wispy clouds. Summer is hazy. It's also when you could get a global dust storm."
Experiencing a Martian dust storm wouldn't be like being flayed by a Saharan sandstorm. It would probably be more like finding yourself trapped in thick red-brown smog. "At its worst, you can't really tell where the Sun is," Squyres says. "I think the greatest effect would be psychological. It would get hazy and dim for months. That could get to you after a while," he speculates.
And then there are the dust devils. Squyres likes to refer to them as "a summertime phenomenon and a lunchtime phenomenon". Translation: they kick up at about 10 am, and last until 2 or 3 pm. They're not quite tornadoes – though they might pack enough punch to carry off loose sheets of plastic –and they have the beneficial side effect of blowing dust off solar panels. "They're one of my favourite things on Mars," he says. That's because Mars is normally very static. "You go along and kick a rock, and that rock may have been there for a billion years." With dust devils, "you actually get to see something move."
Once the initial excitement subsides, however, astronauts may feel very isolated. Earth will be a blue speck, about as bright as Venus appears from Earth, simultaneously reminding them of home and telling them just how far away it is.
On the other hand, in the days before radio, explorers survived worse isolation in the Arctic and Antarctic. "Plus, as scientists, you are on an alien world that's never been explored," says Squyres. "I don't think boredom is going to be an issue."
Gravity, however, may continue to be a problem. "We have no experience with 38 per cent Earth gravity," says Robinson. "[But] we know perfectly well that microgravity is bad for you and you have to exercise your butt off to counteract it." One of the advantages of going to the Moon first is that by the time we get to Mars, we'll have had lots of practice coping with even lighter gravity. It's likely, though, that the health-conscious will need long, daily stints on treadmills or exercise bikes.
The first explorers will live in their landers, which Zubrin envisions as two-storey tuna cans on stilts, capable of housing four to six people. His group has even tested such structures in the Utah desert and on Canada's Devon Island, whose sere, Arctic plains are among Earth's closest analogues to Mars. The mock-up habitats are 8.2 metres in diameter, giving them a bit more than 211 square metres of living and workspace: about the size of a large flat or small townhouse. The upper deck is split between tiny bedrooms and a common living/kitchen/dining area. The lower deck has a workroom, bathroom, and utilities. Despite the cramped quarters, Zubrin says, "We found them quite liveable."
The habitats even have mock landing legs and an airlock. Crews living in the habitats have simulated Mars conditions in which they can't go outside without putting on a "spacesuit," and communications with the outside are by email with a built-in time lag to simulate the speed-of-light delay in radioing from Mars to Earth. "If you've got a question, you'll wait at leat 45 minutes for the reply," wrote science fiction author Wil McCarthy, who described a two-week stint in the Utah habitat in a 2005 article for Analog science fiction magazine.
Because the habitats aren't return vehicles, they will gradually accumulate on Mars, providing nuclei for expanding bases, or possibly strings of yurt-like huts within rover-range of each other.
