Because the journey to Mars takes so long (about six months each way, assuming we can ever get there at all) astronauts will have to hunker down for nearly two years while they wait for the planets to realign for a (relatively) speedy trip home. Considering the fact that our longest human spaceflight endeavors have simply been stays on the International Space Station or the Soviet station Mir, NASA has a lot of things to figure out before we can stomp all over the Red Planet.
Enter Mauna Loa: The barren Hawaiian volcano is about as Martian as Earth terrain gets, and NASA's 36-foot-wide domed habitat is a good approximation of the kind of thing we could set up on Mars. Previous simulations on Mauna Loa have maxed out at eight months long. One Russian simulation in another location kept astronauts in isolation for a year and a half, but they were essentially trapped inside a "spacecraft" with no way out — they didn't venture onto the "alien" surface, as the astronauts in the Hawaiian experiment did.
That's not to say that isolation alone isn't worthy of study. In addition to having to put up with crewmates for something like three years — with only limited, delayed and purely digital contact with other humans — astronauts who journey to Mars will have to deal with the psychological effects of spaceflight (darkness, stale air, bad food, cramped quarters) followed immediately by the psychological effects of landing on an alien world (TBD).
"It is kind of like having roommates that just are always there and you can never escape them," mission commander and soil expert Carmel Johnston told the BBC. "So I'm sure some people can imagine what that is like, and if you can't then just imagine never being able to get away from anybody," she said.
How long has it been? A year and a day. Once again, I’ll be able to walk down the street. To watch a cat curl up in a window; see a dog lying in the sun with such stillness that you wonder if he’s still alive — and then he bolts upright at the sound of a passing care or twitches an ear, and you laugh at yourself for wondering. I’ll be able to see the stars without cleaning my faceplate twice (once inside and once out). I’ll be able to answer the phone: Hello? Hello! You do these things everyday without thinking about them. It’s been 366 days since I answered a phone.
It's hard to imagine how much more profound those feelings will be when astronauts experience a full-length mission. Let alone one that's actually, you know, in space.
But HI-SEAS did more than just put a bunch of people in a box for a year. Gifford and Johnston (along with German physicist Christiane Heinicke, engineer Andrzej Stewart, French astrobiologist Cyprien Verseux and architect Tristan Bassingthwaighte) had to tackle unforeseen "emergencies" and equipment malfunctions without the ability to get physical help from folks on the outside. In one incident, they had to spend two weeks showering with buckets while they tried to puzzle out what had gone wrong with the habitat's plumbing system.
Meanwhile, the group practiced pretend jaunts out onto the Martian surface while bedecked in spacesuits and lived only on food that could be carried to Mars and stored for years at a time.
Despite these challenges, it certainly sounds like boredom was the biggest concern during the length of the mission. But it wasn't all bad.
"I'm a military brat, I grew up with my dad in the Air Force, and where you live becomes home after a while, and I'm going to miss the place," Andrzej Stewart told Space.com.