Six astronauts spent about 8 months in a simulated Mars mission in an airtight dome on a Hawaii volcano. They just felt the fresh air again for the first time in nearly a year:

“When we first walked out the door, it was scary not to have a suit on,” said Dunn, 27, a doctoral candidate at Purdue University. “We’ve been pretending for so long.”

The dome’s volcanic location, silence and its simulated airlock seal provided an atmosphere similar to space. Looking out the dome’s porthole windows, all the scientists could see were lava fields and mountains, said University of Hawaii professor Kim Binsted, principal investigator for the study, in a statement.

. . .

“When you’re having a good day its fine, it’s fun. You have friends around to share in the enjoyment of a good day,” Dunn said. “But if you have a bad day, it’s really tough to be in a confined environment. You can’t get out and go for a walk … it’s constantly witnessed by everyone.”

The astronauts lived together in a thousand square feet of space, ate mostly freeze-dried chili and other long-term shelf-stable foods, and got to enjoy only eight minutes of shower time once a week. Which seems miserable.

But this eight-month stay was not even as long as it would take to get to Mars. A group of astronauts simulated that in 2011. It took 520 days.

Which leads me to the conclusion that a Mars mission is not going to happen anytime soon. I wonder when NASA will give up on its current space station model: with freeze-dried foods, filtered blended bottled air, filtered distilled water, etc. These methods just aren’t sustainable in the long term. They erode human health in no time at all.

There are other available models for traveling and living in space. The story of Biosphere 2 is a fascinating example. For two years, seven people lived in an air-locked bio-dome. The dome was meant to produce all of its own oxygen from plants, soil-based organisms filtered the air which was pumped through the ground, waste and water was recycled, and food was grown or raised within the facility. The two-year experiment was haunted by complications, almost all of which were interpersonal in nature. While most of the seven exited the bio-dome basically healthy in purely material terms, after two years, they just didn’t like each other. So in the end, it’s unclear whether the experiment was doomed by bad science or just bad blood.

It would be pretty awesome if NASA picked up bio-dome research and tried creating a space station that sustained human life over the long term. In the end, I don’t think anything less than that would work for a viable Mars mission.