Inside the HI-SEAS habitat high up on Hawaii’s Mauna Loa volcano, six scientists are playing make-believe. They are pretending to be the only people on planet Mars. All that separates them from reality is the thin, vinyl fabric covering their dome.

The six-person crew will need to use their imaginations. When they enter or leave their dome, they must stand inside a small doorway for five minutes. That’s meant to simulate how long an airlock doorway would take to seal if the dome was really on Mars. And the mission crew will have to pretend wait when they wish to communicate with pretend Earth. Signals between Mars and Earth take 20 minutes. “Hello, Earth, this is HI-SEAS.” . . . wait, wait, wait, . . . “Hello, HI-SEAS, this is Earth.” . . . wait, wait, wait.

The mock Mars mission may seem strange. But really, their home for eight months is pretty comfortable. It’s a lot like living in an ordinary, small, suburban house—if that house was a very cool geodesic dome!

Dome Facts:

Water: limited. Use only a little bit!

Solar heated water: for showers in evening

Heat: water radiators

Cooling: not necessary at 8,000 feet elevation

Toilets: waterless, composting—decay waste (and 20 rolls of toilet paper per month!)

Power: solar arrays, using battery storage overnight and a fuel cell as backup

Size: The circle of the dome measures 36 feet across. The 1st floor has 993 square feet of useable space. The 2nd floor loft is 424 square feet.