It's part of the ongoing Hawaii Space Exploration Analog and Simulation — or HI-SEAS — experiment.
Essentially, it's to help NASA figure out how isolation and lack of privacy for long periods of time affects people.
Useful information for, you know, any future astronauts spending long stretches of time traveling to and living on the surface of Mars.
And as previous missions have shown, the volunteers don't get much privacy in the dome. Like, none at all. But that's also kind of the point.
And they do get to go outside every now and then. Just as if they were actually on Mars.
Except they're actually on Hawaii, of course. The research project was started by the University of Hawaii at Manoa in 2013 and is funded by NASA.
This mission's team consists of a French astrobiologist, German physicist and four Americans — including a pilot, an architect, a journalist and a soil scientist. Let's hope they all don't hate each other come this time next August.