Six "crew members" have returned to normal life after spending a full year doing a simulated Mars mission in Hawaii. For the project, the crew had to live as if they were living in a real Martian habitat, enduring all of the challenges that come with residing on another planet. That entailed living in isolation on Hawaii’s Mauna Loa volcano, where the crew had limited communication with friends and family — and they couldn’t go outside without a spacesuit on.

The volunteers were part of the fourth mission for HI-SEAS, or the Hawaii Space Exploration Analog and Simulation, conducted by the University of Hawaii. A NASA-funded project, HI-SEAS challenges people to live for long periods of time in a Mars-like habitat here on Earth. The goal is to better understand the physical and psychological challenges of living with a small group of people for so long, as well as the difficulties of being cut off from loved ones.

This most recent mission began on August 29th, 2015, when the six-member crew entered the HI-SEAS habitat. A two-story dome, the habitat is located at an elevation of 8,000 feet on the slope of Mauna Loa. Its 993 square-foot ground floor includes a kitchen, a lab, bathroom supplies, and areas to exercise and relax. The upper floor, which is just 424 square feet, holds all six bedrooms and another half-bathroom. Attached to the dome is an additional workshop, converted from a sleep container.

The HI-SEAS kitchen. (HI-SEAS/Sian)

During their time inside the habitat, the crew members kept the outside world updated on their exploits. And the past year wasn’t exactly smooth sailing for the HI-SEAS team. Apparently, there was a malfunction with the bathroom, forcing the crew to take baths with buckets for a couple weeks, according to NBC News. And most of the crew agreed that a year within the habitat became extremely monotonous. "More than anything it’s just kind of keeping yourself from getting bored and dealing with cabin fever," said crew member Tristan Bassingthwaighte during an interview on Periscope. Multiple people on the team suggested future HI-SEAS crew members bring lots of books.

The team finally left the habitat — sans spacesuits — on Sunday around 3PM ET. Their experiment marked the longest HI-SEAS mission that’s been conducted so far. The first two missions lasted around four months each, while the third mission was eight months in length.

Now that this latest mission is over, HI-SEAS is ready to go again. The initiative is already recruiting members to participate in the next two missions, which will last both last for eight months each. Mission A will last from January through September of 2017, while Mission B will last for the same months in 2018. Check out the HI-SEAS recruitment solicitation to see if you have what it takes.