Six scientists took in a bit of Hawaiian sunshine over the weekend, which was a huge deal, considering it was first time they did it without spacesuits on, following eight isolated months of simulating life on Mars.

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

The crew members lived inside a dome built on the slopes of a dormant volcano so that when they looked out the porthole windows, all they could see were lava fields and mountains.

As a NASA-funded human performance study, the goal was to track members’ emotions in an isolated environment. Monitored by surveillance cameras, body-movement trackers and electronic surveys, the crew provided helpful data that will inform future missions about the potential of communication issues among teams or the likelihood of depression in individuals in such an unique setting.

“Astronauts are very stoic people, very level-headed, and there’s a certain hesitancy to report problems,” said University of Hawaii professor Kim Binsted, principal investigator for the study. “So this is a way for people on the ground to detect cohesion-related problems before they become a real issue.”

Given the challenge of living with six people in such a confined space, the team relieved stress with yoga and workouts that included a solar-powered treadmill and stationary bike—only available on sunny afternoons.

Upon emerging, the crew members devoured all the food items they craved after so many months of freeze-dried goods—watermelon, peaches, croissants, deviled eggs. But there’s a whole lot more they’ve missed.

“To be able to just submerge myself in water for as long as I want, to feel the sun, will be amazing,” said Dunn. “I feel like a ghost.”