NASA's four-person Mars simulation crew ends 378 days in isolation

Four NASA volunteers emerged on Oct. 31 from a 1,700-square-foot, 3D-printed habitat at Johnson Space Center in Houston, completing a 378-day simulation of a crewed Mars surface mission. The crew — commander and test pilot Ross Elder, medical officer Ellen Ellis, flight engineer James Spicer and science officer Matthew Montgomery — had entered the habitat, known as Mars Dune Alpha, on Oct. 19, 2025, as part of the second mission in NASA's Crew Health and Performance Exploration Analog program, or CHAPEA, according to the agency's official mission recap.

For more than a year, the crew lived without windows and without real-time contact with family or friends; communication delays with the outside world ran up to 22 minutes each way to mimic the lag of an actual Mars mission. They conducted simulated "Marswalks," operated a drone and rover from inside the habitat to survey terrain and collect rock samples, grew crops hydroponically, and carried out routine habitat maintenance and exercise on a fixed schedule, all while working with deliberately limited food, water and other supplies.

"The real magic... has been the privilege"

Johnson Space Center Director Vanessa Wyche said the crew's "work means more than completing a mission," according to NASA's account, while astronaut Jack Hathaway said the yearlong isolation "required immense physiological and psychological strength, teamwork, and human grit." Elder, the commander, said "the real magic has been the privilege and pleasure of seeing everyone come together," and flight engineer Spicer said the crew managed to make the year "not a chore, but a joy."

No specific findings have been released yet. NASA says the crew will spend two weeks on post-mission medical and psychological evaluations and debriefs before researchers begin analyzing the health and performance data in earnest. That data is meant to help the agency weigh trade-offs between health risks and practical limits for real long-duration missions, including a proposed lunar outpost near the Moon's south pole and eventual crewed trips to Mars. NASA's first CHAPEA mission, with a different four-person crew, concluded in July 2024.

A new astronaut class, meanwhile

The CHAPEA conclusion comes as NASA separately opens its next round of astronaut recruitment. In a news release published this month, the agency said applications close at 11:59 p.m. EST on Dec. 3 and can be filed through USAJobs. Candidates must be US citizens with a relevant master's degree or equivalent experience — engineering, biological or physical science, computer science, medicine or completed test-pilot training — plus at least three years of related professional experience, or qualifying flight hours for pilots. NASA Administrator Jared Isaacman called it "an extraordinary time to join NASA's astronaut corps." The agency's last recruitment round, in 2024, drew more than 8,000 applications for 10 spots; final selections from this round are expected in late 2027, with training beginning in early 2028.