Scientists re-emerge after a year-long Mars simulation project.

After a year, four scientists in the United States on Saturday ended an experiment that simulated life on Mars. To loud applause, the four volunteers left NASA-built Mars Dune Alpha, where they had spent the past 378 days completely isolated from the outside world. The 160-square-meter structure at the Johnson Space Center in Houston was designed to mimic conditions on the Red Planet. The habitat is a 3D-printed facility, complete with bedrooms, a gym, common areas, and a vertical farm for growing food. The structure also features an outdoor area, separated by an airlock. The space is filled with red sand and is where the team donned suits to conduct their "Marswalks."

Anca Selariu, Ross Brockwell, Nathan Jones, and team leader Kelly Haston spent the last year growing vegetables, conducting "Marswalks," and operating under "additional stressors" such as communication delays with "Earth," including their families; isolation; and confinement. As they left the habitat on Saturday, the four volunteers were visibly emotional. Brockwell emphasized the mission's collaborative spirit and its potential benefits for humanity.

The mission was the first in a series called Crew Health and Performance Exploration Analog (CHAPEA), aimed at preparing NASA to send humans back to the moon and eventually to Mars. Julie Kramer, NASA's director of engineering, highlighted the project's role in making future Mars missions safer. Additional CHAPEA missions are planned for 2025 and 2027.