CHAPEA Crew Ends 378 Days Inside Simulated Mars Habitat

Four volunteers walked out of a simulated Mars habitat in Houston on October 31, 2026, ending a mission that lasted 378 days. Commander Ross Elder, medical officer Ellen Ellis, flight engineer James Spicer and science officer Matthew Montgomery had entered Mars Dune Alpha on October 19, 2025, for NASA's second Crew Health and Performance Exploration Analog mission, known as CHAPEA.

Mars Dune Alpha is a 1,700-square-foot, 3D-printed structure at NASA's Johnson Space Center. It has no windows, and the crew had no live calls with anyone outside. Messages traveled with delays of up to 22 minutes each way, matching the lag a crew on Mars would face, and the mission included a planned two-week communications blackout of the kind a solar conjunction would impose.

The crew was picked for the jobs a Mars surface team would need. Elder is a U.S. Air Force experimental test pilot. Ellis, the medical officer, is a U.S. Space Force officer. Spicer brought experience in satellite communications and spacecraft development, and Montgomery, the science officer, came from hardware engineering and robotics.

Inside, the four ran simulated Marswalks, operated robots, exercised, maintained the habitat's systems and grew crops. Montgomery ran a seed-germination experiment in simulated Martian soil and identified rock samples from the Marswalks. When the mission ended on Halloween, NASA astronaut Jack Hathaway knocked on the habitat door, called out “trick or treat,” and opened it.

NASA published the crew's reflections on November 9, and the four are now in post-mission evaluations, with two weeks of debriefs ahead. Principal investigator Grace Douglas and her team will work through the health and performance data alongside the results from CHAPEA's first mission, whose crew — Kelly Haston, Ross Brockwell, Nathan Jones and Anca Selariu — lived in the same habitat from June 25, 2023, to July 6, 2024, for the same 378 days. The habitat can't reproduce Martian gravity or radiation, and NASA doesn't claim it does. What it produces is the human record — sleep, food, workload, teamwork, delay — and the agency says that record feeds the design of both Mars surface missions and future lunar bases.