NASA’s second Mars simulation crew steps out after 378 days in a Houston habitat

Four people who spent more than a year pretending to live on Mars walked out of a sealed habitat in Houston on Saturday, 31 October 2026, and stepped outside for the first time in 378 days. They had not left the building since 19 October 2025. They had not spoken to their families in real time, eaten a meal they had not grown or rationed themselves, or felt rain, wind or open sky for over a year. And yet none of them had ever left Texas.

The four volunteers were the crew of CHAPEA Mission 2, NASA’s second year-long test of what a long stay on Mars would do to the human body and mind. CHAPEA stands for Crew Health and Performance Exploration Analog. An “analog” is a place on Earth made to feel like somewhere in space, so researchers can study the problems of a space mission without actually going there. The crew lived inside Mars Dune Alpha, a 1,700-square-foot habitat built with a 3D printer at NASA’s Johnson Space Center in Houston, and lived by Mars rules for the whole year: limited supplies, delayed messages and simulated spacewalks.

Their exit, broadcast live by NASA from 3 p.m. Eastern time, marked the end of the mission. But the science is only just beginning. The crew now faces two weeks of medical checks and debriefings, and NASA’s researchers will spend months working through the health and performance data the four volunteers produced — data that will feed into NASA’s Artemis programme, plans for a future Moon Base, and eventually the design of a real human mission to Mars.

At a glance

What happened: Four volunteers — Ross Elder, Ellen Ellis, Matthew Montgomery and James Spicer — exited NASA’s Mars Dune Alpha habitat in Houston on Saturday, 31 October 2026, ending the 378-day CHAPEA Mission 2 simulation that began on 19 October 2025.

Why it matters: A real Mars mission would keep a crew away from Earth for years. CHAPEA is NASA’s way of learning, safely on Earth, how isolation, rationed supplies and delayed communication affect health, mood and teamwork over a full year.

What happens next: The crew undergoes two weeks of post-mission medical evaluations and debriefings. NASA will analyse the data to improve food systems, medical care and psychological support for future Moon and Mars missions, and is already accepting applications for a broader Moon and Mars Exploration Analog due to start no earlier than August 2027.

What happened on 31 October

NASA had announced the exit in a media advisory on 28 October 2026, inviting journalists to watch the crew leave the habitat live. The ceremony began at 3 p.m. Eastern Daylight Time on Saturday, 31 October, and was streamed on NASA Johnson’s YouTube channel and social media accounts. Johnson Space Center Director Vanessa Wyche and NASA astronaut Jack Hathaway gave remarks, and the four crew members spoke as well.

The moment itself was simple but striking. The crew had to pass through an airlock to leave the building, just as astronauts leaving a real Mars habitat would. Media watching in person were gathered on a screen outside the hangar that holds the CHAPEA facility, and were able to see the crew step outside for the first time in more than a year. For the crew, it was also the first time they could speak to their families without a Mars-style time delay on every message.

The exit had been planned down to the day. The crew entered the habitat on Sunday, 19 October 2025, and the mission was designed to last 378 days — the same length as the first CHAPEA mission, so researchers can compare the two crews directly. Patterns that appear in both crews are far easier to trust than patterns seen in only one.

A year inside Mars Dune Alpha

Mars Dune Alpha is not a spacecraft, and it was never meant to be one. It is a 1,700-square-foot building — roughly the size of a small three-bedroom flat — built using 3D-printing technology on the grounds of the Johnson Space Center. Inside, it is divided into living quarters, work areas, a kitchen and a space for growing food. Outside the habitat, within the hangar, there is a simulated Martian surface where the crew carried out spacewalks in protective suits.

Life inside followed the rhythm of a real Mars mission. The crew conducted simulated spacewalks, exercised, performed habitat maintenance, grew plants in a hydroponic system, and managed their supplies carefully. Hydroponics grows plants in water with added nutrients instead of soil, which matters for space because soil is heavy and hard to transport. NASA released a photograph from inside the habitat in June 2026 showing vegetables growing in the crew’s hydroponic crop system — a small green reminder of how much of a Mars crew’s food would have to be grown on site rather than shipped from Earth.

The crew also lived with the constraints a real Mars crew would face. Their supplies were limited and their contact with the outside world was restricted. Even emails to their families travelled with a Mars-like delay, because radio signals take many minutes to cross the distance between Earth and Mars, and a real crew could never have a normal phone call home.

The four crew members each had a defined role, mirroring a real mission crew. Ross Elder was the mission commander. Ellen Ellis was the medical officer. Matthew Montgomery was the science officer. James Spicer was the flight engineer. That structure mattered, because one of the things NASA is studying is how a small team organises itself, solves problems and keeps working together when there is no one else to call for help.

Why NASA runs these missions

A journey to Mars would be the longest and most isolated trip humans have ever attempted. A crew would spend months getting there, many months living and working on the surface, and months coming home. For much of that time, they would be too far from Earth for a quick rescue, too far for a real-time conversation, and entirely dependent on the supplies and equipment they brought with them — or grew, built or repaired themselves.

That is a very different problem from the space missions of the past. Astronauts on the International Space Station orbit only a few hundred kilometres above Earth. They can talk to mission control instantly, receive fresh supplies within days, and come home in hours if something goes wrong. A Mars crew would have none of those safety nets.

CHAPEA is designed to do exactly that. The programme studies how isolation, stress, tight routines and limited supplies affect a crew over time, and how those pressures show up in their health, their mood and their performance. The data can help NASA work out how much food a crew really needs, how exercise equipment should be designed, how crew time is actually used compared with the plan, and what kind of medical and psychological support a crew will need when the nearest doctor is millions of kilometres away.

The programme’s principal investigator, Grace Douglas, said NASA was proud of the crew’s commitment and achievements on a fast-paced and highly demanding mission. Michael Stenger, chief scientist for NASA’s Human Research Program, said the mission had been valuable in beginning to teach the agency what year-long missions require, including medical and psychological care across communication delays.

What the crew went through

The mission was deliberately hard. NASA has said the crew faced the kinds of stressors that future deep-space crews will likely experience: communication delays, resource limitations and isolation. They dealt with equipment failures and the need to repair and maintain their own habitat, and with the slow grind of a routine that barely changed for more than a year.

The psychological pressure may have been the hardest part. Four people, in a small space, with the same faces, the same walls and the same schedule, day after day, for 378 days. There was no weekend away, no evening out, no chance to step outside for fresh air. Every disagreement had to be resolved inside the group, because there was nowhere else to go.

The physical demands were real as well. The crew exercised daily, because the human body weakens without gravity and without regular exercise — a problem that matters even more on a Mars mission, where the crew would need to stay strong enough to work on the surface after months in space. They also had to manage their food carefully, growing what they could and making their supplies last. NASA says the data could help it design better food systems for future lunar missions and use crew time more efficiently.

It is important to be clear about what CHAPEA cannot do. The habitat sits in Houston, under Earth’s gravity, breathing Earth’s air, protected by Earth’s magnetic field from the radiation that would bombard a real Mars crew. It cannot reproduce the low gravity of Mars, the radiation of deep space, or the danger of the journey itself. What it can reproduce is the human experience: the confinement, the isolation, the delayed messages, the rationed supplies and the slow test of living and working with the same three people for over a year. That is the part NASA is most worried about, because spacecraft can be engineered, but people cannot be redesigned.

The first crew, and why a second one matters

CHAPEA Mission 2 was the second of three planned year-long simulations. The first crew — Kelly Haston, Anca Selariu, Ross Brockwell and Nathan Jones — entered Mars Dune Alpha on 25 June 2023 and came out on 6 July 2024, also after 378 days.

A second mission matters because four people is a very small sample. Any finding from the first mission — how quickly morale dipped, how the food system held up, how the crew spent its time — could have come down to those four personalities, or to something specific about that year. Running a second crew through the same habitat, for the same length of time, gives researchers a basis for comparison. If the second crew struggled with the same things at the same point in the mission, that is a much stronger signal than anything seen once.

What happens next

The crew’s first job after leaving the habitat was to reconnect with their families, with whom they had communicated only through delayed email for over a year. Then the medical work began. The crew will undergo two weeks of post-mission evaluations and debriefings with NASA scientists, including health checks that will measure how their bodies have changed after a year in confinement and how they recover once they are out.

NASA’s science teams will then work through the health and performance data collected during the mission. That analysis will take far longer than two weeks. The findings are expected to inform the design of food and exercise systems, medical care and psychological support for extended missions, and to help NASA build decision-making support systems for crews that cannot ask Earth for immediate advice. The data will feed into preparations for the Artemis programme and planning for a future Moon Base.

Frequently asked questions

What is CHAPEA?

CHAPEA stands for Crew Health and Performance Exploration Analog. It is NASA’s programme of year-long simulated Mars missions, run inside a 3D-printed habitat called Mars Dune Alpha at the Johnson Space Center in Houston, Texas.

Who were the four crew members of CHAPEA Mission 2?

The crew was Ross Elder, the mission commander; Ellen Ellis, the medical officer; Matthew Montgomery, the science officer; and James Spicer, the flight engineer. They entered the habitat on 19 October 2025 and exited on 31 October 2026.

How long did CHAPEA Mission 2 last?

The mission lasted 378 days, from 19 October 2025 to 31 October 2026. That is the same length as the first CHAPEA mission, which ran from 25 June 2023 to 6 July 2024, so that researchers can compare the two crews directly.

Did the crew really have no contact with the outside world?

They were not completely cut off, but their contact was heavily restricted and delayed. They communicated with their families by email, with a Mars-like time delay on every message. They could not make normal phone calls or step outside the habitat for the entire 378 days.

What did the crew do all day?

They followed the routine of a Mars mission: simulated spacewalks on a mock Martian surface, habitat maintenance, exercise, scientific work, and growing crops in a hydroponic system. They also managed their limited supplies and lived under the communication delays and isolation a real Mars crew would face.

What will NASA do with the results?

The crew will undergo two weeks of medical evaluations and debriefings. NASA’s researchers will then analyse the health and performance data to improve food systems, exercise equipment, medical care and psychological support for future Moon and Mars missions.

Will there be a CHAPEA Mission 3?

CHAPEA was planned as three year-long simulations, and NASA is already accepting applications for a broader Moon and Mars Exploration Analog campaign that combines CHAPEA with its other simulation experiences. That mission is scheduled to begin no earlier than August 2027.

Has anyone actually been to Mars?

No. No human has travelled to Mars. Robotic rovers and landers have explored the surface, but CHAPEA is a simulation on Earth. Its purpose is to prepare for a future human mission, not to replace one.

Conclusion

The exit of the CHAPEA Mission 2 crew on 31 October 2026 was a quiet milestone in the long effort to send people to Mars. Four volunteers spent 378 days living by Mars rules inside a 3D-printed habitat in Houston, and walked out with a year of data that no laboratory experiment could have produced. The habitat could not reproduce the gravity, radiation or danger of a real Mars mission, but it reproduced the human test — the confinement, the isolation, the rationed supplies and the slow work of keeping a small team healthy and cooperative for over a year.

What happens now matters more than the ceremony. Two weeks of medical checks and debriefings will begin turning a year of lived experience into knowledge that future crews can use. The crew gave up a year of ordinary life to answer a simple question: can people live like this, for this long, this far from help? The answer will help decide when — and how safely — humans finally set out for Mars.

This article is for general information and education only. It is not legal or financial advice.

Sources

• https://www.nasa.gov/news-release/nasa-invites-media-to-crew-completion-of-yearlong-mars-simulation/ (NASA, 28 October 2026)
• https://www.engadget.com/2303277/nasa-second-year-long-mars-simulation-mission-ends-today/ (Engadget, 31 October 2026)
• https://en.softonic.com/articles/nasa-wraps-chapea-2-mars-simulation-378-day-mission-ends (Softonic, 31 October 2026)
• https://starpath.global/news/nasas-simulated-mars-crew-hits-one-year-in-houston-habitat-exit-set-for-oct-31/ (Starpath Global, 20 October 2026)
• https://cosmicherald.com/article/nasa-chapea-mission-2-crew-exits-mars-dune-alpha-october-2026 (Cosmic Herald, 28 October 2026)