Four people are currently sealed inside a 3D-printed habitat at NASA’s Johnson Space Center in Houston, living on a Martian schedule – and they’ve been there since October 2025. They can’t just step outside when they feel like it. Every message home travels with a 22-minute delay each way. Their day runs 40 minutes longer than Earth’s, every single day, for a year.
That mission – NASA’s CHAPEA Mission 2, which began on October 19, 2025 – is still running. And now, before it’s even finished, NASA is recruiting the next group of NASA astronaut simulation volunteers to take things significantly further.
Beginning no earlier than August 2027, research volunteers will spend one year living and working in interplanetary environments at the agency’s Johnson Space Center in Houston, operating under isolated conditions expected during crewed missions to the Moon or the Red Planet. This time, though, the simulation won’t just replicate life on a planetary surface. It will replicate the entire journey – the months of transit through deep space, the surface operations, and the long return. No previous ground-based analog has attempted all of that in a single continuous mission.
The scale of what NASA is building toward explains why. According to a NASA technical overview, crewed Mars missions are estimated to be 700 to 1,200 days in length, two to three times longer than any continuous human spaceflight mission to date. Getting people to the Red Planet safely means solving problems that can’t wait until the rockets are ready. Many of the most dangerous problems are human ones.
What the Moon and Mars Exploration Analog Actually Is
The Moon and Mars Exploration Analog (MMEA) evolves elements of NASA’s HERA (Human Exploration Research Analog) and CHAPEA (Crew Health and Performance Exploration Analog) missions into a single, integrated mission to streamline how researchers evaluate astronaut adaptation. In plain terms: HERA has spent years studying the effects of isolation during spaceflight transit, while CHAPEA has focused on simulated life on the Martian surface. The MMEA merges both into one unbroken year-long experiment.
While NASA has performed 28 transit and two surface habitat simulations, the MMEA will be the first project to incorporate the two. The physical setup reflects that dual purpose. Using the HERA habitat as a simulated spacecraft and the CHAPEA habitat as a surface base, the volunteers will live and work in confined, isolated environments that simulate months-long flights to and from other planetary surfaces. The HERA habitat covers approximately 650 square feet – roughly the footprint of a small apartment – while the CHAPEA habitat, a 3D-printed structure known as Mars Dune Alpha, spans approximately 1,700 square feet.
Volunteers will also mimic surface operations, including mock Mars walks and using a rover to travel to exploration sites located beyond the main habitat. They’ll grow their own food, conduct scientific experiments, and carry out routine habitat maintenance. None of this is passive observation. The crew will carry out scheduled maintenance tasks, complete scientific experiments, respond to simulated emergencies, and settle into routines that could define life millions of miles from Earth.
Throughout the mission, researchers will study crew health and performance under resource limitations and mission demands. These missions also help NASA assess and validate hardware, technologies, protocols, requirements, and other systems designed to support crew health and performance on long-duration deep space missions – all without leaving Earth.
The Full Commitment: 14 Months, Not 12
Applicants who read “yearlong mission” and assume they’ll be done in twelve months will want to check the fine print. Volunteers must consent to an approximately 14-month commitment, including 12 months in two different confined habitats and two months of pre- and post-mission training and data collection.
The eligibility requirements are deliberately stringent. To qualify, applicants must be U.S. citizens or green card holders, between 30 and 55 years old, no more than 74 inches tall, and proficient in English. A bachelor’s degree from an accredited institution in engineering, biological science, physical science, or mathematics is required. Those with advanced STEM degrees can also apply, and military experience will be considered.
There are also practical health requirements that go beyond a standard physical exam. Applicants must have no dietary restrictions and no history of sleepwalking or taking sleeping aids. That last point isn’t arbitrary: volunteers will have to adapt to the Martian day/night cycle, which runs 40 minutes longer than an Earth day. Over a year, that cumulative drift compounds significantly, making sleep regulation one of the genuine physiological challenges the study aims to measure.
NASA is recruiting four participants for the mission. A NASA spokesperson told CNN that the research program would help reduce the risks astronauts may face when flying to space and landing on Mars.
What the Previous NASA Astronaut Simulation Volunteers Have Already Taught NASA
The MMEA doesn’t emerge from a vacuum. NASA’s CHAPEA program has been running Earth-based Mars simulations since 2023, producing real data on what prolonged confinement actually does to people.
CHAPEA Mission 1 began June 25, 2023, while Mission 2 began October 19, 2025. The first mission ran for 378 days with four crew members. The second is currently underway and scheduled to conclude October 31, 2026 – also 378 days. Mission 2 specifically aims to investigate how the crew adapts and responds to various environmental stressors including limited access to resources, prolonged isolation, 22-minute communication delays, and equipment failures.
Those communication delays deserve attention. On a real Mars mission, a message sent from the surface reaches Earth 22 minutes later – and any reply takes another 22 minutes to return. That 44-minute round-trip lag means no real-time troubleshooting, no spontaneous conversations with family, and no immediate medical consultation if something goes wrong. Currently, the CHAPEA 2 crew is in a simulated two-week loss-of-signal period that mimics a Mars-Earth communications blackout when Mars moves behind the Sun – during which the crew works without contact with mission control, using preplanned procedures and available resources to complete tasks and handle any issues that may arise.
Sara Whiting, project scientist and mission manager at Johnson for NASA’s Human Research Program, noted that “extended-duration missions are relatively rare in NASA’s history to date,” and that “the operational lessons learned, along with the detailed health and performance data this crew is providing, come at the perfect time to inform the development of a sustainable lunar presence and longer-term objectives for crewed Mars missions.”
The Human Body Under Confinement: What the Research Shows
The physical setup of these simulations is demanding. The psychological dimension is where the data becomes genuinely sobering.
According to NASA’s own Human Research Program, the prolonged isolation and confinement that astronauts face can increase risks of behavioral issues and psychiatric disorders, including anxiety and depression – factors that may impact sleep, morale, and decision-making, making ongoing research into psychological health essential for future mission safety.
A 2025 review published in ResearchGate that integrated findings from space analog missions and historical spaceflights found that prolonged confinement produces a range of psychological effects including neurocognitive shifts, sleep disruptions, mood changes such as anxiety, depression, and irritability, and interpersonal conflicts.
That interpersonal dimension is particularly relevant when four people are locked in a space no larger than a mid-sized house for a year. Crew dynamics under extreme stress are not just a comfort issue – they’re a mission-critical variable. Astronauts aboard the International Space Station can virtually talk with family and medical professionals for support, but extended communication delays on a multi-year trip to Mars will create new challenges that current ISS-based research simply cannot replicate.
Research on strategies that help volunteers manage these psychological demands points to some specific findings. A study published by the British Psychological Society found that more time spent talking with fellow crew members about personal matters, or engaging in leisure activities, was associated with reduced negative emotional effects during simulated space isolation. Structured downtime isn’t a luxury inside these habitats. It’s a research variable.
You can read more about how long-term stress affects the body at a physiological level in this look at how Artemis astronauts are trained and compensated for the demands of deep-space missions.
Why This Matters for the Artemis Timeline
The urgency behind the MMEA has a concrete deadline attached to it. Insights from the yearlong MMEA experience can be used to help keep astronauts safe and mission-ready during future planetary surface operations, and the results could also inform plans for a sustained lunar presence through NASA’s Moon Base and future Artemis missions.
“In previous missions, the habitat was intended to simulate a well-established, larger surface habitat, but MMEA missions are designed to simulate an earlier phase of Mars surface infrastructure, which is also applicable to helping NASA answer questions about near-term Moon Base objectives,” a NASA spokesperson told CNN.
NASA currently targets early 2028 for the first Artemis lunar landing, with subsequent missions planned roughly once per year. Getting humans back to the Moon on that schedule, and keeping them there long enough to matter scientifically, requires understanding how the human body and mind hold up under conditions that no short-duration mission can adequately stress-test.
Mars is the longer horizon. Space.com noted that NASA aims to launch astronauts to Mars by the late 2030s or early 2040s. The science underpinning that timeline is being built right now, inside a 3D-printed habitat in Houston, by four volunteers who won’t see the outside world until October.
What This Means for You
If you’re between 30 and 55, hold a qualifying STEM degree, are a U.S. citizen or green card holder, and have genuinely considered what it would mean to contribute to one of the most consequential scientific programs of the next decade, the MMEA application is worth looking at seriously. Full eligibility details are listed on NASA’s official recruitment page. The mission doesn’t begin until no earlier than August 2027, but selection and pre-mission training begin well before that.
For everyone else, what this program represents is more than a curiosity. The data coming out of CHAPEA and MMEA will directly shape how future astronauts eat, sleep, communicate, and manage stress on missions that will last longer than anything humans have attempted in space. The psychological and physiological findings from these ground-based missions feed directly into mission design, habitat layout, and crew selection protocols. The four people who volunteer for the MMEA starting in 2027 won’t be going to Mars. But the people who eventually do will owe a significant debt to whatever those volunteers are willing to endure inside two cramped habitats in Houston.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.
Read More: 5+ Things Artemis II Found On The Far Side Of The Moon