It’s a little crowded inside the airlock at Mars Dune Alpha, where seven of us are packed in a space ordinarily meant for two, poised on the threshold between shelter and the unknown.
Dr Suzanne Bell disengages the locking lever and swings the outer hatch wide open, revealing a landscape of rust-red dust and rocky cliffs beneath a brilliant white sky.
“Welcome to Mars,” she announces.
The atmosphere on Mars is less than 1 per cent of Earth’s surface pressure and comprises largely carbon dioxide, with only trace amounts of oxygen. Minus a spacesuit, helmet and life-support systems, I would suffer rapid collapse and — within a couple of minutes — death by suffocation if this were a true red-planet scenario.
Here in the Crew Health and Performance Exploration Analogue (Chapea), a simulated Martian habitat at Nasa’s Johnson Space Centre (JSC) in Houston, Texas, the stakes are lower and crew members face mock challenges without danger.
Throughout their 378-day missions — one completed last year and another two to come — almost everything else here mimics life on Mars as envisaged by scientists and engineers. The purpose is to help researchers understand and mitigate the physical and psychological challenges and inform the design of future missions.
“Mars is a hostile environment not inherently conducive to human life, so we need to learn how we can support crew to live and work there,” said Dr Bell, a psychologist at Nasa and Chapea’s co-investigator for behavioural health and performance research.
Last year’s Chapea crew leave their simulated Mars mission. The identities of this year’s participants have yet to be announced
NASA
“The crew we select are incredibly astronaut-like individuals. They aren’t just people who didn’t have anything to do with their lives for a year. When we land a crew on Mars someday, the Chapea crew will have had a contribution to what we send, to how we monitor human health and performance, to the success of the mission. It’s a critical project on the pathway to Mars.”
Nasa and its international partners are working towards returning humans to the surface of the Moon in 2027 under the Artemis programme as part of a “stepping stone” approach to one day sending crew to Mars.
The Moon is 250,000 miles away, a three-day journey from Earth. Mars, at its closest, is 33.9 million miles from Earth, and the trip will last seven to ten months each way, with a stay of up to 18 months in between.
Inside Nasa’s Mars simulator
Mars Dune Alpha, located inside a hangar at JSC, provides just 1,700 sq ft of living space — roughly the size of a small to average-sized home — plus the 1,200 sq ft “sandbox”, the mock surface environment that lies beyond the imitation airlock, encased by an inflatable dome.
A crew of four, whose identities have yet to be announced, is due to move in in October.
They must withstand challenges such as resource limitation, equipment failures, mock emergencies and the psychological stress of confinement and isolation, unable to step into — or even glimpse — the real world for 378 days.
The crew of Chapea Mission One last year spoke of missing nature — the green of the grass, the blue of the sky and the twinkling of oceans — and of longing to feel fresh air on their faces, hug family and friends and savour freedom.
For 378 days they lived as Martians. Now they are back
They carry out simulated spacewalks lasting up to six hours at a time, using virtual-reality headsets to enhance the visual landscape while hooked up to a special treadmill that replicates the ups and downs of the ground.
Treadmills simulate the terrain of Mars
DANIELLE VILLASANA
Tasks also include conducting robotic operations, including a drone and rover, undertaking daily chores such as habitat maintenance and cleaning — “because that red dust gets everywhere”, notes Chapea’s project manager, Daniel Hernandez — and exercise routines in the fitness room.
There is a crop-growth station in which to cultivate produce such as tomatoes, leafy greens, peppers and herbs, to supplement otherwise pre-packaged foods that are freeze-dried or thermostabilised — akin to supplies on the International Space Station (ISS).
The crew will grow and harvest crops to supplement their diets
NASA
Communication with family and colleagues mimics the 22-minute time delay in space
DANIELLE VILLASANA
Unlike the ISS, however, which orbits Earth at an altitude of 250 miles and can be reached within hours, Chapea adopts a strictly Martian logistics regime — meaning the entire food supply for the year is pre-positioned, with no deliveries of fresh fruit and vegetables to relieve menu fatigue and boost morale.
Chief among the challenges is the realistic time delay in communications.
“The important thing here is that we have a resource-restricted environment, so just like when a crew is on Mars some day, there’ll be up to a 22-minute communication delay each way for how they talk with mission control, how they talk with family and friends,” Bell explains.
“So I message you as my family member, you’re maybe out at a baseball game, you’re shopping, you respond later … so 44 minutes is the minimum. There’s also the time needed for the person to write the message — and if it’s a communication with mission control, they have to problem-solve anomalies on the ground before they can send that message back.
“Some of our tech demos have to do with artificial intelligence providing feedback to the crew, in order for them to troubleshoot different medical scenarios and understand better how a crew can autonomously respond in a positive way to emergencies while mission control is up to 22 minutes away. It may absolutely be too late by the time they ask for help and hear back.”
The habitat was constructed using a 3D printer and resembles layer upon layer of rust-brown toothpaste squeezed from a giant tube. It is made of lavacrete, a concrete-like substance, but mass-hauling construction materials to Mars would be impractical, prohibitively expensive and require hundreds of spacecraft. Instead, future Martians will rely on in-situ resource utilisation (ISRU), harnessing materials found in space, such as dust and rock to 3D-print habitats, tools and furniture, and water extracted from ice deposits to sustain life and manufacture fuel for the journey home.
Water is also recycled in Chapea — including the crew’s own urine, like the ISS. Each crew member gets a small, private room with a single bed, desk, chair and shelving. The common lounge area has a table for mealtimes, four individual chairs and a television screen on which they can play pre-recorded movies and programmes.
Remote teams of researchers monitor health and cognitive performance, blood samples are analysed, behaviour and psychology studied, calorie intake and burn rate measured, respiratory rates and water usage recorded.
There are rules against external noise; the sounds of a door slamming outside and chatter in the hallways are strictly barred to maintain the fidelity of the Martian environment.
Crew members are chosen using the same criteria as Nasa astronaut selection, including rigorous psychological examination.
“Teamwork is absolutely essential for Mars because there’s no abort capability; you can’t bring people back, you can’t swap out people. So at the end of the day there will be challenges, there will be things we didn’t expect and that crew has to get along and work together to solve it,” said Bell.
“We’ll prepare as best we can, we’ll send what we think needs to be sent … but at the end of the day you’re on your own on Mars and they’ll have to figure out whatever comes their way.”