For most people, the thought of spending every waking hour with strangers in a metal capsule roughly the size of a studio apartment for weeks sounds like the stuff of nightmares.
For others, it’s a dream.
About 400 people applied this year to live, work, and sleep in NASA’s Human Exploration Research Analog, a three-story habitat built to mimic the confinement of space missions and study human behavior and teamwork dynamics. The space agency has spent the last several months shuffling groups of four volunteers in and out of the habitat, which sits inside a warehouse at the Johnson Space Center in Houston. The groups live in the habitat for 45-day stays designed to simulate a round-trip journey to an asteroid to collect and return soil samples. The latest group emerged this month, were greeted with sparkling fruit juice, and returned to their daily lives, with some much-needed privacy.
The participants are essentially lab rats, the test subjects that will inform the procedures and protocols necessary for future missions to Mars and deep space. Everything that happens to them in that metal tube—their physiological changes, mood swings, interpersonal interactions—will someday be folded into guidelines for keeping astronauts happy and healthy on long-term missions. Similar campaigns to study human behavior for space journeys are underway elsewhere, including a University of Hawaii program called HI-SEAS that put six people in a fake Mars habitat in Hawaii for eight months this year.
“I’ve built a career asking other people to be test subjects. I felt like I owed it to the science to be a guinea pig myself,” says Rick Addante, a psychology and neuroscience professor at California State University at San Bernardino. Addante and three others moved into the HERA habitat in August. “If we want to get to Mars, we have to use our brains, but we also have to understand our brains and what’s going to happen to them on the way to Mars,” he says.
For now, though, the goal of analogs like HERA and HI-SEAS is to get people to survive weeks of confinement in good health—without losing it or turning on each other. The HERA program is part space camp, part escape room, and pays $10 an hour. Crew members are all in it together—literally—so making it work is their only option.
“I had a lot of faith in the powers that be to select a good crew,” says Reinhold Povilaitis, a former HERA crew member and research analyst at Arizona State University who works on a NASA moon orbiter. “Before I went in, I reminded myself to keep an open mind about everything.”
NASA picks “astronaut-like” volunteers, people between ages 30 and 55 who have advanced degrees in science fields or some military experience and can pass medical, physical, and psychological screenings. Participants must also pass virtual-reality motion-sickness tests to prepare for simulations of space walks and sample collections using VR headsets. After that, assembling a crew is kind of like an admissions office pairing roommates in the first year of college. HERA staff tries to pick people who will get along. “They may or may not become best friends, but they work together,” says Lisa Spence, the flight-analog project manager for HERA.
The experience is meant to be as isolating as possible, far more extreme than the environment on the International Space Station. Unlike ISS astronauts, HERA crew members—or HERAnauts, as they’re called—had no internet access and get just 30 minutes a week to call family and friends. Their only connections to the outside world were the handful of NASA employees who monitor them and electronic copies of the Houston Chronicle and U.S.A. Today, delivered every weekday. Their workdays were scheduled to the minute, packed with sample collections, simulations, drills, and wellness tests and screenings.
“It’s weird not to see the sun and not hear the rain and not feel the wind,” says Tim Evans, a biology professor at Grand Valley State University in Michigan who stayed in the HERA habitat from May to June. “But you don’t dwell on that because you’re so busy doing other things.”
NASA closely monitored the crew’s health. They took surveys asking them about their emotional states and math tests that targeted their cognitive function. Their diets—consisting of freeze-dried or thermo-stabilized foods made for microgravity—were tightly controlled. No breath mints were allowed on board, since those would add an extra calorie or two to the daily intake. Participants wore sensors to track their vitals (and, during virtual-reality simulations, their brain activity) and regularly gave blood, urine, and fecal samples. For the blood draws, crew members stuck their arms through a hole in a curtain in the habitat’s airlock, where a “robot”—actually a HERA staffer—stuck a needle in their veins.
On top of that, crew members were deprived of sleep. To study how lack of adequate slumber affects humans, the HERA program kept participants awake for 19 hours every weekday. “We would stand around at 1:59 a.m. just waiting for the clock to go to 2 a.m. so we could go upstairs [to our bunks] and go to sleep,” says Shelley Cazares, a research scientist at the Institute for Defense Analyses in Virginia who stayed in the HERA habitat in August. On weekends, they were allowed a full eight hours of sleep a night.
But the deprivation was taxing. The books some crew members brought with them for entertainment instead put them to sleep. “I’d wake up tired and be tired all day,” Evans says.
The lack of sleep negatively affected their cognitive and motor skills—they made more mistakes when maneuvering a robotic arm on the habitat, for example—and sometimes made them irritable and grumpy. “We all joked about there being a kind of honeymoon phase, where we’d get up in the morning and say, ‘Hey, how are you doing, how’d you sleep?’” says John Kennard, a Green Beret in the U.S. Army who teaches cyberdefense at Fort Bragg in North Carolina. Kennard stayed in the HERA habitat from May to June. “And then after about a week, it was more like grunts than actual conversation. You figure out who’s less talkative in the morning, who needs their own space to fully wake up.” James Titus, Kennard’s fellow crew member, heartily agreed. “In the morning, in-depth conversation could not happen,” says Titus, who works for a nuclear-fusion start-up in California. He said he would dab some Tabasco sauce on his tongue when he started to feel himself dozing off.
The resulting crankiness naturally led to some misunderstandings among crew members. Tension, in general, is pretty unavoidable in such an environment. One crew member likened the experience to a long family car ride across the country, where people are bound to get on each other’s nerves at some point. The key difference is that they can’t leave the HERA habitat for a walk, and must instead talk it out.
Time slows down inside the habitat. A day could feel like an entire week, some crew members say. To pass the time when they weren’t working, the crew played board games and watched a ton of movies. One crew watched every installment of Star Wars, The Lord of the Rings, and Harry Potter.
Sometimes, when the Houston Chronicle delivered a big story, like the firing of FBI director James Comey in May, they’d talk about politics. Crew members often had different political leanings, but they say their discussions remained respectful and productive. “It was, in a lot of ways, the types of discussions you have when you’re in college and you would have that time to sit there and actually hash something out,” says Mark Settles, a plant-cell and molecular biology professor at the University of Florida, who was in the habitat when the Comey news broke.
The isolation had some perks, like the lack of email and all its anxiety-inducing qualities. “It was pretty freeing,” Settles says. Of course, when he returned to the real world, “it took me months to catch up on the things that I had missed,” he says.
The outside world crept into the habitat in a very big way in August, when Hurricane Harvey arrived in Houston, wreaking havoc on the city. A crew was about halfway through their mission at the time, and they tracked the storm’s developments through their daily newspaper deliveries. When Harvey moved to front-page news, NASA started calling the crew member’s emergency contacts, just in case. When tornado warnings were issued in the middle of the night, HERA’s mission-control staff roused the crew members and told them to huddle together on the first floor of the habitat. On the morning of August 27, as Houston’s roads and highways swelled with floodwaters, NASA decided to abort the mission. The rising water made it difficult and dangerous for HERA staff to come in, and the HERAnauts couldn’t be left alone.
The crew had about 20 minutes to pack up their stuff and grab their astronaut food. “We stepped outside and I asked the first person I saw, ‘Why did we cancel?’ And he said, ‘Well, just go outside and you’ll see,’” says Paul Haugen, one of the crew members and a NASA engineer. They stepped out of the habitat and found a whole city underwater. The crew piled into a van and drove carefully to a hotel across the street.
Spence, HERA’s project manager, doesn’t know yet whether NASA will use the data gathered during the shortened mission. The crew that got Harveyed, as Spence puts it, was, naturally, disappointed about such an abrupt end. The crews that completed the full 45 days had a slightly different outlook when they stepped out of the habitat. The members had become friends, and would stay in touch after they left the habitat—texting about inside jokes and even how grouchy they could get—but when that airlock popped open, revealing the world they had pretended to leave, they were thrilled. Their work was done. The astronauts of the future will benefit from what NASA learns from this experiment—but they’ll need to wait far longer to feel the relief of coming home.