A space travel reality check

When people talk about space tourism, the conversation often drifts to the spectacular, the thrill of rocket launches, breathtaking views of Earth from orbit, or the dream of floating effortlessly in zero gravity. But behind the glamour lies a question very few stop to ask: how will the average, untrained tourist actually cope with the physical and psychological rollercoaster of spaceflight?

A study published in PLOS ONE by a French-led team of researchers tackles this question head-on. Their work centers not on astronauts, who spend years conditioning their minds and bodies for space, but on everyday people stepping into a radically alien environment. And their laboratory wasn’t a faraway space station, but something closer to home: the Airbus A310 ZERO-G, a modified plane that offers brief, stomach-churning glimpses of weightlessness through parabolic flight. The findings? Space tourists will need more help than many imagine, not necessarily to survive the flights, but to recover from them.

The promise and peril of space tourism

For decades, only a handful of astronauts trained under the strictest conditions could access the microgravity of space. But with private companies like Blue Origin, Virgin Galactic, and SpaceX racing to commercialize space travel, the landscape is changing fast. For the first time, tourists with no scientific background, no astronaut boot camp, and no military conditioning may soon be floating among the stars, if they can afford a ticket that costs close to one million dollars per seat.

That raises an obvious issue: while astronauts spend 5–10 years training for their first mission, space tourists may get just a few months of preparation, if that. What happens when someone who has never been screened for cardiovascular health, balance issues, or stress resilience is suddenly exposed to violent shifts in gravity, confined spaces, and the emotional enormity of viewing Earth from above? This is exactly what the French team wanted to explore.

The researchers, including Barbara Le Roy from the French Armed Forces Biomedical Research Institute and colleagues from institutions including CNES (France’s space agency), the University of Lorraine, and the University of Bordeaux, recruited 17 healthy volunteers among scientists, doctors, engineers, and coordinators, to participate in the 79th ESA Parabolic Flight Campaign.

The Airbus A310 ZERO-G simulates space-like conditions by flying in steep arcs. Each arc produces about 20 seconds of weightlessness, sandwiched between stretches of crushing hypergravity (1.8 times Earth’s gravity). Over the course of a three-hour flight, the plane performs 30 of these parabolas, giving passengers repeated jolts of shifting gravitational forces.

The participants were carefully monitored before, during, and after their flights. The researchers didn’t just ask them how they felt, they measured heart rate variability, sleep quality, balance, stress levels, emotional state, and even sense of smell. Then, they followed up a week later to see how well everyone had recovered.

Who Handles Zero-G Better?

One of the clever aspects of the study was dividing participants into two groups based on something called parasympathetic functioning. The parasympathetic nervous system is often described as the “rest-and-digest” branch of our body’s stress response system. People with higher baseline parasympathetic activity (measured through heart rate variability) generally adapt better to stressful environments.

Sure enough, the study found that those with a high parasympathetic profile handled the flight better. They showed stronger coping abilities, greater awareness of internal bodily signals, and even preserved their ability to identify odors, yes, spaceflight can mess with your sense of smell. But while the high-parasympathetic group adapted more smoothly during the flight, they actually suffered more emotional letdown afterward. A week later, these participants showed dips in positive emotions and interoceptive awareness (their ability to sense what’s happening inside their body). In other words, they were great in the moment but struggled with the comedown. Meanwhile, the low parasympathetic group reported slightly better sleep quality after the flight, though both groups saw overall declines in rest.

Several findings challenge common assumptions. First, experience didn’t matter. Whether participants were first-time flyers or veterans with over 30 parabolic flights, their bodies and minds responded in essentially the same way. This suggests that short tourist flights may not get easier with practice, each flight is a fresh challenge. Second, postural stability was compromised across the board. Both groups struggled with balance after their flights, especially in conditions where visual cues were removed (like standing with eyes closed). Imagine wobbling uncontrollably after your space holiday, that could have serious safety implications. Third, recovery is the hidden hurdle. Most previous research assumed that people bounce back immediately after landing. This study shows the opposite: the real difficulties appear in the days following, when emotions dip, sleep suffers, and stress patterns shift. For space tourism, this means companies shouldn’t just worry about passengers in the air, but also about their well-being once they’re back on Earth.

The message is clear: the flights themselves may not be overtly dangerous for healthy people, but the aftermath needs serious attention. Tourists won’t just hop off a spaceplane and stroll back to work as if they took a scenic helicopter ride. They may experience subtle but meaningful disruptions to balance, sleep, and mood for days afterward. This has implications not only for the safety of passengers but also for liability, insurance, and customer experience. If a million-dollar trip leaves people exhausted, wobbly, and emotionally drained for a week, companies will need to rethink how they support their clients.

Astronauts have long described the “overview effect”, a sense of awe and even spiritual transformation when viewing Earth from space. Some return with profound shifts in worldview, while others struggle with a disorienting emotional crash. Now, as space travel moves from a heroic few to a paying many, those same psychological currents will play out in tourists who may not be ready for them. Standing in zero gravity, watching our blue planet shrink against the black void, is bound to stir emotions far more complex than a rollercoaster ride. Space travel is about the fragile, resilient, unpredictable human body and mind.

We are entering an era where space is no longer the exclusive domain of astronauts. Tourists, entrepreneurs, and adventurers will soon find themselves living out dreams that once belonged only to science fiction. But as this study shows, leaving Earth is about navigating the strange, delicate aftermath when gravity reclaims you. If space tourism is to make a leap and thrive, companies will need to take the human body as seriously as rocket engines.

If you want to learn more, read the original article titled "Effects of repeated gravity changes during parabolic flight: Evidence of the need to assist space tourists to outer space" on PLOS One at http://dx.doi.org/10.1371/journal.pone.0320588.