As well as performing experiments while in space, astronauts are also subjected to many, many tests themselves, before, during and after they’ve been in orbit. Returnees become a veritable human research hub after touchdown, with experts looking at the effects of space travel on their bodies. While studying one particular astronaut, though, NASA scientists made an alarming discovery.
Clearly, the human body wasn’t originally built for the environment in space. Without gravity’s constant influence, astronauts can suffer some rather odd and dangerous side-effects. As such, NASA scientists perform myriad tests on those who are about to, or already have spent time off-planet. That research includes recording vital signs, taking saliva swabs and blood tests, and conducting ultrasound scans.
And those procedures aren’t performed once, but multiple times – pre-launch, post-landing, and even during the mission. In fact, the astronauts test themselves while in orbit, with the results transmitted back to NASA headquarters. All of this data forms part of the space agency’s Human Research Program (HRP), dedicated to finding and fixing the ill-effects of being off-planet.
From coping with weightlessness in a zero-gravity environment to the unpredictable behavior of microbes in space, anything and everything about space travel is studied in great detail. The astronauts themselves are constantly monitored to ensure their continued health, and in the rare case of a medical problem they’re all trained in CPR. But there’s another aim behind the data-gathering.
Collectively, all the test results will eventually help astronauts cope with the long-term effects of space travel. NASA has planned a manned trip to Mars for a long time, but the journey would take at least three years. We’ve no idea how the human body would react to being weightless for that long. The HRP data is building up a detailed picture of the potential pitfalls.
Over the course of NASA’s 62-year history to date, it’s learned a lot about space travel. Having sent nearly 600 people into orbit, some lucky astronauts to the moon and many to the International Space Station (ISS), the agency knows that everyday life off-planet is almost nothing like living on Earth. This presents a huge challenge for everyone involved.
Living in zero gravity can affect many bodily processes, from sleep patterns to appetite. Added to that, every astronaut on a mission to the ISS is responsible for research, maintaining their own health and fitness as well as repair and maintenance of the station itself. Taking care of the ISS can include basic repair work and even spacewalks for larger jobs, all of which they do while weightless.
In September 2019 former astronaut Dr. James Pawelczyk described his experiences in zero gravity to Britain’s Daily Express newspaper. He said, “If you can imagine yourself falling, but not feeling any wind, that is exactly the sensation you have of being in space.” And having traveled around the Earth a whopping 256 times, he clearly knows what he’s talking about.
Pawelczyk went on, “If you close your eyes [in orbit], you are immediately reaching out for something to grab. You are almost overwhelmed by the falling sensation, but you come to adapt to it over time.” The former astronaut also explained the real-world situation behind that feeling of plummeting through space.
Continuing, Pawelczyk said, “When we are in orbit, what we are doing is literally falling around the Earth. It is just the Earth’s surface rotates out of the way before we hit it.” But for some astronauts, that very practical view of space travel gives way to something more poetic.
Veteran space traveller Marsha Ivins, who spent 55 days in orbit, is one such astronaut. Talking to Wired magazine in 2014, she explained her own reaction to being off-planet. “You look down at Earth and realize you’re not on it. It’s breathtaking. It’s surreal. It’s a ‘We’re not in Kansas any more, Toto,’ kind of feeling.”
Ivins went on, “Space travel […] isn’t glamorous. But you can’t beat the view!” Being in orbit some 200 miles above the Earth and travelling at about 18,000mph, though, isn’t all cool floating water droplets and multiple sunrises. As the astronaut told the magazine, “It can be crowded, noisy and occasionally uncomfortable.”
The former astronaut went on to describe her working experience in orbit. “[We] were always busy – experiments, daily maintenance […] robotic operations. It was incredibly hard work, stressful in its own way and scary.” And that fear is more than understandable, given the alien environment in which space travelers exist.
Even simple things like sleeping, eating and using the toilet present their own, very specific, challenges on the ISS. Astronauts have to tie themselves down to rest, or they’ll float into the station’s equipment. Ivins explained the process to Wired magazine. “You strap your sleeping bag to the wall or the ceiling or the floor, wherever you want and get in. It’s like camping.”
After strapping down legs and head, Irvin said, “If you don’t tuck your arms into the bag, they drift out in front of you.” And mealtimes aren’t much easier. There are few kitchen appliances in space, so meals are mostly freeze-dried in advance and transported to the ISS. Snacks are then warmed up in a small oven. And it seems that years of research have confirmed peanut butter as the perfect space food. Why? No crumbs.
Of course, at some point during an astronaut’s day, they’ll have to use the bathroom. This, too, changes in a zero-gravity environment. While hovering above the loo, ISS residents also have to strap themselves down to keep from floating away. And you don’t want to know what happens when they flush… Clearly, then, the peculiarities of space travel can be tricky. But they’re nothing compared to the possible physical issues space travelers face.
A zero-gravity environment has an effect on anything that existed on Earth before journeying into orbit. Naturally, this means for humans that there will inevitably be physical consequences of leaving the safety of the planet. However, there are emotional side-effects to space travel as well. Missions can last from days to months, and in one case, an entire year. And that can take a serious toll on ISS residents.
For instance, the physical and emotional distance from family can present problems for astronauts. Add this to essentially being trapped in a gigantic floating can, and mental health issues while on board the ISS can be a problem. Regardless of training, according to NASA, “The more confined and isolated humans are, the more likely they are to develop behavioral and cognitive conditions and psychiatric disorders.”
Having studied the effects of space travel on the human body for over ten years, NASA knows that astronauts are very likely to experience several physical effects while weightless. For one, in zero gravity, fluid from the lower half of your body floats toward your head. According to Ivins, “It’s a great facelift,” but your face does swell. And that migration of blood also causes other issues.
That huge amount of blood moving to your head can lead to headaches, dizziness and nausea. It can also cause swollen optic nerves and visual problems. It can also cause swollen optic nerves and visual problems. And then there’s diminished bone density, a decrease in muscle strength and a reduction in heart health to contend with, as floating around requires very little effort. Weightlessness can also result in kidney stones, as calcium depletion is another side-effect of reduced gravity.
Space travel also increases an astronaut’s risk of cancer, not just while on the ISS, but over the course of their lifetime, thanks to the increased radiation exposure in space. And while this list of dangers is scary, it’s by no means definitive. In fact, NASA recently added yet another risk factor after a terrifying discovery in the blood of an ISS resident.
In 2019 NASA researchers were looking into the effects of zero gravity on vision. Conditions involving the eye while on board the ISS can include flattened eyeballs and swollen optic nerves. So prevalent are sight problems that the space agency began leaving glasses on the station for those affected by the issue.
NASA scientists wanted to test the theory that vision problems due to zero gravity had a specific starting point. And that’s the migration of fluid from the legs to the head. As we mentioned earlier, that movement of blood causes myriad small problems, including altered sight as a result of inflamed optic nerves.
As part of NASA’s research, scientists homed in on the jugular vein as the possible origin point for sight issues in zero gravity. This vessel moves blood from the head back to the heart while you’re upright, but closes when you’re lying down. Researchers then recruited a total of 11 anonymous astronauts to take part in a study looking specifically at blood flow through that vein.
Researchers measured the rate of blood flow in the jugulars of the 11 astronauts before they left for the ISS. All had normal readings. While on board, the study participants had to perform their own tests, using an ultrasound. Guided by experts back on Earth, each space traveler relayed their results back to Earth. And what they found shocked NASA’s scientists, especially as it had nothing to do with vision.
The results showed some very disturbing changes in the blood of several of the astronauts. One of them was even facing a life-threatening condition. The rest of the team, however, didn’t fare much better. In the least disturbing of the results, five of the 11 study participants showed little to no forward movement of blood in their jugular veins.
That’s right, in five of the astronauts taking part in the study, their blood actually stopped moving. Which, as you can imagine, is pretty rare on Earth. NASA researcher Karina Marshall-Goebel, who worked on the study, explained the results to The Atlantic magazine in 2019. She said, “Sometimes it was sloshing back and forth a bit, but there was no net forward movement.” And the troubling results didn’t end there.
In a shocking turn of events, two of the astronauts actually showed a reversal of blood flow. Yup, it went in the opposite direction through their jugulars. According to Marshall-Goebel, that situation is, unsurprisingly, “extremely abnormal.” The scientists believe that redirection may have been caused by a blockage somewhere lower down the vein.
That backward-flowing blood, it seems, does happen on Earth, usually in patients with a mass or tumor in their circulatory systems. The resulting blockage forces the liquid to find another path around the body. And it’s this ability to reroute that scientists believe was causing the reversal of direction in the astronauts’ bodies.
For one astronaut, though, the weird blood behavior had a single, very serious side-effect. Their ultrasound also revealed a blood clot that required immediate treatment. As Marshall-Goebel told The Atlantic, “We were not expecting this. This has never been reported before.” Having started the study looking at vision, the team had accidentally discovered a whole new set of zero-gravity dangers.
The astronaut was immediately pulled from the study and given clot-busting drugs. Despite these alarming findings, upon return, it seems that all the study participants’ blood went back to normal behavior. Marshall-Goebel confirmed their health in her interview. She said, “None of the crew members actually had any negative clinical outcomes.”
But, as Marshall-Goebel, explained, “I think it was probably scary for everybody.” For the scientist, however, there was an upside to the alarming blood discovery. “I think the fact that we found this now is really, really good news. […] If you know this is a risk factor of space travel, it’s something you can monitor and prevent.”
Obviously, acquiring blood clots while traveling in space is far from ideal. But it may have been happening all along, while astronauts remained blissfully unaware of the danger. And for Marshall-Goebel, the lack of lasting effects just proved the impressive adaptability of the human body; she said, “It’s almost like a detour, when you’re in your car and you sometimes have to go down the wrong street to get where you need to go.”
However, with NASA planning a manned trip to Mars in the near future, the blood clot discovery highlights how surprising the effects of being off-planet can be. As space medicine associate professor Virginia Wotring told The Atlantic, “We definitely have enough evidence to consider this to be an important risk to human health in spaceflight that warrants additional research.”
With regard to long-term missions, including that trip to Mars, Wotring said, “I think we need to understand [the blood flow issues] before we embark on long-duration missions where the astronaut would be so far away that we wouldn’t be able to help them in the case of a medical emergency.” But the concern isn’t just for ISS crew members and the like.
Indeed, if companies such as Elon Musk’s Space X turn space travel into a commercial vacation enterprise, how will ordinary citizens cope with the increased risks and inevitable effects of weightlessness? Cornell University geneticist Christopher Mason shared his concerns with The Atlantic, asking, “We take these super-fit astronauts up and they can adapt and be okay, but what will it look like when we send two random people?”
Mason went on, “Hopefully [those people will] be fine, but we don’t have really any data on it, so it’s hard to tell.” As a result of the blood clot discovery, NASA is planning to implement a blood-monitoring program for all ISS crew members. In addition, it will be installing the aforementioned scanning equipment on the station itself.
According to NASA, “[The ISS] is equipped with appropriate treatments in the medical kit available to crew members.” The space agency’s official site also explains that while there are generally no doctors on board, astronauts are trained in basic first aid. And in a real emergency, there’s always a trip back to Earth. However, on a journey to Mars, that simply won’t be an option.
On board a shuttle to the red planet, astronauts would be afloat in space, out of reach, for three years before arriving on Mars. For Wotring, then, the blood clot discovery has enormous implications. As she told The Atlantic, “There are an awful lot of effects of space on the human body that we’re not aware of yet.”
Despite these known dangers, along with the risks we’ve yet to encounter, many astronauts would travel back to the ISS tomorrow. As Ivins put it to Wired magazine, “It was hard, it was exciting, it was scary, it was indescribable. And yes, I’d go back in a heartbeat.” Clearly, that mission to Mars will have no shortage of volunteers.