Ever look at the stars and dream of traveling to one? Humans are already living in space – in the International Space Station 254 miles above Earth – and space agencies are busy plotting a future visit to Mars.
It’s no longer science fiction to imagine humans living permanently in deep space, but would you be ready for it? Test your knowledge of space with CNN’s Your Body in Space quiz.
You’ve been “spaced,” meaning you’ve been shoved out of an air lock without a space suit, in what might be deep space’s version of walking the plank. You will:
Nope, not A. Contrary to many older sci-fi flicks, like “Outland” and “Total Recall” (1990), your head and body will not explode. Your body remains intact – it’s what is going on inside that kills you.
Dropped into the sudden decompression of space, “all of the oxygen that’s in your body and in your lungs starts getting pulled out of your body into the vacuum,” said Dr. Kris Lehnhardt, a leading scientist in the Human Research Program at the NASA Johnson Space Center.
“Your lungs will start to expand in a way that will likely cause them to collapse or to pop,” he added, unless all the air in your lungs is immediately expelled.
It’s not C either. Space is an unthinkable minus 455 degrees Fahrenheit, very close to absolute zero, the point when no heat energy remains. But the only way that heat transfers in space is via radiation, a very slow process. It would take hours for all the heat to radiate from your body and turn you into a popsicle, and you’d be dead from oxygen deprivation long before that happened.
What about D? Could you live long enough to cross a gap of space between two spacecraft? Expanse fans know Naomi did push all the air out of her lungs just as the space lock opened, which theoretically means her lungs would not explode. She also used an injection of some oxygen mixture just as she was about to pass out.
“That might be possible, but nothing like that oxygen injection exists today, so that scene is more on the fiction side of science fiction,” Lehnhardt said, adding that even if she made it, she would need immediate access to a hyperbaric chamber and medical treatment to survive.
The answer is B. The “woosh” of air escaping from the airlock will propel you out into space – and your dead (and ultimately frozen) body will travel at that momentum until it hits a piece of space junk or is burned to a crisp by a star.
You’re living in space in the future, having grown up traveling between the stars. You’re out for a deep space stroll, when suddenly your nose itches – and doesn’t stop. You decide to:
The answer is A. “Today, you’d have to suffer in itchy agony, I’m afraid,” Lehnhardt said.
If you choose C, you could be right someday, in a galaxy far, far away.
“If humans were truly evolved for the space environment, would it be possible for someone to do something like that for a brief instance? It’s certainly conceivable,” Lehnhardt said.
“You would basically breathe out all the air of your lungs, hold that, scratch your face, and then put your mask back down and take a breath,” he said. “It’s possible that could happen in the future with people who live in deep space for long periods of time, but it would not be possible today.”
You were born in space, with no access to planetary gravity. Now your grandparents are sick, and your parents, who were born on Earth, want to travel home to visit. You will:
The answer is C. “If you were born in microgravity. I don’t think you would ever have the ability to walk around on Earth,” Lehnhardt said. “How would a baby’s muscles and bones develop in a way that would ever allow them to stand and walk on purpose?
“The moment astronauts get into space, their bodies begin to adapt to the space environment. The systems in their body that are gravity dependent start to be less important. Your inner ear, for instance, has to change the way it works for balance, and your muscles and bones have to change when there’s a lack of gravity as well,” Lehnhardt said.
In today’s space missions, bone loss begins within days and is at its worst between the second and fifth months in space, NASA says. Astronauts have returned to Earth with up to 20% bone loss. Why? No one knows, but it’s possible that microgravity may cause bone to break down faster.
Astronauts maintain an intense nutrition and exercise program and take medications to build bone while in space, but they still do not recover all of the lost bone mass when they return, Lehnhardt said.
“We may never get to a point where we can keep bone mass at 100%,” he said. “That might just be the nature of spaceflight and microgravity, but we are now able to preserve bone much better than we used to, which will hopefully serve our astronauts well in the long term.”
Now humans have lived in space for a century. How might our bones differ from what we have today?
Any answer might be right, but the likely answer is C. The only way mankind could keep our current skeleton is if we created “some kind of simulated gravity, or if we had special exercise and nutrition programs for them to build up those muscles and bones, and if their inner ears will allow them to respond and adapt to a different gravity environment,” Lehnhardt said.
“Your body is trying to be as efficient as possible. If your body essentially senses that you don’t need strong bones anymore because you’re floating around everywhere, then rightfully so, the body starts to adapt in a way that breaks down those bones because maintaining them requires energy,” he added.
It’s possible that humans in space will evolve to have no bones at all. Science fiction likes to speculate: In the sci-fi series “The Expanse,” for example, people born in space have elongated bone structures, bone abnormalities and weak muscles – and that’s just after a few generations.
You’re planning a vacation in to Voyager Station, the world’s first space hotel due to open in 2027. The station will spin to provide gravity, and builders say that they allow visitors to have showers, beds and toilets just as on Earth. But what would happen if the station malfunctioned and you lost gravity, say while you were urinating - or something else?
If you picked D, you’re right. “Two things would happen,” said Lehnhardt. “One, as you peed you would probably start moving backwards, because for every action there’s an equal and opposite reaction in space.
“The other thing that would happen is that the fluid itself would start coming together into bubbles because of the surface tension of fluid and the lack of gravity. It would be a very messy proposition.”
How do US astronauts pee in space? During the Space Shuttle missions, they used a cone connected to a tube of pressurized air that sucked the urine into the waste station. The International Space Station still uses a hose, but it’s designed differently.
It didn’t take long for the toilet to become a form of entertainment on the shuttles. Former NASA astronaut Mike Massimino recalls being challenged by another astronaut to pee upside down.
“And you can–you just flip yourself upside down,” he said in a video entitled “How hygiene is different in space.” “You need to be a little more careful,” he added quickly. “You don’t want to try that on day one.”
What if you were doing #2? Well, NASA has come a long way from the early Apollo days of taping baggies to astronauts’ butts. The Space Station has a toilet that astronauts must train on to be sure they are properly “aligned” with the hole. Afterwards, they are trained to use a mirror behind them “so as we got off the toilet, we saw if anything was following us, if you get what I mean,” Massimino said.
Still, there can be accidents. During the 1969 Apollo 10 mission astronaut Tom Stafford suddenly blurted out: “Get me a napkin quick. There’s a turd floating through the air,” according to a NASA transcript.
Astronaut John Young quickly replied: “I didn’t do it. It ain’t one of mine.”
Speaking of something else, is it possible to have sex in space?
NASA says the answer is C – no one knows. “To the best of our knowledge, no one has ever had intercourse in space,” Lehnhardt said. “We can’t say with certainty, but theoretically I don’t know why it wouldn’t be possible. It would be technically challenging, but I’m certain that if people want to, they can figure out how to do it.”
A huge concern about sex in space: What might happen to a baby conceived in the midst of the ever-present galactic cosmic ray (GCR) spectrum? Scientists are going to have to do a much better job of protecting humans from that radiation to avoid potential DNA damage and more. NASA is working hard on how to better protect humans in space, Lehnhardt said.
“Radiation can cause any number of degenerative conditions like dementia or heart disease or cancer,” Lehnhardt said. “Those are all potential risks in a mission to Mars. NASA believes that those risks are not high enough that they will stop us from going to Mars, but they are high enough that we are working on technologies and countermeasures to try and reduce the effect of the radiation or the impact of the radiation on the astronauts.”
In your first few days in zero gravity, your body will change. Which of these do you think would happen?
The answer is E – all of the above. Ever heard of “puffy head, bird legs” syndrome? That’s what happens to astronauts in zero G – legs become skinny and faces swell as the body’s fluids shift from the lower to the upper body. That doesn’t happen on Earth, of course, because gravity keeps blood in our lower extremities.
The unaccustomed extra fluid fills the sinuses, causing congestion – and because taste is connected to smell – reduces the ability to smell and taste, which affects appetite. In addition, space motion sickness, which can last for 24 to 48 hours, causes extreme dizziness and vomiting, which can also affect appetite.
“I felt like I was falling,” NASA astronaut Mike Hopkins told CNN in 2016. “It was as if you’re hanging off the rafters in a building, and you let go. My brain was taking a little while to get used to the fact that there was no up and down anymore.”
NASA still isn’t sure what causes the syndrome, which affects about 79% of astronauts.
“We’ve frankly have never been able to exactly pinpoint the cause of what used to be called space motion sickness and that now called Space Adaptation Syndrome, but it is believed to be a miscommunication between your vision and your balance and coordination system,” Lehnhardt said.
You got a job at the space hotel and plan to stay weeks, even months. What might happen to your body now?
If you picked E all of the above, you’re right. Whether it’s microgravity, space radiation or a combination of both, “your immune system definitely changes in space,” Lehnhardt said.
“Studies have shown that viruses that are that people already have before they go to space can reactivate in the space environment. Certainly, there is a possible concern for people in space to have infections more frequently, because of their reduced immune system,” he said.
Reactivation of latent herpes viruses, for example, have occurred on spaceflights. If you were exposed to herpes simplex on Earth, but never had a breakout, you might get your first fever blister in space. You might easily catch a cold, have increased allergic reactions, or break out with an immune-related skin condition like eczema.
“Especially when they stay in space for long periods of time, people can develop skin conditions like rashes, and many of those rashes may actually have an immune component to them,” Lehnhardt said.
Eyesight can also begin to fail, Lehnhardt added: “Some astronauts do experience a change in their vision in space that requires them to wear glasses in space when they may not have needed glasses on the ground. And we believe that’s related to the shifting of fluids in the body in response to the lack of gravity.”
When you come back to Earth after your visit to space, which of these changes to your body could you feel?
E, all of the above: Skin reactions are common, Lehnhardt said: “You’re just floating everywhere in space, even your clothing is floating. Sometimes astronauts would come back to Earth and say their clothing hurts them because it’s touching their skin all the time, and they are not used to that after months in space.
“Even the skin on the bottom of your feet changes in space,” Lehnhardt continued. “Because you’re not walking, all of those calluses on the bottom of your feet that protect you go away because they aren’t needed anymore in spaceflight.”
Nausea and vomiting is common when you return to Earth, as your inner ear and balance system readjusts to gravity.
“I had some issues with, like, pitching moments,” NASA astronaut Mike Hopkins told CNN. “It just felt like if I bent (over), I would fall right on my face.
“And in microgravity, you lose references to how much things weigh,” Hopkins said. “I remember when I first landed and I was laying in the Soyuz (the capsule used for landing), and I was just handing out our flight procedures. And that little book that maybe weighs a pound and a half felt like it weighed 25 or 30 pounds.”