What Happens To The Human Body In Space

What Happens To The Human Body In Space

In 2016, astronaut Scott
Kelly returned to Earth after nearly a year on the
International Space Station. But when he came back,
he was 2 inches taller. So, what exactly happened up there, and what does that mean for
the future of space travel? If you’re planning a
trip to the International Space Station, be prepared
to feel weightless. The station orbits the
planet every 90 minutes, moving at more than 17,000 miles per hour. That’s 30 times faster than
a commercial jet aircraft. As a result, astronauts on
board live in a constant state of free fall, or weightlessness. Garrett Reisman: Being up there
in microgravity is awesome. It’s, like, the coolest thing, because it’s like you
have the power to fly. Narrator: That’s Garrett Reisman, a former NASA astronaut who’s
logged 107 days in space. There are a few immediate
side effects, he says, when you first experience microgravity. Reisman: So the first
thing you really feel is you feel kinda sick. You don’t feel very good
those first couple days. It’s kinda like being airsick or seasick. We call it space-adaptation sickness. Your vestibular system, your organs that provide information to the brain about your rotation and your acceleration, they’re not working that great
without being in gravity. Narrator: Without gravity
working on your body, your bones and muscles
start to break down, too. In fact, bone density
drops by over 1% per month. By comparison, the rate of bone loss for elderly men and women is
around 1% to 1.5% per year. And, because it doesn’t take much effort to float through space, your muscles lose strength
and endurance pretty quickly. Reisman: You have to work out every day. So, they scheduled two hours
a day pretty much every day while I was on the space
station for working out. What we found was, if you do
enough resistive exercise, you can halt the effects of the bone loss and the muscle atrophy. Narrator: Without gravity
pulling them down, fluids pool in the body,
tricking it into thinking it’s carrying too much water. As a result, astronauts have to pee… a lot. This makes it easy for
them to get dehydrated and develop kidney stones. Reisman: So, you have
a shift in your fluid. A lot of the blood volume that
normally is down in your legs ends up up here, and
your chest kinda puffs up and your face puffs
up, and you can see it. If you look at pictures of
us on the space station, it looks like we put on
some weight or something and we’re all puffed up. Narrator: Swelling in the upper body puts pressure on the eyes as well, which can cause vision problems. Reisman: A lot of us, including myself, had a shift in our vision
while we’re up in space. You start out, everything was fine, and all of a sudden things get blurry. We could see the effects of it. We could see swelling in the optic nerve, we could see folds in the cornea, but we’re still not 100% sure exactly what’s causing
it and how to stop it. Narrator: With all the
challenges of space travel, one benefit is you actually get taller. Reisman: So, yes, you do get
taller when you go to space. It’s the whole reason I
signed up for this job. Your spine is being compressed by gravity. So, when you go into the
microgravity environment and you no longer have any
kind of compressive loads on the spine at all, it stretches. I grew about an inch. Astronaut: Woo-hoo! Narrator: Without gravity
working against it, the heart doesn’t have to work as hard to pump blood throughout the body. Over time, this could lead to the heart actually decreasing in size. Reisman: There is an effect
on the cardiovascular system about being up in space. So you do get a reduced
aerobic capability. You can be in great shape, and after being up in
space for a couple days, you might get on the treadmill,
and you might be like, “Man, I must not have
been hitting the gym.” Narrator: The immune
system also takes a hit. Researchers discovered
that a lack of gravity weakens the functions of T cells, which play a crucial role
in fighting off diseases. Another concern is cosmic radiation. Astronauts on the station are exposed to over 10 times the amount of radiation that we get on Earth. Reisman: At a couple hundred miles, we’re well above the atmosphere, but we’re still well below the
magnetic field of the Earth. But we still get a large bit of protection from that magnetic field. In fact, you could tell, because
when you close your eyes, you see little lightning bolts, and that’s actually a result
of some of the radiation hitting your eyeballs
and releasing photons. Narrator: Artificial shielding on the ISS only partially protects
astronauts from harsh radiation, leaving them more susceptible to cancer and other diseases later in life. Finally, astronauts must
also be able to handle the psychological challenges
of confinement and isolation. Reisman: So, there is
a psychological aspect to being in space, both
because of the fact that you’re isolated from
the rest of humanity, it was really strange to
be looking out the window at billions of people down there that had no way to get to me. When I was there, I only had two crewmates at a time on the space station, so if you don’t get along with somebody, that could be bad, because you don’t have too many choices there
in making new friends. Narrator: And, without
a 24-hour sleep cycle, astronaut circadian rhythm is thrown off, which can cause more stress
and lead to sleep disorders. Reisman: You’re taking jet
lag to a whole nother extreme. Well, the weird thing is
that you go around the planet once every hour and a half. So every 45 minutes, the sun
is either rising or setting. So you can’t, like, tell what time it is by looking out the window. Narrator: So, what does all this mean for the future of space travel? Well, a trip to Mars
would expose astronauts to even more dangers than those on the International Space Station. They would face higher
levels of radiation, shifting gravity fields,
and longer travel times, which would compound all
of the negative effects of space on the human body and mind. Reisman: I think the biggest
issue we gotta deal with is the radiation. We don’t know precisely
what that exact radiation does to human beings. But what does gamma rays
or what does heavy ions, what do they do human tissue? We don’t really know. Narrator: Right now, NASA and
other research organizations are working to develop better technology that protects astronauts
against these hazards, so maybe one day humans
might make it to Mars.

63 Replies to “What Happens To The Human Body In Space”

  1. the #1 problem for reaching Mars is actually bone density loss due to lack of gravity. The duration of the journey is so long that a human will have irreversible damage to their bones. How did they miss that..?

  2. The height increase really bums me out but I guess it’s not that bad since it goes back down once you come back to earth

  3. This should be from science insider because technology doesn’t really have that much to do with body changes in space so it should be science insider instead of tech insider

  4. Nothing happens. Everybody knows that humans can't go to space because of the Van Allen radiation belt. NASA is a total fake.

  5. Two questions for anyone capable of answering them, please: If we move in slow motion in zero gravity bc we are weightless, why do all of the Apollo astronauts also move in slow motion, despite the moon's gravity being 1/6th that of the earth's? The same weight is lighter but why would something like walking, driving or waving an arm, be in slow motion? And, in looking at Apollo footage recently, I came across a clip called: Hammer retreival, Apollo 16 [sic] – Just watch it. He drops a hammer and then makes repeated, higher and higher jumps upward in his attempt to grab it. Why couldn't he just drop down, on one knee?

  6. Space Kills human bodies, in seconds. We are not talking about the effects of Space here. The effects they are discussing in this presentation involve what happens when you go live in a cheap trailer trash Space Habitat for any extended period of time. The fact that Humans have been making these tin cans and have failed to build something big enough to spin and provide artificial gravity should be pointed out at every opportunity, and that is what this is. Yes, If you go live in a weightless environment you are not only dumb but you will lose muscle and bone mass.
    It's time we man up and build a wheel in the sky. https://www.youtube.com/watch?v=Q7f5za5tz3w

  7. We


    No business

    Being in space.

    Send probes with robot humanoid android drones with cameras and total human emulation,and explore the universe with a avatar VR holodeck
    Directing Robot Astronauts…..
    from earth!

    Intergalactic Space travel is an inevitable impossibility… unfortunately. People who try to colonize planet's….

    Wil ALL Die.

    We are earthlings on a molecular level.we were designed and created for Earth and Earth only.
    Get over it.

  8. The Earth does not rotate.

    Here is the proof:

    Start up the primary navigation system on any stationary commercial aircraft anywhere on Earth. Allow it to come to a steady state. Observe the readings for yaw, pitch, and roll. Allow the navigation to system to run undisturbed for 3 hours. During that time, the Earth allegedly rotates 45 degrees. At the end of that time, observe the readings for yaw, pitch, and roll. They will not have changed.

    The Earth does not rotate.

    You have been deceived.

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