How does space travel affect the human body?

19 May 2015



Since the human body is evolved to conditions present on Earth, what are some of the critical challenges that the human body faces in space travel?


We put Roybath's question to Space Boffin Richard Hollingham...

Richard - Can I quote some Star Trek to you? Leonard "Bones" McCoy, I love this, "Space is disease and danger, wrapped in darkness and silence." It's horrible. It's really horrible. So, let's get to space first of all. Getting to space, you've got to overcome gravity and the G-force is pushing on your body. There's a James Bond film where he goes spinning around and it must be Moonraker where he spins around on the centrifuge.

Chris - Have you been in one of those?

Richard - I have been in one of those. Horrible. I was rubbish. I was absolutely.

Chris - How many Gs did you pull?

Richard - I think I only managed about 3.

Chris - How many would a real-life astronaut?

Richard - A real astronaut actually, probably with most spacecraft - now, you're looking at 3 or about 4 or something like that. If the Soyuz - so, we talked a little bit about Russian rockets going wrong - if the Russian rocket goes wrong, the Soyuz they use, the escape system essentially will ping it off in a trajectory and then you are heading towards almost 10G, something like that. It's really nasty.

Chris - Is that survivable?

Richard - Yes-ish. It is survivable for a fully trained astronaut, absolutely. There's no problem at all.

Chris - What do they do to people then to train them, to stand that?

Richard - Well, they spin around in a lot of centrifuges. It's also about the way.

Chris - If you survive then you're destined to be an astronaut. If you die in the process, you're probably not going to make it.

Richard - The main reason - yeah, 10G is absolutely horrible but the way a spacecraft is designed, you'll always see them lying on their backs. The reason for that is because the force will go through their chest. So, it won't go from head to toe.

Kat - So, it's not compressing your spine down where it's kind of squashing you.

Richard - Not doing anything like that, not hitting your head. It's deliberately designed to go through your chest. Obviously, the way the suits are designed are designed to pull these sorts of G-forces. Actually, the centrifuge I went in which is an ancient centrifuge at Farnborough in southern England, it has actually designed to go up to 18G.

Kat - Okay, so we go to space, you've withstood the Gs. What's up there?

Richard - The next short term problem is nausea. Almost all astronauts - however well experienced, however well-conditioned, however many times they've done parabolic flights and what's called the vomit comet which are these planes that goes in this parabolic trajectories around - they get sick. The Soyuz spacecraft which is the only one you can use to get to and from space right now, it rotates slowly. So, you got a window there. So, you're in the spacecraft that you're suddenly feeling weightless, but also, the spacecraft around you is rotating. So, you can't even look. You know, they always say if you're on a roundabout or something.

Kat - I get so badly travel sick. I'm actually feeling you. I've been sea sick on a pedalo. I get really sick.

Richard - They say if you feel ill, you don't look out the side you look at the front. But imagine that this thing is spinning. So, imagine your car that's spinning as well. So, that's that. Once you're in space, the other thing that happens is your fluids tend to move around your body. You're not subjected to gravity and they tend to swell in your head. So, astronauts really do have big heads. So fluids tend to pool in your head. So, you get this feeling of permanent head cold in space. More serious are things like muscle loss and bone loss. Again, it's down to gravity.

Kat - So, this is when you're in the zero G environment for a long time?

Richard - Yeah. When you're in this microgravity environment, you've got loss of bone, loss of muscle, which is why astronauts have to exercise. I mean, they had to have a serious amount of exercise.

Kat - You've got to get some impact going on your muscles.

Richard - Hours of exercise, yes. So, they're attached with lots of bungee cords, elastic, all sorts of other things to treadmills, they're shifting weights. And designing a space station to move weights is quite interesting. If you stuck weights inside and move them around the space station, if you move the weight, the space station moves. Because you've got equal opposite forces. So, they're very clever designs to make sure if they're moving away, they don't shift the space station's orbit or anything like that. It's also a problem with the urine recycling system on the International Space Station. in that you get a build-up of calcium in the system as well as a result of this calcium being lost from astronaut's bones. Chris has mentioned that the radiation danger in space. You're pretty well protected in low Earth orbit because you're in this realm really of the Earth's magnetic field. You're protected by this magnetic bubble around the Earth. But if you venture beyond that, then you can get zapped. Eyes start to deteriorate in space. You can get brain damage from cosmic radiation. Disease, the immune system deteriorates in space. They don't entirely know why. There's been lots of studies on that. There's also psychological effects of being in space. So, there's issues of depression. So, right now, the International Space Station, they did an experiment on comfort foods. So, they're giving astronauts...

Kat - Aw, they're sending them chocolate and stuff?

Richard - They literally are using chocolate pudding. So, they're giving them tasks they don't like to do on the space station. So, they make them hoover the space station...

Kat - You're got to go and clean up the urine thing.

Richard - Exactly, yeah. It is that sort of thing. "Go clean the toilets."

Chris - Sounds like what I do with my kids.

Kat - "Then I'll give you some chocolate."

Richard - They're looking at this because if you're going to go to Mars, we're looking at, at least a 2-year mission there and back. So, they're looking at, "if you vacuum and you're don't get any reward. How do you feel? If you vacuum and you get a nice chocolate pudding." They love the chocolate puddings.

Chris - But it looks really nice - that's your reward. Look you've made a good job on that. Everyone gives you positive feedback.

Kat - No, I want chocolate basically.

Richard - No one thinks that, Chris.

Kat - I think for me, my biggest issue with it would be cooped up with that many people. I mean, I get travel sick, I'd have to contend with that. I would just want to kill people basically.

Chris - Well Kat, the feeling might be mutual.

Kat - I've been in the studio with you guys for an hour and I am kind of ready to kill right now.

Richard - Well, you have got the view. I mean, there are lots of compensations of being in space. You can look out at the Earth below. It's the best view in the world.

Chris - But not in the world!

Richard - Well, the best view of the world. So, there are also some fantastic compensations.

Kat - Would you want to go into space?

Richard - I would like to be in space. I don't want to get there. I think the getting there, having been on the centrifuge, having sat inside a Soyuz simulator, having felt - because how cramped. It's the claustrophobia that's an issue, but obviously, they don't select astronauts with claustrophobia. That's a fairly fundamental thing. But wouldn't that be amazing to sit inside the International Space Station and look out to that amazing, almost like bay window, on the world?

Kat - How about you, Chris?

Chris - I think I'm with Richard. I'm scared about the journey. I'd quite like to have the experience but I don't think I'd like the health consequences, now I know what they are. Thanks, Richard.

Kat - Very briefly Max, space or not?

Max - Yeah, I agree. Getting there wouldn't be very good. It took me about 19 years to pluck up the courage to go on roller coaster. So, I'm not sure how I would handle it.


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