andrewas Posted February 25, 2015 Share Posted February 25, 2015 If the first problem is solved, you could get around the latter by having a conventional pressure suit with counterpressure limbs. Or even just counterpressure arms, not sure how much leg mobility is valued in EVA. Link to comment Share on other sites More sharing options...
Beowolf Posted February 25, 2015 Share Posted February 25, 2015 I wonder if we couldn't get around this problem by using modern smart materials. Say you build something that expands when you apply a current. So you grab a spacesuit, hook it up to a power source to loosen it up, get in, and unplug it so it grips you tightly. Worst case scenario they'd have to cut you out of the suit if it somehow fails to loosen. And its a lot faster.It's my impression MIT's current work involves smart materials, so good idea! Link to comment Share on other sites More sharing options...
-Velocity- Posted February 26, 2015 Share Posted February 26, 2015 Sun's radiation would give you 2*1360 W at Earth's distance. Not sure how much that'd harm you, receiving additional ~ 2700 W every time. For instace, that's more than the wattage of most household things...It wouldn't be a problem, other than the ultraviolet light (which would rapidly give you a severe sunburn). You get around 1000 W/m^2 at sea level. As other people point out, sweat evaporates very quickly in vacuum, so you'd stay cool. Link to comment Share on other sites More sharing options...
Cirocco Posted February 26, 2015 Share Posted February 26, 2015 (edited) ok my two cents:Is the cold in space actually a problem for humans?Not really. Either you're in a full spacesuit which insulates you so much that heat is more likely a problem, or you're subjected to the vacuum of space, in which case the cold will the very least of your problems. A vacuum is actually a very good insulator, other stuff would kill you long before the cold does.Would it be possible to survive space in just face protection?yes, for a very short period of time, under a couple of specific conditions (not too close to a star or subjected to another source of deadly radiation, stuff like that) and the face protection probably wouldn't do much for you. As stated several times before, if air finds itself into your lungs with any significant pressure while the outside of your body is subject to vacuum, it would almost certainly cause lung damage due to the pressure difference. You would be much better off making sure you exhaled all air prior to getting blown out the airlock.Some back-of-the-envelope maths for reference: atmospheric pressure is about 100 kilopscal at sea level (give or take a couple hundred pascal). That's 100 000 Newton per square meter. Given that the force that a single kilogram (about 2 pounds for you empirial folk) exerts on earth is about 10 newtons and assuming that your chest is about 1 meter squared, if you're breathing atmospheric pressure air through that facemask of yours, you're looking at a force equivalent of 10 000 kg (about 20 000 pounds) pushing outwards from your lungs. There's a reason NASA only inflates their pressure suits to about 30% atmosphere (they use near-pure oxygen to fill them I think. Could be wrong about that)And if so, how long? What would kill you? Most articles I've read on the subject agree that under "ideal" conditions, humans would be able to survive about 30 seconds of outer space exposure without permanent damage. They would probably be the most unpleasant 30 seconds you've ever experienced in your life and "without permanent damage" is assuming you haven't been bombarded with cancer-inducing high-energy particles and radiation and haven't encountered any insta-killing conditions. As for what would kill you? Oxygen depravation, as has been stated before in this thread. Edited February 26, 2015 by Cirocco Link to comment Share on other sites More sharing options...
YNM Posted February 26, 2015 Share Posted February 26, 2015 Sun's radiation would give you 2*1360 W at Earth's distance. Not sure how much that'd harm you, receiving additional ~ 2700 W every time. For instance, that's more than the wattage of most household things...It wouldn't be a problem, other than the ultraviolet light (which would rapidly give you a severe sunburn). You get around 1000 W/m^2 at sea level. As other people point out, sweat evaporates very quickly in vacuum, so you'd stay cool.Hmm... I don't want to poke at this equation but I guesstimate the quickly harming ones (shorter than visible ; IR is harming but you need a very long exposure) are ~10% of the total (bolometric) radiation. That's still ~260 W of them... the 1000 W on sea surface is largely (~ 75%) in visible and radio (which are not harming at all, bar direct seeing at the sun). Link to comment Share on other sites More sharing options...
vger Posted February 26, 2015 Share Posted February 26, 2015 I wonder if we couldn't get around this problem by using modern smart materials. Say you build something that expands when you apply a current. So you grab a spacesuit, hook it up to a power source to loosen it up, get in, and unplug it so it grips you tightly. Worst case scenario they'd have to cut you out of the suit if it somehow fails to loosen. And its a lot faster.I think even smart materials might result in this problem, having to 'cut' out the suit later.This sounds like something that would terrify me. Give me the bulky suit so I don't have to worry that if one square inch of material isn't tightened just right, it's going to spell catastrophic failure.But... I remember this being a problem with early flight suits as well. The ones that are designed to help your body distribute blood better during high-G maneuvers. And they finally figured that one out. Link to comment Share on other sites More sharing options...
Skyler4856 Posted February 27, 2015 Share Posted February 27, 2015 (edited) 2) The other problem was male crotches. Testicles don't like being individually wrapped really tightly, and if there was any gap left at all the testicle would painfully expand into it. They couldn't work out any sort of cup design that'd hold against the pressure difference and not be too painful to wear. In his novels, Pournelle thought women's breasts would be the problem, but they said it was just like a sports bra. Men got the bad end of the gender stick this time.Any reason why inflatable underwear couldn't be used in tandom with the the elastic system? Edited February 27, 2015 by Skyler4856 Link to comment Share on other sites More sharing options...
monstah Posted February 27, 2015 Share Posted February 27, 2015 You have other holes in your body- your ears, your butt, your eyes- and those need to be plugged too. Plug your butts, people, today we're going to space. Link to comment Share on other sites More sharing options...
Cirocco Posted February 27, 2015 Share Posted February 27, 2015 Plug your butts, people, today we're going to space.I... just... that visualisation...I have no words... Link to comment Share on other sites More sharing options...
Sirrobert Posted February 27, 2015 Author Share Posted February 27, 2015 I... just... that visualisation...I have no words...Mission accomplished Link to comment Share on other sites More sharing options...
sal_vager Posted February 27, 2015 Share Posted February 27, 2015 inB4 items are mentioned that are for rectal use only.Remember to keep it clean guys Link to comment Share on other sites More sharing options...
Beowolf Posted February 28, 2015 Share Posted February 28, 2015 (edited) Any reason why inflatable underwear couldn't be used in tandom with the the elastic system?I don't know. The MIT version is called "Bio-Suit", and Googling got me a couple of recent hits. So at least it's still ongoing. Oh, and apparently there was a 2013 TED talk. I'll have to check that out.Edit: I can't watch it right now, but found this gem: A 1-hr presentation by the professor in-charge. Skipping through, it looked great! Edited February 28, 2015 by Beowolf Link to comment Share on other sites More sharing options...
ian976 Posted December 26, 2017 Share Posted December 26, 2017 Hey, latest study says that astonaut's body temperature rises in space I could actually be the reason because it is cold there? Anyway, astronauts that were tested on temperature had around 40 degrees! Link to comment Share on other sites More sharing options...
Snark Posted December 26, 2017 Share Posted December 26, 2017 2 hours ago, ian976 said: Hey, latest study says that astonaut's body temperature rises in space I could actually be the reason because it is cold there? Anyway, astronauts that were tested on temperature had around 40 degrees! Hello, and welcome to the forums! Just a couple of notes, though: The bit about body temperature rising in space is about living in a spaceship or spacesuit in zero gravity. This thread is about humans being exposed to vacuum. Please note that the thread is nearly three years old. Everyone involved in the original discussion has presumably long since moved on to other things. Accordingly, locking the thread to prevent further confusion, since this thread is long since "done." If you'd like to talk about the topic, feel free to spin up a new thread. Cheers, Snark Link to comment Share on other sites More sharing options...
Recommended Posts