# Puncturing space suit during EVA. What would happen?

What would happen, if the space suit of a spacewalking crew was punctured during the extravehicular activity (EVA)? What are the chances of this happening? Has this already happened to anyone in the history of space exploration?

• possible duplicate of Reaction to taking a glove off in space Jul 31 '13 at 8:25
• @coleopterist Not entirely. Taking a glove off is kind of different from puncturing a suit. The latter has happened before. Life support kicks in with all its reserves and people return to the nearest airlock. This is worth a good individual answer. Jul 31 '13 at 11:52
• If anyone is thinking about the stunt portrayed in the movie "The Martian", I'd like to point out that it did not happen in Andy Weir's original novel. Jul 5 '16 at 3:07
• They would slap on a bit of duct tape, and ask mission control if they really have to abort the EVA just because the safety regs advise they do so. Jun 27 at 12:06

Chances: Murphy's law - bad things eventually happen. Reasons: Besides (micro-)meteorites, as mentioned by @TildalWave, the risk is with the astronauts themselves. EVAs are for repairing stuff, 'plumbing', handling tools and equipment etc. It is natural to break stuff while you work.

In terms of numbers, although there were plenty of EVAs in history, everybody survived them. And besides problems with heating and cooling, water at the wrong place inside the suit or just overpressure, there have never been severe problems yet. So it is hard to put a number on it.

Space suits (just like manned space crafts) are designed to handle leaks or holes of a certain size for a certain amount of time. In a space craft, the idea is to give astronauts time to 'jump' into their pressure suits or another available safe space craft before they run out of air. In a suit, the idea is similar – provide enough time for a safe return to an air lock.

If you are interested in details, have a look at the specifications of space suits for EVAs. I found an example for the Russian Orlan suit. The system is referred to as "leak compensation system" (section 4 | page 28).

Please note that there is virtually no absolutely airtight suit. There are just too many connections and o-ring-seals. All suits therefore leak permanently to some degree. If the amount of leaked air increases above 'normal', for whatever reason, a suit's life support system can increase the amount of air pumped into the suit at the expense of the duration of an EVA.

Real life incidents of leaking or punctured suits are rare. As far as I know, there are no documented cases of suits loosing air rapidly in space. But keep in mind, every suit leaks, so there were in fact a few suits leaking more than they should. Partially punctured suits are also a known problem. A famous modern example happened on STS 118, where two of the five layers of material of the glove of an American suit were punctured. Another interesting incident, although initially unnoticed, happened on STS 37.

I depends on what caused the tear / puncture and how fast the depressurisation is due to it.

If, for example, the puncture was caused by a micrometeorite, the relatively fast depressurisation of the space suit might not be of the greatest concern for the unfortunate astronaut, as the micrometeorite could pass through the astronaut's body at speeds possibly an order of magnitude greater than a bullet exiting a shotgun can travel, causing anything from punctured through projectile wound, to instantly internally liquefying the poor astronaut's body in an unrecognisable mix of all of his/her internals, if the micrometeorite hits the space suit at extreme velocity relative to the movement of the EVA engaging astronaut and is big enough (where total energy released is $E_\text{k} =\tfrac{1}{2} (m_\text{in} - m_\text{out})(v_\text{in}-v_\text{out})^2$ where $m$ is mass and $v$ velocity of the penetrating object).

However, assuming the tear / puncture was made by other (non-lethal on their own) causes, such as parts of the space suit unwittingly getting trapped between some equipment, brushing against a sharp object, or similar, then the problem becomes one of trying to temporarily re-pressurise the space suit's internal pressure with whatever life support oxygen and other gases in the breathable mix are left available, hopefully adding to the suit's internal pressure faster than the depressurisation is occurring and moving to the nearest airlock as soon as possible (as @ernestopheles mentions in his comment). If the puncture is within the reach of the astronaut (or one of his/her team), they might also try to apply pressure on the puncture manually, or by applying some adhesive patch in hope it stops or limits the speed of the depressurisation.

Frequency of such micrometeorites is tough to judge, and depends on where the EVA is taking place. On planets with at least some atmospheric pressure, chances are they would burn up upon entry to the planet's atmosphere. Around Earth's orbit, there might be bigger risks involved also due to loads of space junk orbiting Earth, that we've put in space during previously aborted or retired missions, lost tools, e.t.c. that might be orbiting the Earth due to inertia.

As for the other part of your question, if this already happened to anyone, I don't have any knowledge of such accident happening to anyone while actually in space, but it did happen while testing space suits and EVA equipment here on Earth, in relatively controlled environment of a vacuum chamber, which was luckily repressurized fast enough not to cause permanent health issues or even death to the test subject involved. See this answer for more information on that accident and what would happen, if your body is exposed to the vacuum of space.

• You need to apply a lot of pressure on a puncture for a significant effect to occur. About the patch - I think you are talking about using one while the astronaut is 'outside' (?). There actually are adhesive materials, which work in a 'vacuum'. But it is a nightmare working with them. Unfortunately, this is nowhere near a quick emergency solution while performing an EVA ;-) Jul 31 '13 at 14:38
• @ernestopheles - I'd imagine it so too, yes. Their most immediate course of action should be getting the astronaut into the airlock ASAP and re-pressurize it. But if that is not possible within a few tens of seconds of the puncture happening, then they might try other ways to stop or limit the effects of depressurisation while pushing towards the airlock. But a question now - is there any research in using some within the suit adhesive that would release on sudden pressure change, or compartmentation of space suits, like in some advanced automotive tires when they are punctured? Jul 31 '13 at 14:48
• You mean materials, which can (temporarily) heal themselves? I have never dealt with space suits, so I can not answer this directly. Please ask someone else - preferably life support engineers. However, I worked with vacuum chambers - which is when I learned to admire space suits. I can not think of any (adhesive) material, that would do the trick in a vacuum. In terms of compartments, think about the possible pressure (equals force divided by area) gradient and the limits of the human body. Jul 31 '13 at 15:40
• The impact speed of a micrometeoroid could indeed be an order of magnitude higher than that of a shotgun slug, but the average micrometeoroid would also be a few orders of magnitude less massive than the average shotgun slug (and kinetic energy depends on mass as well as speed). (Note that getting hit by a shotgun slug is itself generally nothing to sneeze at, although I - fortunately! - have no direct, personal experience of this.) Jul 20 '19 at 21:46

In fact there was a puncture incident during one of the earlier Space Shuttle EVAs. Glove got punctured due to it's fabrication/assembly defect. The thing was that astronaut didn't even notice until after the EVA he found strange red spot on his hand. Hole was not big and his skin sealed it, so air leak was below any alarm levels. And astronaut was excited enough (it was his first EVA) that he didn't notice.

• Can you specify which mission, and possibly provide a reference? Thanks. May 7 '14 at 12:41
• I believe that would be the STS-37 EVA and the astronaut in question either Jerry L. Ross or Jay Apt. Here's Geoffrey A. Landis sci.space.tech post (archived) adding Gregory Bennett's account of the incident. Similarly, though not in orbit, Joe Kittinger, Jr. lost pressurization in his right glove during a high-altitude balloon parachute jump at ~ 19.5 mi altitude. The hand became stiff, painful and swollen to double its normal size, but later fully recovered. May 7 '14 at 13:24