Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us all expand our scientific vocabularies together. Today’s term is:
MECHANICAL COUNTER PRESSURE
Turns out the costume designers of many classic, B-movie Sci-Fi flicks may have been on to something. Space adventurers of tomorrow may actually end up wearing snug, form-fitting spacesuits. For legitimate, practical reasons (not just fan service!).
Spacesuits need to accomplish several things: provide breathable air, regulate your body temperature, keep you pressurized…. For that last part, current space suit designs rely on air pressure. Essentially, spacesuits are human-shaped balloons filled with enough air to replicate atmospheric pressure.
In the future, spacesuits might be made of a web of “coils.” When activated (using an electrical current, perhaps) these coils would contract, morphing around all the curves and contours of your body, physically compressing you with enough pressure to simulate atmospheric pressure.
This process of being squeezed and compressed by your spacesuit is known as “mechanical counter pressure.” Parts of a mechanical counter pressure spacesuit will still have to be pressurized: the helmet, for obvious reasons, but also the gloves and boots. Mechanical counter pressure could severely damage the fine bones of the fingers, wrists, ankles, and toes.
So why would you want to wear a mechanical counter pressure suit?
- Because your spacesuit would weigh a whole lot less.
- Because your spacesuit would be a lot less bulky, giving you a wider range of motion while working in space.
- Because if your spacesuit is punctured or torn, you won’t depressurize. The coils will remain contracted.
- Because you want to look good for all the alien hunks/babes you’ll be meeting in space.
Unfortunately, mechanical counter pressure suits are still very much on the drawing board. The biggest problem seems to be getting the coils to contract and stay contracted without a continuous electric current running through them. There’s not much risk of getting electrocuted by your suit, but the continuous current would eventually make your suit hot. Very hot.
So NASA’s next generation of spacesuits will probably go in a different and less sexy direction. We’ll talk more about that next week.
P.S.: Just to clarify, when I say your spacesuit would get very hot, I’m not referring to the sexy kind of hot.
Links
Shrink-Wrapping Spacesuits from MIT News.
Futuristic Skintight Spacesuit May Shrink-Wrap Astronauts from Space.com.
Future Spandex from TV Tropes.
Planet Pailly 
Some years ago, I was surprised to learn that astronauts on the ISS, prior to a space walk, have to spend several hours in the airlock while the air pressure is brought down. Apparently, if they tried to spacewalk with the suit pressured to normal pressure, they wouldn’t be able to bend the suit’s arms or legs. I assume reentry requires a similar airlock session. (I suppose the Apollo astronauts were able to use the lunar lander as a pressure chamber.)
This seemed to invalidate a common sci-fi scenario of the hero quickly donning a spacesuit for some emergency or other.
I wonder if a coiled spacesuit might sidestep that issue.
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You know, I’d heard about that too, and it was presented to me as yet another on-going problem with human space exploration. But in research this post and several posts to come, I found out this is really an issue with NASA’s current spacesuit design (the EMU or Extravehicular Mobility Unit).
Apparently back in the Apollo days, you could put on your spacesuit in just a few minutes, if you had to… because in an emergency, you might have to. It seems like NASA is trying to get back to that with its next generation spacesuits.
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Interesting. Looking forward to the next posts.
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