Why are NASA's space suits so clunky?

Why are NASA’s space suits so much clunkier than the ones in science fiction or video games?

NASA has a real problem with the space suits that they stick their astronauts in to perform space walks. They’re massive, hard to get into and out of, and phenomenally unwieldy. The fingers on an astronaut’s gloves are so hard to manage that NASA has run competitions trying to get a better design that’s easier to work in. Ideally, we want to be able to stick people in suits that are easy to move around in, while still providing all the protection they would need. This is really, really hard to do.

If your suit is designed for the vacuum of space, you need to have a pressurized suit. Right now, this is done by inflating the suit with air, to compress the body to a point where the astronaut is comfortable, but not so much that it’s so tightly inflated that the astronaut couldn’t bend any of their joints. (This actually was a pretty severe problem for the first Russian spacewalker; his suit was so pressurized he couldn’t get back into his ship without letting some air out. He had to loosen a gasket on his glove to let the air escape, and then he got decompressed so rapidly he got a pretty nasty case of the bends, which is the same problem scuba divers run into if they surface too quickly.) You also need a suit that will provide some radiation protection, protection from tiny pieces of space junk, and on top of all that, you need your astronaut to be comfortable inside it and able to get in and out of it relatively easily.

On top of that, you have additional challenges if you want to land on a planet. Generally speaking, you don’t want to track dirt in from outside, if you’re on the moon or Mars. The dust on the moon (and we suspect on Mars as well) is such a fine powder that it can become embedded in your lungs and do quite a bit of damage. Mars dust might be even worse for you, since a lot of Mars’s surface material is so chemically toxic that it would burn you like bleach - not something you want in your lungs.

Physics is really not on our side for this venture. We’re asking for a pressurized suit that’s still easily bendable, which is also radiation-resistant, and easy to get into and out of, and durable. If you want to go out on the surface, you need to be able to decontaminate it completely. This space suit has to be a pretty impressive piece of technology.

The solution so far for spacewalks has been the kind of inflatable suit we’re used to seeing our astronauts in. Science fiction films and video games tend to prefer suits that are at least partially skin-tight. These aren’t completely impossible, and at least one person at MIT has been working on trying to design a suit that pressurizes the astronaut through mechanical pressure of the suit on the body, rather than the balloon method of air pressure. The mechanical skin-tight suit is really hard to make, because you have to get even pressure over the entire suit, and have it bendy enough to not restrict motion, and be durable enough to not break any wires if you fall on a rock or from bending the suit repeatedly. These skin-tight suits are also a lot harder to decontaminate, so getting all the dust off of them after a trip outside would be really hard to guarantee. NASA has also been testing a suit that you can crawl into through the back. This would be handy, because it means you can leave the suit attached to the outside of the base, and you won’t have to worry so much about getting the dust off. On the other hand, it’s still pretty clunky.

So unlike the science fiction films and video games, which can invent new materials to evenly pressurize an astronaut’s body, and new ways to decontaminate the suit so no one gets chemical burns from the surface dust once they come inside, while still protecting from radiation and puncture damage, NASA is stuck with the materials and methods that we have right now. We’re working on new methods and new technologies, but for the moment we don’t have anything quite as stylish as science-fiction can manage.

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