Thread by @MaryRobinette

Let's talk about spacesuits, specifically Extravehicular Mobility Units, and being a #ladyastronaut.

The EMUs on the ISS were designed more than 40 years ago, with a 15-year shelf life.

11 of the original 18 are still in use.

Only 4 are on the ISS.

Those are the only EMUs.

https://twitter.com/lorengrush/status/1110290350005014529

Each suit is supposed to be completely refurbished on the ground after 6 years or 25 EVAs, whichever comes first but they often don't due to launch slips, failures, etc.

And they are still 40-year-old suits.

They are not designed to be refurbished in orbit.

When NASA says that there's not one readily available, it's sort of like...yeah. There's one up there, but we aren't sure it won't leak.

There have been 27 "significant" suit failures. None have been fatal, although 5 had the potential to be.

So, I'm really okay with the astronauts deciding that they would rather not take a task that is already INCREDIBLY RISKY and make it more so by rushing a refurbishing job.

But...

BUT... we should also talk about being a woman in space.

NASA used to have small, medium, large and extra-large suits. For budget reasons, the small and XL suits were cut.

However, many of the male astronauts could not fit into the L suits, so the XLs were brought back.

The small suits never were.

The hard-upper torso is a fiberglass shell. For best movement, you need to wear the snuggest suit possible.

If you're too small for your suit, you have problems reaching the dials on the front of the EMU, which means you can't do things like control suit temperature.

In addition, when using an EMU on Earth, you're subjected to "1G effects" you won't experience in space

Someone too small for their suit will drop inside it and be unable to see out of the helmet. Not a problem in space, but Earth is where they decide who gets to spacewalk.

All of which is to say that I'm very okay with the astronauts deciding to be safe.

I'm less okay with the causal chain that forced that decision.

PS. If you've read my novel FATED SKY, the padding that Elma used in the NBL scene was not something I made up. A real, actual #ladyastronaut had improvise that in order to use an EMU that was too big for her.

There was no provision in the shuttle era.

There still isn't.

Some FAQ:
-What about the Russian spacesuit?
The Orlan isn't modular, so can't be adjusted to fit different astronauts. The size range of cosmonauts is significantly narrower. Russia has only flown 4 women.

-Why didn't they prep suits for both women?
They did. But after McClain's spacewalk, she realized that she needed a medium to do her job safely. In addition to the things I mentioned in the thread, the suits are pressurized to 4.3psi so like working against a hard spring.

-Why does NASA use EMUs that are so old?
Here! A giant report about that and the problems.

oig.nasa.gov/docs/IG-17-018…

-Why didn't NASA know this before the announcement?

Until McClain did the spacewalk last week, she thought that a large would work. Think of this like wearing a pair of shoes that fits in the store, but it's different when you're on your feet all day.

-Why doesn't NASA delay the spacewalk so that the first all-woman milestone is met?

The ISS maintenance is vital. The fact that it's all-women is an accident of scheduling caused when the Soyuz launch failed last year, shifting the staffing.

-Why hasn't there been an all-woman crew before?
(Okay, no one has asked this, but y'all should.)
560+ people have been in space.
Only 63 of them are women.
The largest number of women in space at one time is 4.
The largest number of people in space at once is 12 men & 1 woman.