Thread by @MaryRobinette

It's time to watch people try to go to space again today!

https://twitter.com/NASA/status/1266746446419841024

When you see the water tower in the screen with the rocket, know that it is Not Close to the rocket and is misleading about scale.

The crew cabin is comparable to being on the 23rd floor of a building.

By the way, "scrubbed" originated when orders were written on a slate and literally scrubbed off a schedule.

From multiple reports, when you put your feet in the air in the spaceship, it is followed by an urge to pee.

They are stuck in this posture for about two hours before launch.

They have MAGs (Maximum Absorbency Garments) that are basically adult diapers.

The helmets are 3d printed around the components and custom made for each astronaut.

These aren't rated for spacewalking, just to get people off the planet and back inside a spaceship.

Oh, look. Doug has stretched his legs out of the foot restraints.

Good sign that they are loading propellant!

T - one hour!!! The astronauts report being Go for launch.

The Go/No-Go poll at t-45 is checking in again with all the stations. The weather is going to be the big determiner.

The suits are cut to be comfortable when seated. They only need to walk a few times. That's part of why they appear to walk slightly hunched forward.

The Russian Sokol suits have the same thing, but the hunch is even more pronounced.

They enter the suits through a zipper from knee to knee in the crotch. It's a single piece, despite appearance.

One of the pieces that'll be given a full test for the first time is getting out of the spacesuits, while weightless, in a confined space.

They've practiced pieces of it, but the vomit-comet is only able to give about 30-seconds of weightlessness.

I'm watching this with a bunch of SFF authors at the #nebulas2020. Several of us just broke out some launch peanuts as a snack while we wait.

Here's why:

Someone asked me about Bob's glasses. Astronauts don't need 20/20 vision. Since being in space can affect visual acuity, there's no point in restricting people who need corrective lenses on the ground.

The glasses would have been cleared by NASA for safety.

If you want to play along after they are en route, SpaceX has a docking simulator with the ISS. Though the Dragon capsule can rendezvous without people -- which is how the cargo capsules work -- part of what Bob and Doug will test is manual flight.

iss-sim.spacex.com

I keep wanting to stand up to watch because I'm so nervous and excited.

LOX load is NOT smoked salmon. It's liquid oxygen.

One of the other things that will be happening is that the astronauts will hear sounds that they haven't heard before as the rocket is fueled.

The simulations are very, very good, but they aren't perfect.

The Apollo astronauts talk about being unprepared for the amount of shaking that happened during flight.

This will be the first time any human has heard and felt what it's like inside the rocket as it launches.

Less than ten minutes!!!

No commentary other than that.

They have pushbuttons on the black bar for the critical controls, but also a hand rest for comfort.

I think the fidgetting their doing now is partly to keep flexible for working. (Also probably nerves.)

INTERNAL POWER!!!

Propellant loads complete.

Get ready!

I didn't tweet at all during actual launch, because I just wanted to watch. Absolutely weeping with joy. What a beautiful launch.

Yay! For the landing! This part of the future is so amazing.

They are in orbit! The little stuffed dragon is their zero-g indicator.

It only takes about eight minutes to get to space.

After hundreds of thousands of hours of work.

Did you see the sunlight coming through the porthole and moving across the cabin during launch?

So beautiful.