Artemis 1 Timeline

[Antares JS]

From my totally non-expert understanding of the engineering is that pre-launch they run some fluid through the engine to get the engine parts near fluid temperature so the material isn't "shocked" by the sudden flood of subzero liquid upon engine start for launch.

Precisely correct. We have to do the same thing with Antares.

That said, I will be shocked if this thing actually launches today.

 

[smstachwick]

All the birds that keep flying in front of the camera. I can’t help but think about how surprised they’ll be when they hear those engines fire up!

Assuming that happens today…

 

[cvanc]

Hey Antares JS, side note for ya: What determines which engines require chilldown? Do *all* liquid fuel engines above a certain size have it?

 

[Antares JS]

Hey Antares JS, side note for ya: What determines which engines require chilldown? Do *all* liquid fuel engines above a certain size have it?

I'm not certain, but I would imagine any engine that uses cryogenic propellants would need it.

 

[Marc_G]

Watching the live feed, but it's just video, no audio. Am I doing something wrong? All volume controls are on/unmuted

 

[smstachwick]

Turn the volume down, you don’t want to shatter your eardrums when the communications director speaks. There is no running commentary, only periodic announcements.

 

[CalebJ]

Turn the volume down, you don’t want to shatter your eardrums when the communications director speaks. There is no running commentary, only periodic announcements.

What feed are you using?

 

[smstachwick]

What feed are you using?

Tanking operations have begun, and so has my vigil. I’ve missed at least 1 historic event to Pacific Time Syndrome, and I’m not missing this one.



I’ll post an update if they switch streaming to a different video.

Try that one.

 

[mh9162013]

The Everyday Astronaut live Youtube feed has constant commentary...that's what I'm tuning into right now.

 

[neil_w]

Doing a daily word puzzle on my phone this morning and the very first word I filled in was “scrub”.

 

[Marc_G]

Thanks. I now just heard the announcements about the hold.

 

[smstachwick]

Doing a daily word puzzle on my phone this morning and the very first word I filled in was “scrub”.

Funny how this area of interest is at the intersection of cutting-edge technology and old superstition.

 

[cvanc]

The just announced this *is* the very first chilldown attempt.

 

[Antares JS]

Oof. I think I just heard them say that the issue they are having right now is something they were going to test during the WDR but didn't.

 

[OverTheTop]

OK. Just heard on the commentary that they didn't test this part of the process in the WDR4 due to some leaks in the plumbing to the flare stack.

 

[Antares JS]

OK. Just heard on the commentary that they didn't test this part of the process in the WDR4 due to some leaks in the plumbing to the flare stack.

Egg, meet face.

 

[smstachwick]

OK. Just heard on the commentary that they didn't test this part of the process in the WDR4 due to some leaks in the plumbing to the flare stack.

Would it have hurt to do WDR5?

 

[Antares JS]

Would it have hurt to do WDR5?

Probably would have meant another rollback followed by a rollout for WDR5 followed by a rollback to prep for the final rollout.

 

[modeltrains]

Watching the live feed, but it's just video, no audio. Am I doing something wrong? All volume controls are on/unmute

That feed is working for me because I can have the usual radio morning show playing and turn it down when commentator updates; thereby I get both things I want.

 

[Cape Byron]

Would WD40 help?

 

[smstachwick]

Well, the NET time we had yesterday has come and gone. Hopefully they get the countdown clock moving in the next 50 minutes, my rudimentary calculations indicate that’s the must-scrub time otherwise.

 

[smstachwick]

We’re scrubbed.

 

[modeltrains]

Scrubbed. Oh well, that's rocket science.

Note the quote in my signature line ...

 

[kuririn]

Makes my ignitor failure problems seem trivial.

Next available window is Sept.2, but they need to figure out the engine bleed problem first.

 

[Peartree]

One of the channels I was flipping through said that there was some kind of frost issue that might need to be addressed as well. Something about determining whether the unexpected frost on the tank exterior extended to the interior.

 

[OverTheTop]

Does anyone know what the cost of a WDR, including rollout to the pad and back, might be?

 

[Peartree]

Given the cost of the program thus far, I would think that the cost of an additional WDR would be lost in the noise. As it turns out, we paid for one anyway.

 

[Antares JS]

Something about determining whether the unexpected frost on the tank exterior extended to the interior.

Yikes. If there is frost forming inside a tank, that means there was moisture still inside it. If whatever system they are using to purge atmosphere and/or moisture from the tanks isn't working right, that's a huge issue.

 

[kuririn]

Yikes. If there is frost forming inside a tank, that means there was moisture still inside it. If whatever system they are using to purge atmosphere and/or moisture from the tanks isn't working right, that's a huge issue.

The commentator on the NASA live feed mentioned that engineers looked at it and determined that it was frost forming in a crack in the insulation due to ambient air, not an internal structural leak. Apparently that was a recurring problem on shuttle flights as well.

 

[Antares JS]

The commentator on the NASA live feed mentioned that engineers looked at it and determined that it was frost forming in a crack in the insulation due to ambient air, not an internal structural leak. Apparently that was a recurring problem on shuttle flights as well.

One thing I would genuinely like to know is why they are bothering with the foam in the first place. On the shuttle it made sense because you couldn't have that ice hitting the orbiter, but now that we are back to in-line rockets, is it really necessary? Classic space rockets did fine just shaking the ice off at liftoff.