Space and Science BS Thread

Need to get the right context. How much liquid hydrogen does it take to fill a stock tire?

 

It’s been said before...

F9 is living up to the Shuttles promise of rapid reusability.

https://www.teslarati.com/spacex-falcon-9-halves-space-shuttle-record/

The author conjectures single digit days to turnaround by the end of 2021.

 

The lift isn’t the concern; it the hard thud on the landing.

 

https://twitter.com/elonmusk/status/1357248581581889538?s=19

 

Didn’t seem lIke SN8 restarted the Raptors earlier?

 

I think it was camera angle. Sn8 never attempted to light 2 and then transition to 1 though.

 

That was a short twitter break.

 

I think they both attempted to light 2 Raptors for the landing flip...

In any case, this is a pretty neat above/below comparison:

https://youtu.be/exIBPHJ_FrQ

 

SN8 definitely relit two raptors for landing, you can see the separate rocket exhausts when they are gimbaling to keep it vertical and see one either flame out or shutdown for the single engine landing.

 

They relit 2 raptors for both attempts. SN8 kept both lit until death and had much smoother control. SN9 they lit 2 raptors, and then intentionally shut one off. They shut it off too early and a single was unable to stop the momentum of the last part of the flip.

 

I don’t think they had a choice to shut it off. It was blowing out pieces and probably shut itself down automatically.

 

Both SN8 and SN9 look to have had an engine fail early but for different reasons. SN8 flamed out due to fuel pressure problems, SN9 looks like the engine failed to relight properly and then the powerhead caught on fire.

 

They said in their live stream before the ignition that they were going to light both and then transition to 1. I think they wanted to use 2 to shift it upright from the belly flop and then only 1 for the actual touchdown.

 

Interesting. Maybe the chunk that flew out put a monkey wrench in that plan. Thanks.

 

“Game on for the Artemis Program” from a current ARS Technica article.

Look it up if you’re interested.

Good to know some continuity will be maintained

 

That's a shocker - would not have bet that.

However, that is great news for us!

 

Maybe.. though 'select now, don't delay' could very well mean Blue + Dynetics.

 

https://spacenews.com/op-ed-the-faa-and-spacex/

 

3 Raptor landing burn for SN10..

https://www.teslarati.com/spacex-elon-musk-talks-starship-sn9-explosion/

 

I guess if you can't get two to light reliably you try three so you end up with two working hopefully.