Astronomy and space exploration

I've been watching for a while... Still waiting.

Prop loading going on right now. It's highly likely that we get a last minute scrub but they have been doing a lot of testing so I'm fairly optimistic. :D
 
Prop loading going on right now. It's highly likely that we get a last minute scrub but they have been doing a lot of testing so I'm fairly optimistic. :D
Seriously, I'm soooooo pissed off about all the delays, scrubs, etc. Of course, I understand that everything has to be as perfect as possible before it happens, but damn... :LOL:
 
Yeeeeeeeah, how surprising............ ¬_¬

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That was pretty f'ing awesome. That landing flip is nutty beyond belief considering this thing is around 50m long.

SN9 looks to be almost done. Shouldn't be too long before the next test. They're part way through building SN10-15 so plenty more test to go. Hopefully they'll speed up their test rate.
 
That was pretty f'ing awesome. That landing flip is nutty beyond belief considering this thing is around 50m long.

SN9 looks to be almost done. Shouldn't be too long before the next test. They're part way through building SN10-15 so plenty more test to go. Hopefully they'll speed up their test rate.
Yeah, it was soooo amazing!! I couldn't contain my excitement. I hope they could get a lot of useful data and put it to good use for their next attempt with SN9. Fingers crossed. It was almost perfect, this time.
 
It was pretty great, glad I stayed awake to watch it.

Did they lose an engine? The left rear engine (as seen from the engine bay camera) seemed to shutdown a bit into the flight, with some associated flame in the engine bay skirts. Maybe it was deliberate, but it seemed like they had unexpectedly little thrust in the final few tens of metres of the descent.

EDIT: Apparently it was a deliberate shutdown
 
@eloyc YEEES, I managed to watch it live just after my tennis class.

Amazing stuff. I was a little worried after the 1st engine shutdown because of the flameout and posterior fire, but when I saw the second engine go I was almost entirely sure it was programmed so I calmed down a little.

It's pretty incredible, if they had stuck the landing they would have sent a shock-wave,a massive one, throughout the industry although their competitors know it's only a matter of time.

I guess getting those tanks to properly feed the engines is very tricky due to the sudden change in orientation with all that fuel moving around but nevertheless there are ways to manage that and probably won't be a hard problem to fix.

But let's recap, yesterday we saw:

- Full recycling after wayward plane got too close to the restricted area
- 3 raptor simultaneous ignition
- Controlled shutdown + one raptor firing for 5 MINUTES. This is a full flow engine, this is like the pinnacle of liquid engine design considered almost impossible to build a couple of decades ago.
- Aerodynamically stable through the full flight with massive changes in pitch. I saw the control surfaces moving a little bit during takeoff, I know they use to do this with the shuttle to relief loads when needed, which was mentioned in the NSF webcast as well.
- Atmospheric engine relight
- Almost landing, it was very close, the terminal velocity didn't seem that high but that thing is massive, if touch down doesn't happen at Vt=0 that thing is going to blow up.

So next is:
- New alloy, I believe I heard on the NSF webcast that the SN9 is full 304L and they'll be moving to their proprietary design later
- Proving they can land it, I guess it probably take them a couple of tries
- Keep firing that raptor to iron out any issues left although it seems like is a very mature engine
- Suborbital flight, the big IF for me now is the TPS

If that is successful really all the major milestone left is building up super heavy and add more engines to starship to prove the structure can handle the load.

Exciting times ahead.

edit: TPS is Thermal Protection System, the tiles. Sorry for the acronyms XD
 
I guess getting those tanks to properly feed the engines is very tricky due to the sudden change in orientation with all that fuel moving around but nevertheless there are ways to manage that and probably won't be a hard problem to fix.

That's what the two smaller header tanks are for. They prevent sloshing/air bubbles of Doom. The CH⁴ one was under pressurised on landing, causing the Raptors to become engine rich. Like you say, shouldn't be one of the harder problems they have to tackle.
 
That's what the two smaller header tanks are for. They prevent sloshing/air bubbles of Doom. The CH⁴ one was under pressurised on landing, causing the Raptors to become engine rich. Like you say, shouldn't be one of the harder problems they have to tackle.

Yeap. Mmm... now I wonder, are the COPVs providing pressurization to the header tanks or just the main tanks? Could have been there an issue there as well. And if the CH4 tank was the one failing that would explain also the bright flame, if the remaining engine was running oxigen rich it may have started eating away the combustion chamber.
 
Yeap. are the COPVs providing pressurization to the header tanks or just the main tanks?

Neither. Starship uses autogenous pressurisation. A small amount of gasious CH⁴ and O² is syphoned off from the engines and fed back to the tanks to keep them pressurised.

The COVPs have nitrogen for the cold gas thrusters* and maybe to help the pumps spin up prior to ignition. Possibly used for some pneumatic stuff too?

* Later Starships may use beefier hot gas CH⁴ /O² thrusters. It'll mean the landing flip won't be quite so sporty.
 
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