Astronomy and space exploration

cheapchips said:
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.
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Nice, I didn't know they were already using autogenous pressurisation for the tanks. I though there were going to use COPVs until they moved to the orbital vehicles, can't blame them after all the issues they had with them.

cheapchips said:
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?
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My guess is probably is just RCS and, maybe, pneumatic stuff as you say like to open and close valves but they could be electrically driven as well. For ignition maybe not, probably they just open the valves and let the fuel start moving the pumps just using gravity but I'm not really sure. I really need to get up to speed with Starship operations, I wish I had more time for these things.

cheapchips said:
* 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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But I don't think they'll help much with that maneuver, right? Even if they move to hot gas RCS do they have enough thrust to make any difference? I thought that maneuver was handled mainly by the aerodynamic surfaces and the engine's TVC.
 
jayco said:
But I don't think they'll help much with that maneuver, right? Even if they move to hot gas RCS do they have enough thrust to make any difference? I thought that maneuver was handled mainly by the aerodynamic surfaces and the engine's TVC.
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The hot gas RCS they'd proposed was quite sporty, can't remember the stats. It's designed to keep SS/SH on target for landing in pretty much all weathers. I don't know if it removes the need to use Raptor TVC, but the will have enough oomf to change what the manoeuvre looks like.

The landing thrusters for the HLS Moon Starship are probably just a repurposed hot gas RCS design too.
 
Dec 21, 2020
This reel depicts key events during entry, descent, and landing that will occur when NASA’s Perseverance rover lands on Mars February 18, 2021. In the span of about seven minutes, the spacecraft slows down from about 12,100 mph (19,500 kph) at the top of the Martian atmosphere to about 2 mph (3 kph) at touchdown in an area called Jezero Crater.
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cheapchips said:
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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Going back to helium for SN9.

https://twitter.com/x/status/1344344855237992448
 
SN9 blew up as well xD

This time looked like an engine issue, which is worse than a header tank. Let's see what the investigation says.
 
jayco said:
SN9 blew up as well xD

This time looked like an engine issue, which is worse than a header tank. Let's see what the investigation says.
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Looked like a chunk flew out when they tried to light it. Still, SN10 should be later this month. Third time's the charm and all that.

(and the launch and belly flop went perfectly again, so it's a not doom and gloom by any stretch)
 
cheapchips said:
Looked like a chunk flew out when they tried to light it. Still, SN10 should be later this month. Third time's the charm and all that.

(and the launch and belly flop went perfectly again, so it's a not doom and gloom by any stretch)
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It's going to depend on what was the issue with the engine. Lighting a rocket engine on an horizontal position while free falling is really at the limits of what has been done, if Raptor has issues doing it, I think they will try to solve those issues before crashing more ships. Raptor is one of the most advanced engine ever made, I can see it having issues for a lot of time, given how other engines like the SSME took to refine and make them reliable.
 
jayco said:
It's going to depend on what was the issue with the engine. Lighting a rocket engine on an horizontal position while free falling is really at the limits of what has been done, if Raptor has issues doing it, I think they will try to solve those issues before crashing more ships. Raptor is one of the most advanced engine ever made, I can see it having issues for a lot of time, given how other engines like the SSME took to refine and make them reliable.
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Could do. They certainly has issues during static fires. Two has to be swapped out needing minor repairs. They were pushing relights though.

On the upside, over 50 Raptors manufactured. They're really churning them out. If they've not exceeded the number of RS-25s made, they will have done so about.......now. :)
 
Rare(*) slip-up from Falcon 9 this morning. Watching the video it seems that there was something a bit wrong with the re-entry burn and the booster went for an early bath.

(*) What world do we live in where it's a "surprise" that a company failed to land an orbital-class booster on a ship in the ocean??! Odd times people. Odd times.
 
So we now have another rover on a red planet :)
I can't wait when it will start rallying across Martian surface and pooping samples here and there!
When I was watching landing live on YT, I was pleasantly surprised how quickly they got first pictures from the surface after landing. Must be at least ADSL connection now, instead of Dial-up from the years past ;)
 
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