totm nov 2023 SpaceX Discussion Thread

[darthgently]

49 minutes ago, RCgothic said:

No way did an external fire burn a concentrated hole in an engine nozzle. 

I could see a leak from a damaged nozzle leading to entrained flames that appear like an engine bay fire as it gets worse.

Two engine bell failures is surely an external cause 

What puts small holes in things?  What puts small holes in Russian ISS modules?  The possibilities are endless.

[tater]

FOD in the hot staging ring area?

[RCgothic]

Booster engine missed ignitions:

Flight 7:

Engine to the left of bottom dead centre engine in the ring of 10 on the diagram.

Flight 8:

2 engines to the right of bottom dead centre engine in the ring of 10 on the diagram. Engine that didn't restart was the one immediately to the right of the bottom engine.

 

I believe the diagrams are arranged "belly" side down. So engines at the bottom of the diagram would be earth-facing for a pitch up manoeuvre, if that's the direction it goes.

[Cuky]

Just managed to watch a replay since I fell asleep during countdown yesterday. I must admit it was pretty funny seing real life engineers loosing control of the vehicle in the same way all of us lost it in KSP

[darthgently]

I could see internal debris clearing many sections but getting lodged in the narrow heat exchanger passages in the nozzles also.  Which would create hot spots from decreased cooling.  Maybe?

If the heat exchangers in the vacs are narrower it might favor lodging there also

[Deddly]

If I were riding it, I would feel a lot happier if there were blast shields between each engine.

[RCgothic]

Pretty sure there *are* blast shields between each engine.

That's what the black cylinders around each engine are. 

[darthgently]

55 minutes ago, Deddly said:

If I were riding it, I would feel a lot happier if there were blast shields between each engine.

This is the prototype test version.  Not the riding version.  But the shields are there

[DAL59]

Something interesting this livestream revealed: the progress bars for the methane and oxygen aren't preprogrammed, they are actual telemetry readings. (Because when the ship started spinning, they went up and down from the fuel sloshing around).  

[Minmus Taster]

1 hour ago, DAL59 said:

Something interesting this livestream revealed: the progress bars for the methane and oxygen aren't preprogrammed, they are actual telemetry readings. (Because when the ship started spinning, they went up and down from the fuel sloshing around).  

Very interesting, thought the sensors must have been damaged or something.

[darthgently]

 

20 hours ago, Minmus Taster said:

To my understanding FTS was safed just before the incident, so it wouldn't have destroyed itself.

This is debatable.  Many think the announcer was just reading off a timeline script.  Eventually we may find out

[darthgently]

1 hour ago, DAL59 said:

Something interesting this livestream revealed: the progress bars for the methane and oxygen aren't preprogrammed, they are actual telemetry readings. (Because when the ship started spinning, they went up and down from the fuel sloshing around).  

Previous test flights revealed this also, iirc, didn’t they?  Not as dramatically.  We definitely saw propellant dropping dramatically on Flt 7 via the UI after the leak

12 hours ago, RCgothic said:

If Blue Origin ends up lapping SpaceX, cool. That'd be showing a bit less graditem and a bit more ferociter, and progress is progress no matter who makes it.

I don't think think that's imminent though.

They didn't land, let alone catch, their (smaller) booster, and the second stage they left in orbit caused a high orbit debris event shortly thereafter. At least SpaceX is working out their issues before contributing to Kessler.

That said, V2's record is now 0/2 and Booster again didn't light engines for Boostback, one of which stayed off this time, so there clearly are problems that need to be worked out.

I remain sceptical the problems are localised to the engines, I think it's more likely to be overall system integration and flight dynamics being uncooperative.

That RVac could be solely at fault this time, definitely. It just strikes me as a little weird it looks like a bell extension failure. Bell extensions aren't exactly novel and  SpaceX have heaps of experience with them. There must have been some sort of impact event.

I think the booster engine-outs were on the same side as last time, so those might have been rotation related maybe? Impressive it made it back to a successful catch with multiple missed engine ignitions.

I think it is time to secure Starbase the way the Cape is secured.  A lot of crazies out there.

[GuessingEveryDay]

Well, that's a nice view.

[Lisias]

On 3/7/2025 at 4:45 AM, SunlitZelkova said:

Again, I’m biased here, but I’d argue the Soviet development scheme is perhaps better than the American one. Saturn IB, roughly analogous to Proton, flew perfectly on every flight. Yet it only flew nine times and was thrown away because of its high cost. Meanwhile Proton is still in service. The case is further hit home with crewed spacecraft. Apollo was delicately tested and developed; perfected so that there was never a repeat of Apollo 1. Again it was thrown away, meanwhile Soyuz, which took the lives of four cosmonauts and even more ground personnel during its early years, not only long outlasted Apollo but even outlived the Space Shuttle- the very vehicle that was supposed to make crewed capsules obsolete.

You see, it didn't worked well every time, see N1. Or the Nedelin catastropohe - and, more recently, even the Brazil's VLS-1 V03 in Alcântara (TL;DR: a safety circuit failed previously, so they deactivated it to prevent another mishap as the problem it aimed to prevent was seemed unlikely to happen at that moment. But the lack of that safety caused the booster to accidentally ignite during the preparations for the V03).

As usual, the sweat spot appears to be somewhere in the middle of the two extremes.

Ultimately, the degree of specialization needed nowadays (as well the competition for such specialized work-force) makes the lose of human lives way too costly, what prompts the American way more sustainable on the long run - the Nedelin accident seriously hindered the Soviet program, and the Alcântara accident effectively annihilated the Brazilian one (we just didn't had how to replace the dead specialists).

The problem on NASA nowadays with SLS, IMHO, is the exactly same one that lead to the Space Shuttle disasters, but in the opposite extreme of the spectrum: use of the safety rules to maximize financial achievements instead of technological ones - but instead of minimizing expenditures on safeties, on SLS they maximize the earnings on the same safeties.

 

Edited 18 hours ago by Lisias
Entertaining grammars made slightely less entertaining...

[tater]

 

[Minmus Taster]

11 hours ago, GuessingEveryDay said:

Well, that's a nice view.

Was this leaked? It looks like the sea level raptors are still functioning which they weren't in the given telemetry.

[cubinator]

21 minutes ago, Minmus Taster said:

Was this leaked? It looks like the sea level raptors are still functioning which they weren't in the given telemetry.

Probably the other vacuum engine just behind them.

[AVaughan]

Did they replace any engines between the extended test fire of the ship and the launch? 

An extended test fire at atmospheric pressure, (and within a flame trench which potentially reflects at least some of the acoustic energy back in the general direction of the engines) is probably pretty hard on the engines (and especially the engine bells of the Vac Raptors).  I expect they did a visual inspection afterwards, but they might have missed something.

[AckSed]

The deluge system is supposed to absorb the acoustic energy as well as the heat, but maybe?

"Go-fever" mixing with new and interesting failure modes is... not great.

[Nuke]

14 hours ago, GuessingEveryDay said:

Well, that's a nice view.

seems something is missing. my guess this was taken at an earlier point in the cascade failure progression. gimbels could have been damaged by the engine loss, and then you got slosh which may cause additional engine ruds. do notice the fuel gauges going haywire, fuel level sensors seem to be showing slosh.

Edited 22 hours ago by Nuke

[magnemoe]

14 hours ago, Lisias said:

You see, it didn't worked well every time, see N1. Or the Nedelin catastropohe - and, more recently, even the Brazil's VLS-1 V03 in Alcântara (TL;DR: a safety circuit failed previously, so they deactivated it to prevent another mishap as the problem it aimed to prevent was seemed unlikely to happen at that moment. But the lack of that safety caused the booster to accidentally ignite during the preparations for the V03).

As usual, the sweat spot appears to be somewhere in the middle of the two extremes.

Ultimately, the degree of specialization needed nowadays (as well the competition for such specialized work-force) makes the lose of humans life way too costly, what prompts the American way more sustainable on the long run - the Nedelin accident serisously hindered the Soviet program, and effectively annihilated the Brazilan one (we just didn't had how to replace the dead specialists).

The problem on NASA nowadays with SLS, IMHO, is the exactly same one that lead to the Space Shuttle disasters, but in the opposite extreme of the spectrum: use of the safety rules to maximize financial achievements instead of technological ones - but instead of minimizing expenditures on safeties, on SLS they maximize the earnings on the same safeties.

Agree, and you don't wan't to skimp on human safety but an rocket you will not be able to reuse anyway it makes much more sense to make more of it than gold plate it .
You want to get it to clear the pad or its an obvious fail. 
Now It looks like its an construction fail in SS v2

[camacju]

On 3/6/2025 at 10:44 PM, PakledHostage said:

They have. The Space Shuttle made it to orbit AND BACK on its first flight... 44 years ago.

ah yes the space shuttle

famous for being privately developed and also never killing any astronauts ever

that's the example you choose?

Quote

 SpaceX is in real danger of being lapped by Blue Origin.

I'm looking forward to the ninth flight of New Armstrong later this month!

Edited 20 hours ago by camacju

[.50calBMG]

1 hour ago, camacju said:

I'm looking forward to the ninth flight of New Armstrong later this month!

Ninth flight and fourth landing

[SunlitZelkova]

19 hours ago, Lisias said:

You see, it didn't worked well every time, see N1. Or the Nedelin catastropohe - and, more recently, even the Brazil's VLS-1 V03 in Alcântara (TL;DR: a safety circuit failed previously, so they deactivated it to prevent another mishap as the problem it aimed to prevent was seemed unlikely to happen at that moment. But the lack of that safety caused the booster to accidentally ignite during the preparations for the V03).

As usual, the sweat spot appears to be somewhere in the middle of the two extremes.

Ultimately, the degree of specialization needed nowadays (as well the competition for such specialized work-force) makes the lose of human lives way too costly, what prompts the American way more sustainable on the long run - the Nedelin accident seriously hindered the Soviet program, and the Alcântara accident effectively annihilated the Brazilian one (we just didn't had how to replace the dead specialists).

The problem on NASA nowadays with SLS, IMHO, is the exactly same one that lead to the Space Shuttle disasters, but in the opposite extreme of the spectrum: use of the safety rules to maximize financial achievements instead of technological ones - but instead of minimizing expenditures on safeties, on SLS they maximize the earnings on the same safeties.

 

I think the only reason the N1 didn’t work was because of lack of resources and political support, two things SpaceX now has (the latter in the form of internal backing + HLS contract). The N1 nearly made it to orbit on the 4th flight and probably would have succeeded on the 5th.

But yes, stuff like the Nedelin disaster had no benefit and was pretty easily avoidable.

I was planning to say this in response to the hubbub about lack of regulations and accusations of negligence but I didn’t: SpaceX has no incentive to build an unsafe rocket. They’re a business that doesn’t have a lot of leeway in terms of fatalities or injuries. A carmaker can build something that kills 1,000 people a year and people think it’s normal, but a rocket maker gets one guy killed for the first time in seven years and accusations the company is pure evil go flying.

This is extreme, but even without the FAA (or with a reduced FAA) I would trust SpaceX to at least do some due diligence to make sure people are out of harms way before launching. I also trust them to figure out what went wrong and try to fix it before the next flight.

They’re just not building a minivan where 1,000 out of a million can fail and people won’t care. Space is high profile stuff and they have enormous incentive to improve safety even without having regulators looking over their shoulders all the time.

I think that’s saying a lot considering I’m a person who on the other hand didn’t, and still doesn’t trust SpaceX to do due diligence to protect the environment around Starbase (although as much as I lack that trust I don’t bring it up anymore because I’ve just accepted Starbase is a critical national security facility now and nothing can realistically be done).

[darthgently]

To keep things science-based, it is plausible that SpaceX isn’t failing enough to optimize iterative learning according to experts in learning