totm nov 2023 SpaceX Discussion Thread

[Nuke]

1 hour ago, Ultimate Steve said:

I've been pretty bullish on Starship thus far but it is getting a little less justifiable.

If it was an RVac burnthrough as suggested above, this reminds me an awful lot of the second flight of Delta III which did everything right but just got unlucky in a sense, the normally quite reliable RL-10 decided to fail. Obviously RVac has nowhere near the flight history as RL-10, but still, parallels. If this turns out to be  related to the harmonics issue on flight 7, well...

I also find it quite strange that the ship kept going with only 2 RVacs. Maybe there's some non intuitive reason, and I'm not super informed, but at least on the surface level, keeping a compromised ship with no attitude control burning faster into a spiral seems like a bad idea.

im getting a little bit suspicious of this new starship iteration. starting to wonder if it would just be easier to revert to the previous design at least in the aft end. i miss re-entry footage.

[Superpluto126]

Yikes. Booster did amazing today as usual but ship had it rough. Here is hoping 35 does better.

[camacju]

2 hours ago, Exoscientist said:

In any other space company

yeah, why doesn't another space company do it better and show us how it's really done?

oh wait

[PakledHostage]

42 minutes ago, camacju said:

yeah, why doesn't another space company do it better and show us how it's really done?

oh wait

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

[tater]

12 minutes ago, PakledHostage said:

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

Later they decided the chance of LOC/LOM on the first several launches was ~1:9, luckily they didn't die.

The Dragon capsules similarly worked first time.

59 minutes ago, camacju said:

yeah, why doesn't another space company do it better and show us how it's really done?

Exactly. No other company or entity has ever even tried to make anything as ambitious as Starship.

[Lisias]

11 hours ago, PakledHostage said:

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

On the other hand, they took 9 years - from 1972 (program kick start) to 1981 (first fight) and expend 10.9B USD (about 50B nowadays after inflation)

SpaceX started to talk about this vehicle in 2012, but the first prototype (the grass hopper) took off in 2019. From there to nowadays we have 5 years already (plus 7 from the initial talks to grass hoper), but the cost is about 5B USD to this moment - 10 times less expensive.

And had I mentioned they caught a 280 ton, 20 history tall monster of a rocket with two chop sticks? Twice? [Thrice].

Still looks like the way to go, if you ask me.

Edited Friday at 05:51 PM by Lisias
Uhh... Thrice. :)

[tater]

[Exoscientist]

1 hour ago, camacju said:

yeah, why doesn't another space company do it better and show us how it's really done?

oh wait

 SpaceX is in real danger of being lapped by Blue Origin. Blue demonstated the importance of having a top-notch Chief Engiineer in David Limp in reaching orbit on the first flight and rapidly progressing towards landing a large lander on the Moon on an upcoming flight. 

 SpaceX demonstrated the importance of having a top-notch Chief Engineer in not having one. 
 

  Bob Clark

[SunlitZelkova]

1 hour ago, PakledHostage said:

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

38 minutes ago, Lisias said:

On the other hand, they took 9 years - from 1972 (program kick start) to 1981 (first fight) and expend 10.9B USD (about 50B nowadays after inflation)

SpaceX started to talk about this vehicle in 2012, but the first prototype (the grass hopper) took off in 2019. From there to nowadays we have 5 years already (plus 7 from the initial talks to grass hoper), but the cost is about 5B USD to this moment - 10 times less expensive.

And had I mentioned they caught a 280 ton, 20 history tall monster of a rocket with two chop sticks? Twice?

Still looks like the way to go, if you ask me.

I find trying to compare traditional development schemes with SpaceX kinda silly. One can point at Shuttle and say it was fraught with expense and inefficiency for not much, but Saturn V was similarly developed by government contractors and did fly fine on its first flight (albeit with teething issues) just like Shuttle did.

I am obviously biased here but SpaceX’s development scheme isn’t really that new IMO. It is more or less the Soviet scheme, which was influenced by the Soviet space industry’s origins in artillery (as opposed to the American space industry’s origins in aviation).

To put it simply: you build a lot of test articles and fire them off over and over again until it works. Like how you would develop a ballistic missile or artillery piece.

Contrast with the (traditional) American approach: build the most flawless, fine-tuned prototype you can and make sure it works. This is what you do with aircraft because aircraft have test pilots flying them. American aircraft manufacturers developed American spacecraft, and therefore they continued this line of thinking.

When I look at Starship I see Proton. Proton had the most terrible early flight record of perhaps any rocket; the amount of dreams killed and rubles wasted because of it exploding is perhaps unprecedented anywhere else in space exploration history. But it matured and became useful.

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.

SpaceX brings advantages to the table the Soviets didn’t have. They have much more advanced design and analysis tools, and being a private company can focus funding on Starship as needed in a way Soviet designers never could (they had other responsibilities, mainly related to weapons). SpaceX also can fire people who underperform (this was harder for the Soviets for a variety of reasons and contributed to delays and inefficiencies).

Could Starship be built to fly perfectly on its first flight, like the Space Shuttle? Using the traditional American scheme of development? Yes, but it would either have to take massive hits to capability or wind up being so expensive it would be retired in a decade or two.

SpaceX is not trying to develop a Space Shuttle for the 21st century. They are trying to develop a Soyuz, or a Proton for the 21st century. No American rocket developed in the 60s is still flying today. Soviet rockets are. SpaceX is trying to build something that will be economical and useful for the next 60 years, not something that will fly a number of perfect missions I can count on my fingers and then get retired.

[Hotel26]

11 hours ago, Exoscientist said:

In flight explosions on 6 out of 8 test flights. In any other space company questions would be raised of the Chief Engineer. Unfortunately for SpaceX, the Chief Engineer is the owner of the company. 

If the Chief Engineer is the owner of the company, that's all fine then, yes?  Maybe the competition will just, you know, eat his lunch.  If they're not just "all washed up", as it appears.

This is the thing, Bob.  Science is *supposed* to change knowledge, technology and, yes, even supersede the plodding ways of the past.  I know this could be hard for the practitioners in a field to understand that they themselves are, just...  all washed-up; yes?  But this is what scientific revolutions do ... to careers.  Bob.  The world just moves on, as one gets older, you see.  (Speaking from experience, too.)

Oh but yes, "unfair government influence".  (Not so great when it's suddenly "not on your side",  hey??  <snip>)  My opinion is that the FAA has a duty to respond to and serve the public interest.  That includes for space exploration and especially future flights to the Moon, Mars and possibly the asteroid belt.

It has to accommodate it; but not direct it.

SpaceX progress, the utility of Starlink and demonstrated synergy with NASA programs have proven the worth of SpaceX to the world at large.  The FAA could and should investigate upgrading its capability to handle mixed-mode traffic to respond to this progress (as it always has done: think GA/commercial/military comingling). 

The US ought to be glad that the world's premier space program is still based on US soil and if that brings some issues with airspace or wildlife reserves, then that should be considered from every angle -- including that of the much-vaunted 'national security'.

 

Edited Friday at 02:15 PM by Hotel26

[Nuke]

4 hours ago, PakledHostage said:

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

yea but how many people did the shuttle ultimately kill? would rather ships blow up now than later when they carry people.

[RCgothic]

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.

Edited Friday at 11:48 AM by RCgothic

[darthgently]

4 hours ago, Lisias said:

Twice

Ahem, thrice

[Deddly]

Here is your weekly reminder to keep political discussion off this forum, please.

[tater]

2 hours ago, RCgothic said:

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.

Interesting. Maybe true.

2 hours ago, RCgothic said:

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.

The extension on Mvac  is niobium, and really thin, Rvac is a regen bell extension, so more complex—more stuff to fail.

[Exoscientist]

12 hours ago, DAL59 said:

5 out of 8, I don't think IFT-6's controlled, preplanned booster splashdown should count.  

 

https://youtube.com/clip/UgkxxzYSZbpeDTcua39lvmtSoTIhxsVG9IiS

 Actually, I was referring to the 4th flight. A Raptor exploded during the landing burn. The booster then exploded just before ocean touchdown.  In this flight it has been taken as the ocean touchdown causing the explosion. However, it actually occurred just before touchdown. Then strictly speaking you can consider this also as an explosion in flight.

  Bob Clark

[Superpluto126]

looking at the footage, and some other stuff it might be possible to piece together what seems to have happened. 

Near Engine Cutoff a fire began to develop in the engine bay due to unknown causes. This caused burn through on the Nozzle of a RVAC and led to the explosive Detonation of that engine, which took out those Center Raptors. This caused Damage to Attitude control and led to the uncontrolled spin of the vehicle. The Spin leads to fuel slosh, leading to eventual cutoff the engines.

[Minmus Taster]

50 minutes ago, Superpluto126 said:

looking at the footage, and some other stuff it might be possible to piece together what seems to have happened. 

Near Engine Cutoff a fire began to develop in the engine bay due to unknown causes. This caused burn through on the Nozzle of a RVAC and led to the explosive Detonation of that engine, which took out those Center Raptors. This caused Damage to Attitude control and led to the uncontrolled spin of the vehicle. The Spin leads to fuel slosh, leading to eventual cutoff the engines.

Spin was likely caused by the asymmetrical thrust from the surviving vacuum Raptors. The only things that could have compensated for that are the gimbaling sea level Raptors, and they had been destroyed.

[Superpluto126]

1 minute ago, Minmus Taster said:

Spin was likely caused by the asymmetrical thrust from the surviving vacuum Raptors. The only things that could have compensated for that are the gimbaling sea level Raptors, and they had been destroyed.

Mostly what I meant. Attitude control was likely damaged as well as Center Engines led to loss of control. Had that RVAC survived and all 3 outer engines remained running perhaps it could have made it albeit not survived Splashdown, although at that point its unlikely a center engine would fail either.

[TomKerbal]

58 minutes ago, Superpluto126 said:

looking at the footage, and some other stuff it might be possible to piece together what seems to have happened. 

Near Engine Cutoff a fire began to develop in the engine bay due to unknown causes. This caused burn through on the Nozzle of a RVAC and led to the explosive Detonation of that engine, which took out those Center Raptors. This caused Damage to Attitude control and led to the uncontrolled spin of the vehicle. The Spin leads to fuel slosh, leading to eventual cutoff the engines.

You mean the red dot on the RVAC's bell came from a fire on the outside, not the inside? And why does that cause an explosion? And why can't the bell withstand the heat? Red glow may not be bad at all.  I don't understand any of this.  It's all just speculation here.

[Minmus Taster]

6 minutes ago, TomKerbal said:

You mean the red dot on the RVAC's bell came from a fire on the outside, not the inside? And why does that cause an explosion? And why can't the bell withstand the heat? Red glow may not be bad at all.  I don't understand any of this.  It's all just speculation here.

The observed heating was far beyond average for that engine. The bell seemed to deform slightly too.

[zolotiyeruki]

I just saw Scott Manley's short, and it looks like there might be *two* RVac nozzle extensions damaged: (look at 0:25)

 

[magnemoe]

9 hours ago, SunlitZelkova said:

I find trying to compare traditional development schemes with SpaceX kinda silly. One can point at Shuttle and say it was fraught with expense and inefficiency for not much, but Saturn V was similarly developed by government contractors and did fly fine on its first flight (albeit with teething issues) just like Shuttle did.

I am obviously biased here but SpaceX’s development scheme isn’t really that new IMO. It is more or less the Soviet scheme, which was influenced by the Soviet space industry’s origins in artillery (as opposed to the American space industry’s origins in aviation).

To put it simply: you build a lot of test articles and fire them off over and over again until it works. Like how you would develop a ballistic missile or artillery piece.

Contrast with the (traditional) American approach: build the most flawless, fine-tuned prototype you can and make sure it works. This is what you do with aircraft because aircraft have test pilots flying them. American aircraft manufacturers developed American spacecraft, and therefore they continued this line of thinking.

When I look at Starship I see Proton. Proton had the most terrible early flight record of perhaps any rocket; the amount of dreams killed and rubles wasted because of it exploding is perhaps unprecedented anywhere else in space exploration history. But it matured and became useful.

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.

SpaceX brings advantages to the table the Soviets didn’t have. They have much more advanced design and analysis tools, and being a private company can focus funding on Starship as needed in a way Soviet designers never could (they had other responsibilities, mainly related to weapons). SpaceX also can fire people who underperform (this was harder for the Soviets for a variety of reasons and contributed to delays and inefficiencies).

Could Starship be built to fly perfectly on its first flight, like the Space Shuttle? Using the traditional American scheme of development? Yes, but it would either have to take massive hits to capability or wind up being so expensive it would be retired in a decade or two.

SpaceX is not trying to develop a Space Shuttle for the 21st century. They are trying to develop a Soyuz, or a Proton for the 21st century. No American rocket developed in the 60s is still flying today. Soviet rockets are. SpaceX is trying to build something that will be economical and useful for the next 60 years, not something that will fly a number of perfect missions I can count on my fingers and then get retired.

An excellent point of view and i agree with you. 
Now for planes its also the fact that in many cases also build the tools to build the planes. But UAV even high performance ones like like loyal wingman is significantly cheaper and faster to produce even if an 5th generation fighter plane. 
Yes it can simply be that the UAV scene is used to working on smaller and cheaper stuff and brings on this culture then making much more advanced stuff. 
But i would trust people making pretty  low performance planes making an fighter jet even if unmanned but this is a bit off topic. 

Not sure if falcon 9 was an try until it works? Falcon 1 was, and the recovery of falcon 9 was the poster child of this, and that made perfect sense, first stage was waste once separated so lets try to recover it. 
Have an strong feeling an cooperate or governmental institusjon would not understod this as repeated failure is very bad. 
While making  stuff like Juicero, AI pin or the Skull & Bones and Concord video games who all knew would flop so hard. 
Or governmental projects like SLS. who made some sense at the start but not now. 
 

[RCgothic]

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 

[Superpluto126]

1 hour ago, TomKerbal said:

You mean the red dot on the RVAC's bell came from a fire on the outside, not the inside? And why does that cause an explosion? And why can't the bell withstand the heat? Red glow may not be bad at all.  I don't understand any of this.  It's all just speculation here.

The Red Glow was only on one engine and seemed to be off nominal, and a Nozzle is mostly equipped to withstanding heating from the inside rather than out