KA BOOOOOOOOM

[ponylady]

Congrats to mr musk.

His attempted starship launch proved wernher von braun right.

Whatever you think of that guy (wvb); he chose the right engine concept for large
Rockets, using only a couple of large motors, instead of 30something smaller ones.

The russians already tried that in the 60s with „Nergija“ a couple of times to
Spectacular results, that sadly cost a lot of life on the ground.

I can‘t fathom spacex reasoning for trying this path again.

The saturn V used 5 engines & the shuttle 3. never once was a launch
Lost, due to problems with the engines, once it was deemed save for
Operation. That is almost a 60 year track record.

All the small cluster approach has to show is launch failures.

Which shows one that it is way easier to keep 5 large engines operating in synch, than 30 smaller ones.

[Riddle]

Judging by your post, I would assume you like the KISS method of engineering: Keep It Simple. Was the failure spectacular?

[bound_jenny]

Rather spectacular, yes.

Just about when the booster was to separate from the upper stage, it didn't, and the "flip maneuver" turned the whole kit and kaboodle sideways and boom! Rockets don't like flying sideways. They tend to want a nice straight powered flight along the long axis of the vehicle. Otherwise the stresses break up the rocket and all the fuel and oxidizer mix to make a great big fireball.

SpaceX doesn't really count this as a failure. No one ever considered actually launching an experimental rocket and having it fly for 4 minutes before blowing up a failure. They can analyze what happened, learn from it, and try again until the damn thing works.

It would have been a huge failure had the rocket exploded on the pad. That would have destroyed the pad and set SpaceX back several years.

The russians already tried that in the 60s with „Nergija“ a couple of times to
Spectacular results, that sadly cost a lot of life on the ground.

That was the N1, their moon rocket. It had 30 engines. One of them blew up on the pad on a dry run prior to one launch attempt, killing most of their top engineers. That set the Soviets way back. What really derailed the project was Korolev's untimely death in 1966. Without his genius, they were doomed to failure. Korolev was the Soviets' Von Braun. And Glushko was no Korolev. The program was eventually canceled. All this was completely buried by the Soviet political machine until the fall of the Iron Curtain in 1989 (along with a few other d'oh! moments ).

As for the Saturn V engines, they had development problems too. The huge combustion chambers tended to resonate, and instead of a clean burn it was more like a series of detonations, which could destroy the engines. What fixed that? Some very simple baffles on the injector plate, which helped mix the propellants better for a cleaner, constant burn. Those little baffles were unknown to the Soviets (leaving them completely baffled), and they were stuck with small engines in clusters.

In space exploration, a failure is an opportunity to learn and improve the design. Pick up the pieces, analyze the hell out of them, and fix the problem. If it blows up again, it'll be for another reason. SpaceX is applying this to the letter. It's better to blow up an unmanned rocket than a manned one.

An illuminating book about this process is "Failure Is Not An Option", by Gene Kranz (retired NASA flight director, who directed some of the Apollo missions, including 11 and 13). His former boss, Chris Kraft, once said "If you don't know what to do, don't do anything!" after a rocket failed to ignite (and a few wacky proposals to intervene ).

Best of luck to SpaceX for the next launch.

Jenny.

[Gregovic]

In addition to what Jenny has said already, keep in mind the Soviets at the time were miles ahead of the Americans in terms of small efficient engine design. The choice on the N1 for many small (and efficient) engines over the brute force approach of the US Saturn V S-1C stage wasn't entirely stupid from an engineering standpoint. The biggest problem for the soviets is that the engineers weren't given time to test nor a chance to fail. They knew the problems with the N1 and it's engines, and they knew it wasn't ready to fly, but the (communist) party said launch, so they launched. Multiple times. Ultimately leading to people working on a fueled rocket and the massive kaboom. The US had many many more months if not years of engine tests down to individual components and they solved many issues (the combustion instability was only one of the issues. The turbopump and gas generator development were massive projects by themselves.) IIRC just the gas generator that powered the saturns F1 engines were more powerful by themselves than a single engine NK-15 on the N1 first stage.

This Starship launch proved a lot of things, not the least of which that the orbital launch mount at Boca Chica still needs improving. It's likely at least some of the non-functional engines got taken out by spall from the surface below the launch mount as the massive rocket blasted a giant crater under it. It also seems to have run out of hydraulic fluid from having to compensate for 6 engines out, which is what lead to the flipping/tumbling. I'm surprised they let it's engines burn for as long as they did when it was obvious it was out of control. I don't think it was good proof that the 33 engine approach is wrong or doomed to failure. The N1 was a bad example of that too, given all the other problems with the Soviet space project, and the 5 massive engine approach on S5 had it's fair share of problems too (pogo oscillations, were a big one that they were only getting a handle by the end of the program. It nearly destroyed the first few launches. The F1 engine and S-1C stage just had a lot more development before they even made their first flight. SpaceX is going for a "fail often, fail early" approach, which can be valid and actually be faster.

[Mikel]

Thanks Jen for the book recommendation, just ordered one he should have a lot of interesting things to say about the programs.

Mikel

[ponylady]

Thanks Jen for the book recommendation, just ordered one he should have a lot of interesting things to say about the programs.

Mikel

Here‘s something you don‘t have to buy, but still a spectacular read:

The nasa history series about mercury, gemini & apollo:

https://history.nasa.gov/SP-4201/toc.htm mercury

https://history.nasa.gov/SP-4203/toc.htm Gemini

Sorry, cant find the books about the apollo program & apollo-soyuz project right now.

[ruru67]

Yeah, two destroyed shuttles (a programme that was deeply flawed from the start) and 14 dead astronauts (not to mention deeply slashed budgets) has left NASA a very different organisation from the one that went to the Moon. Honestly, it was just sheer luck that no US astronauts (and as few Soviet ones) were lost in space - both the US and Soviet space programmes had some pretty alarming near-misses, and the technology was ... uh ... not where it is today.

There's no way anyone would approve the Apollo spacecraft for flight today without a lot of changes...

(Although I'd note that Apollo/Saturn had abort modes all the way to orbit and beyond, whereas while the Shuttle SRBs were operating, the abort procedure was basically "hold tight and hope it hangs together.)

[bound_jenny]

while the Shuttle SRBs were operating, the abort procedure was basically "hold tight and hope it hangs together

Indeed. Solid-fuel motors have a major drawback if you're sending anything up there that's not an inanimate object: once they're ignited, there's no way to turn them off like liquid-fuel engines, where one basically "turns off the taps". They'll keep going until all the fuel is spent.

The Artemis program's SLS launcher still uses solid-fuel boosters like the shuttles!

Liquid-fuel engines have a lot more flexibility in that they can be turned on and off at will. But your plumbing must be in impeccable shape, or you have propellants that mix freely outside the combustion chamber and blow up at the drop of a hat.

The shuttle Challenger's loss was caused by a lethal mix: solid-fuel boosters, liquid-fuel main engines, and an imbecilic bureaucracy that wanted to launch at any cost despite warnings from engineers that the temperature was too low for the gaskets between the SRB segments...

Bureaucracy and any kind of rocket fuel don't mix well.

Columbia's loss was caused by a large chunk of insulating foam breaking off of the big fuel tank and gouging some heat shield tiles off the worst possible place - a wing's leading edge, that bears the worst of re-entry heat stresses, along with the nose of the craft. Again, in the accident investigation report, the root of the whole tragedy was the culture at NASA - bureaucrats again. They were resting on the laurels of their past successes so they didn't have to go through all the good engineering practices necessary to make space flight - a dangerous activity to start with - much safer.

The Soviet N1 failure was about the same: bigwigs upstairs ordering the launch come hell or high water. If commissar say we launch, we say da! We launch! (italics pronounced with a thick Russian accent).

By no means should manned space exploration be curtailed until everything is as safe as a child-proof container (though sometimes the children open them up with more ease that adults can... ) Someone has to go out there and push the envelope of what we can do, and find out what we can't do until we devise a way to get around the obstacle.

That's what the spirit of exploration is: taking the risk of going out there, beyond the horizon, to see what's there, and gain knowledge and reap the benefits of that knowledge. If we didn't take to the seas in ships that wouldn't pass muster today, we would still be publishing maps with "here be monsters" written in the big blank space we don't dare go see, because once over the horizon, we can't see home anymore.

The monsters aren't out there, in terra incognita... they down here, their fat arses sitting in their offices pushing pencils and the party line.

Cut the damn umbilical and light this candle. Keep your seat belts on and your hand on the abort switch.

Jenny.

[Mikel]

That's one of my favorite sites! Funny
I remember both shuttle accidents, Raced home to watch the news to find out what happened to the Challenger, then was outside to watch shuttle come in from reentry, when Columbia came apart.

I live in Texas, and had been able to watch that streak go by with an amazing hissing noise a couple of times before.

Can honestly say two of the most depressing days of my life.

I got to see the shuttle Enterprise on the 747 during one of it's return trips from a test flight, got with a few hundred feet before I got caught, LOL

Went and saw, stared at, Discovery in Washington still covered in last reentry blast and man was it impressive, highly recommend that museum if you like aircraft or spacecraft.

Mikel.

[Kinbaku]

... highly recommend that museum if you like aircraft or spacecraft.

Mikel.

Very worthwhile. If you are in Washington, you must take the change to visit it.
I've been there once with special permission to look into the private rooms and talk to the management.

[Gregovic]

Indeed. Solid-fuel motors have a major drawback if you're sending anything up there that's not an inanimate object: once they're ignited, there's no way to turn them off like liquid-fuel engines, where one basically "turns off the taps". They'll keep going until all the fuel is spent.

The Artemis program's SLS launcher still uses solid-fuel boosters like the shuttles!

Theoretically there exists an abort mode for solid fuel motors, explosively detaching the top cap of the motor casing, causing thrust from both ends. Not exactly ideal for a manned vehicle though. As to SLS, while it doesn't just use SRBs "like" they shuttle (They are basically just re-engineered STS SRBs by adding an additional segment and removing the reusability components), since the Orion capsule has a launch escape tower it actually does have a moderately viable abort option all the way from the pad to orbit (it does have to maneuver rather aggressively to avoid any chance of the capsule dropping down through the cloud of burning SRB fragments if the RUD happens early in the launch)

[bound_jenny]

I got to see the shuttle Enterprise on the 747

So did I, 40 years ago when it was on a North American tour that included overflying Montreal:

Photo taken from the south part of Laval, Quebec, by my Dad.

Jenny.

[ruru67]

Yeah, SLS is basically, "build a Saturn class booster from surplus Shuttle parts." It's pretty hard to get excited about what NASA are up to on the heavy lift front.

Much as I dislike Elon and his bullshit, at least SpaceX is doing some interesting stuff. Using methane/LOX is new (everyone else is using Kerosene/LOX, like back in the '50s), and the booster re-usability thing is something everyone is now looking at after SpaceX did it first.

Clustering is something everyone has tried, often with success - from the Soviet R7 line (still flying as Soyuz) through to the 9 motors on the little Electron first stage ... but the Starship scale of clustering hasn't really been tried since the Soviet N1 - four launches, four kabooms. Could the N1 have worked - yeah, probably, if Korolev had been still alive and was able to keep the programme on track ...

[ruru67]

Theoretically there exists an abort mode for solid fuel motors, explosively detaching the top cap of the motor casing ...

Yeah, theoretically. In fact the Shuttle SRBs had range safety charges installed - NASA brass tried to tell the range safety people the thing was going to be so reliable they didn't need them, but the guy in charge of safety took one look at the figures, disagreed, and the charges went in. Remember the pics of the debris cloud from Challenger, with the two smoke trails from the SRBs terminating in explosions? Those was the safety charges destroying the loose SRBs.

But those charges couldn't have been set off without destroying the external tank - after all, the tops of the SRBs were right by the external tank; there's no way you could pop the tops without compromising the rest of the stack.

The Shuttle never had an abort mode once the boosters were lit. That's why they started the SSMEs six seconds before booster ignition - if they didn't have three stable burns (and everything else go) by then, the SSMEs would be shut down and the launch aborted - this happened five times. In fact, early loss of more than one SSME on ascent would likely result in the loss of the orbiter due to lack of landing options - the thing glides like a brick, and ditching would not be survivable. After the Challenger loss, they did introduce bail-out options, i.e. the orbiter would stabilise and the crew would bail out, like they were in a WWII bomber, before the orbiter splashed into the sea. That's about a scary as it sounds.

The four test flights of Columbia had ejection seats for the pilot and co-pilot (the only crew), but the crews actually thought that they were too dangerous to use; with the SRBs still operating they would likely fall through the exhaust plume, and they might survive that, but the parachutes would have burned away ... once the SRBs burned out, they were pretty much too high for ejection to be survivable. The seats got disabled and later taken out when larger crews were introduced.

Really, the only truly viable abort was the abort to orbit - use the remaining engines (and the OMS engines) to boost into a lower orbit and continue from there. They did that once, the only time an engine failed in flight.

Pretty much everything about the Shuttle was asking for trouble. It was a seriously compromised programme.

[Lotharjulz]

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