Can someone please explain why the SpaceX ITS with it's 42 engine first stage will work when the Soviet N-1 with it's...

Can someone please explain why the SpaceX ITS with it's 42 engine first stage will work when the Soviet N-1 with it's 30 engine first stage failed miserably precisely because it had so many engines to go wrong.

N1 failed because they never tested the plumbing or vibration in the whole engine until they tried to launch it. If they'd done those things, like spacex presumably is, it would have worked

Because you're an edgy contrarian and not an engineer.

Like SpaceX does either.

That happened during a test

1. I guess they can lose a predetermined amount of engines without aborting the mission.
2. They test fire each engine before it goes to final assembly.
3. They have calculated the mean time to failure for each engine.
4. They trust the god of random numbers.

blank check, with munchkns signature on it

Instead on working on a tiny meme fuel engine (methalox) why don't they just build a F-1 copy? Then they'd only need maybe 8 of those for their meme mission.

Methalox is used so that they can manufacture methane from martian CO2.
I think for every one kilogram hydrogen they carry extra they can make 4 kilograms of methane (i think, can't remember the exact ratio.)
The idea is to take fuel to make more fuel.

>why
Quality assurance. And neither the Soviets nor the Russians have been famed for it.

If they'd tested it, it would have worked" is a nonsense statement. IF they'd had a test-stand big enough to fire the whole engine assembly together, they would have identified the problems, though likely losing an assembly test stand each time, and had a chance to correct some of them -- or, alternatively, they might have concluded that having that many engines multiplies the chances of catastrophic failure in such a way that it makes no sense to waste time and money trying to close them all out, and it makes more sense to reduce your variables and build fewer, but more poerful, engines.

>1. I guess they can lose a predetermined amount of engines without aborting the mission.

True of any well-designed rocket once you get past the "we can only mount one engine" phase. Saturn V lost an engine on two of the Apollo flights, but the remaining engines compensated by burning longer. On the other hand, depending on mode of failure, hafing so many engines crammed in together creats a greater liklihood of one engine failing inuch a way as to take out the one crammed next to it, and a chain-reaction happening, plus you introduce many more possible points of failure as you run wires, hoses and pumps all over the place to feed all those engines, PLUS problems with how vibration, heat, etc. of the whole package impacts the individual engines and structures. You can look for that last through static testing the whole stack, whihc the USSR never did on the N-1

>2. They test fire each engine before it goes to final assembly.

Which "they?" iirc, the USSR had to be satisfied with testing a small number of randomly chosen engines due to cost concerns. Whether a for-profit company would be less or more cost-conscious, and to what extent a "we are super-geniuses, dammit!" mindset would impact engine testing remains to be seen.

>3. They have calculated the mean time to failure for each engine.

Interesting, but meaningless. Engines do not fail on schedule, no more than do the hoses that feed them, etc. You multiple all of that and the associated risks as you multiply engines.

>4. They trust the god of random numbers.
The USSR did not -- they knew they were taking a riskm but the had lost the rocket genius, and were losing a race that had huge national prestige connotations. They were playing catch-up, and had to tolerate a lot of risk if they were to have a shot.

>alternatively, they might have concluded that having that many engines multiplies the chances of catastrophic failure

Not an option for SpaceX. SpaceX intends to make space travel reliable and safe. You do not do that by accepting the chance of an engine exploding, that is OldSpace thinking. You do that by developing an engine that is reliable enough not to explode even when 42 are routinely firing at the same time.

The only way to do that is to test, test, test. 42 engines firing at once is a great test indeed.


Another factor is due to reusability. An engine must be small so that several (due to redundancy) of them can be throttled down enough for stage landing. Cannot do that with large engines.

the russians knew this the 30 engines was a last resort because they couldn't solve the combustion instabilities in large chambers like the americans did so why spacex is using 42 engines as their first design i dont know

>you can't throttle down a large engine
[ciatation needed]

>SpaceX intends to make space travel reliable and safe

That's for the first pioneers to another planet, not routine transportation services.

>42 engine
They're not doing ITS with 42 engines anymore, now it's BFR with 31 smaller engines. It's about half the size of the previous concept, and it's still evolving. Since the announcement, they've changed from 2 near-center sea-level engines (usable for landing) on the spaceship to three, for increased landing capacity and reliability through redundancy on landings.

Arguably the most successful design, the Soyuz rocket, lifts off on thrust from 32 nozzles and is highly reliable.

N1 was a severely underfunded Soviet project in the early days of rocketry, which had its main designer die mid-project. At the time of its last flight attempt, less time had passed from the first object put in orbit than has passed now since the founding of SpaceX. They were applying a "test by flying" philosophy, so failures were to be expected. They had barely begun test flights when NASA put men on the moon, winning the space race, so it quickly lost political support, and was cancelled after only the fourth test, though they had been making reasonable progress.

they aren't taking hydrogen to mars.

first mission is going to set up machines to get martian water ice and break it into o2 and hydrogen. that hydrogen will then be combined with martian co2 to make methane and oxygen.

BFR only has 31 S1 engines now instead of 42
FH has 27 engines

It's probably fair to say that if that is too many engines to work with, spacex will know within the next year.

>An engine must be small so that several (due to redundancy) of them can be throttled down enough for stage landing. Cannot do that with large engines.

Could not do it well with the F-1 as designed, that is not a problem inherent in large engines, it was just not a feature they needed.

>ptptpt, as if spacex does testing
>show's pic of explosion during a test

They've been testing them. I think the most recent was last month or the month before? But, this is BFR not ITS

it's not nonsense at all, it's a straightforward statement. if you attempt to do something without verifying that it's going to work, it's probably not. if you do the work to iron out the problems, there's probably a way to do it if you're determined enough

Soyuz has 20 nozzles actually and it's actually 5 engines, the Russians designed single engines with multiple combustion chambers.

>20 nozzles actually
20 of the larger, fixed nozzles, and 12 smaller, pivoting nozzles.

>it's actually 5 engines
It's 32 combustion chambers and nozzles. Counting nozzles or pumps as engines is arbitrary, and since I said "nozzles" you're not correcting anything, just being a dick with your "actually".

Feeding multiple nozzles from a single pump introduces its own complications and per-nozzle failure modes.

No 1 pump = 1 engine because that is all a liquid-propellant rocket basically is, everything else is just fuel supply and exhausts. Furthermore the pump is the main source of failure. By your logic a single gas engine running two propellers is two engines. As you can see in the picture it is clearly a single unit known as the RD 107. It's one engine. You are wrong ackchyually.

It's not that throttling down a big engine is harder than a smaller one. It is that a big engine will produce more thrust, naturally, and throttling down to 20% is harder than throttling to 60%, so if you need just a nudge, you can't do that on a big engine because 60% of a lot is a fuckton, so it's better to have more smaller engines so that you can have 60% of not so much instead.

>everything else is just fuel supply and exhausts
Yeah man, the main combustion chamber is "just exhaust".

>the pump is the main source of failure
N1 flight 1: pogo oscillation (a main combustion chamber issue) tore the plumbing
N1 flight 2: turbopump blew up
N1 flight 3: uncontrolled roll due to unanticipated exhaust dynamics at liftoff and insufficient thrust vectoring capability
N1 flight 4: water hammer effect during planned engine shutdown prior to staging broke the plumbing

Only one of four N1 failures was a turbopump issue. One started in the combustion chamber, and the other started in the fuel supply.

As for SpaceX's failures:
F1: fuel line nut corroded and broke
F1: first stage bumped and damaged second stage during separation
F1: first stage bumped and damaged second stage after separation
F9: engine main combustion chamber blew up
F9: strut holding heliumd tank broke
F9: helium tank carbon composite overwrap ignited in LOX tank

No pump-related failures.

Rockets fail for all kinds of reasons. If the turbopumps were consistently the main source of failure, they'd have spent more effort on them and they wouldn't be.

The mass of what you're landing is the same so you would still have to throttle down your 8 big engines to 60% if you had to throttle down your 42 small engines to 60%

Do you really not understand that you don't have to fire every engine you have, when you want to produce a low thrust?

Throttling to 0 is super easy though.

Water hammer is a pressure surge no? That's a pump issue. As for SpaceX, great their Merlin turbopumps work good but the Raptor pumps will be bigger, more powerful and running on untested meme fuel.

So the extra engines are dead weight on the descent. This is another important point; 8 large engines would be lighter than 42 small ones. Less, tubes, less pumps, less chamber walling.

>Water hammer is a pressure surge no? That's a pump issue.
No, you twit. It was upstream of the turbopumps. It's when you shut a valve against a current. The liquid has to stop abruptly, and it has mass and momentum, so the pressure spikes. The flow was being driven by tank pressurization, not by turbopumps.

>great their Merlin turbopumps work good
Your claim that the pump is the main source of failure is bullshit.

Even Elon has realized his rocket is bullshit.

Everybody knows it's the trickiest part of the rocket.

>the extra engines are dead weight on the descent
I am appalled that anyone could think this is any kind of argument. The excess thrust capacity is the "dead weight on the descent", and there's no avoiding it. There's need for far higher thrust at lift-off than on landing.

>8 large engines would be lighter than 42 small ones
Rocket engines don't scale like that. There's an optimum size for the best thrust:weight, and it's pretty small. This has been thoroughly studied.

>100% speculation
>journalism
Pick one. Faggots who write these articles and the plebs who read them should just fucking die.

I was right, the ITS design is unrealistic and has been abandoned.

Tragedy that Korolev passed when he did. Wonder if the N1 would have been completed and perhaps the TMK mission would have been attempted?

>when the Soviet N-1 with it's 30 engine first stage failed miserably
Because the N1 was produced in the Soviet Union.

Don't be a chimp. ITS was never the final design, it was an illustrative concept of a work in progress.

It wasn't "unrealistic", it just made more sense when they looked at it to build something smaller. They may go bigger again, since he's announced that it doesn't make sense to build the 9-meter stages in their current factory after all. It costs too much to transport it out of the city (they'd have to take traffic lights down, and things like that). They're looking for a property near the water now to build their BFR factory.

The more recent BFR concept was designed around a minimum-scale Raptor engine (they had planned to scale it up from their prototype, but not down), and the maximium stage diameter in their current factory. Now one of those constraints has been abandoned, so the design will likely change some more.

>It costs too much to transport it out of the city (they'd have to take traffic lights down, and things like that).
I can't imagine that is true, they are just a few blocks from the water
Sure you gotta move the lights or power lines but thats not an immense cost.

>Sure you gotta move the lights or power lines but thats not an immense cost.
Millions of dollars, each time they do it, very little freedom or flexibility in their schedule, and no control over whether the rules or costs change in the future. It's not just the physical work, it's getting the city to go along with it.

I can't remember the source (it was Musk or Shotwell), but I think they said it was ~$10 million each time.

they should build the BFR in Texass and launch there. if they want to later launch at the cape. Then they can ship it around the gulf and florida.

>design btfo
>"i-it was just a concept!"

Really
Why can't they just redo the lights/power lines on the route so that its just a one time fix...
Maybe the city wouldn't allow odd placement of stop lights.

there are regulations on traffic device heights. so that people can see them from their car while stopped at the brake line.

They've said that the workers like living in California. It would be hard to retain factory staff if they tell them all they have to move to Texas. Besides, they want to keep the two factories close to each other, for obvious reasons. They can still make all of the smaller components in the current factory, just not fabricate the tanks and assemble the final stages.

Oh there is also a highway crossing to get to the pacific
Maybe thats a big part of the problem.

that was a test u dumb nigger

Because SpaceX has better engineers and technitians than soviet russia.

Musk is often late, but he does deliver.

There is no amount of shitposting that can dim the mad joy I felt when that reused stage touched down. That was fucking awesome.

>N1 flight 2: turbopump blew up
>Only one of four N1 failures was a turbopump issue. One started in the combustion chamber, and the other started in the fuel supply.
Incidentally, this turbopump explosion only caused loss of vehicle because the engine wasn't properly contained and so the shrapnel severed propellant lines, and damaged other components. N1 was supposed to have engine-out capability (it could lift off with nearly a third of its engines off), but for that to work, you need armor between engines so when one blows up, it doesn't destroy anything else.

SpaceX does the containment properly. They've had an engine blow up and continued the flight to orbit.

would SpaseX with Loren Grush

He didn't deliver Red Dragon.

1. engineers are not full of vodka
2. they have time and ressources for tests
3. their thrust ballancing system should actualy work, other than the one of the N-1
4. a single engine failiure would not be critical , the rocket would shutdown the engine on the opposite site and continue flying with 2 engines less, just like Falcon-9 is supposed to do
5. N-1 was forced to be ready before Saturn-V and therefore rushed, resulting in human

I donĀ“t say it will 100% work first time, just that it is more likely than the russian N-1 was...

>The number of engines has no correlation whatsoever with their failure rate
>The N1 was designed with many small engines because the guy who could have gotten new bigger engines designed for it was the same guy who had put korolev in the gulag for soviet backstabbing ladder climbing purposes and korolev understandably wanted absolutely nothing to do with him. The ITS is being designed with numerous small engines on purpose.

>falling for the spaceX meme

Elon musk is the biggest snake oil salesman since Tony Blair sold the Iraq war to the west.

ah yes it's clearly a sham what with all those rockets that they haven't been launching
oh wait

Joke answer: VODKA LOL
Actual answer: the soviets were cutting corners left and right in order to beat the USA to the "finish line"

for example look at everything that went wrong during the first space walk
or look at their commercial supersonic aircraft

Neil, Buzz and that third guy were all told to be prepared for death

there was a speech for the president drafted in case they didnt return

even more actual answer: russians were poorly educated compared to western scientists

>due to cost concerns

The engines powering the N1 had ablative nozzles and could only be fired once. They had to test one engine form every batch and throw it away, it had nothing to do with the cost of testing engines.

No it's actually a problem inherent to rocket engines. You can't throttle them down past a certain point without risking unstable combustion, chugging, flow separation, etc. The only solutions are to build your engine with a nozzle than won't suffer these problems, which usually means adding weight and complexity, or just build a smaller engine and use more of them.

>Water hammer is a pressure surge

Yeah but not caused by the pumps. The hammer came from the scheduled shut down of several engines for G loading reasons, but the sudden reduction in G force made the fuel lines hammer all over the place and caused the failure.

>russians were poorly educated
Very questionable interpretation. The Americans had far, far more money to work with. More materials, more advanced components, more hours of labor at any given skill level. In fact, this was their eventual downfall, as the profiteers and careerists swept in to take advantage of the funding, leading to the cancellation of the moon program for being too expensive and decades of waste and slow progress after Apollo.

Russia, I think, had equal or better geniuses at the top of their space program.

Musk fanboys are so fucking pathetic.
A real man owes up to his failures and nobody actually working at SpaceX at the time considers this anything other than a failure.

Is this why redditors are so pathetic and beta, and why musk fanboys tend to congregate on that site?

>nobody actually working at SpaceX at the time considers this anything other than a failure.
Of course it was a failure, and a costly and unanticipated one, but it wasn't a launch failure, it was a failure in testing. The presence of the payload on top of the rocket was unnecessary and approved by the customer in exchange for a reduced price. The launch insurance didn't pay for it.

>>N1 failed because they never tested the plumbing or vibration in the whole engine until they tried to launch it. If they'd done those things, like spacex presumably is, it would have worked
>Like SpaceX does either.
>[picture of a test gone bad]

That's because it was a dead end. The Mars vehicle was originally going to be like a very big Dragon 2 with side mounted engines, but analysis showed that it would be a better idea to go for bottom mounted engines and belly flop entry. They also didn't get much interest in Red Dragon from organizations that would be making its payloads.

I used to be a musk fan until I realised he's just some dude from California, I figure let him live his lifethe way he wants, while I live my own terms everyone's an individual, no-one has "godlike" status, we're all just mere mortal men if you get down to it.

>russians were poorly educated compared to western scientists
Operation overcast/paperclip helped the USA a lot with that...

musk finds a way to get new shit to market.

That and some of the rocket engines that came out of the Russian plan the American's thought were impossible.

>musk fanboy
I was simply stating the truth.
musk is a fucking cuck faggot who knows nothing, MUH AI DANGER, MUH SIMULATION, MUH MARS.

He's a socially-inept entrepreneur that got reddit to suck his dick.