Why so many engines? I would think you'd use fewer and bigger ones to lessen the chance of failure. It looked like 6 to 10 engines didn't even fire up.
[ - ] germ22 [op] 1 point 2 yearsApr 20, 2023 09:58:29 ago (+1/-0)
IN the stream i was watching they said five or six engines flamed out. I vaguely remember reading somewhere they chose many small engines opposed to few big ones as they are "off the shelf" engines and reduces cost significantly.
It's important to note "cost" is not just a matter of money. An engine has to be designed, built, maintained, etc... this requires time and effort from many specialists who must figure out how to successfully do all that, for that specific engine design, without any room for error.
You cannot just take an existing design, make everything twice as big, and get double the performance while transferring all the hard earned expertise. It just doesn't scale that easily. You would have to start over, nearly from scratch. Back to the drawing board.
You can, however, use two of an existing design. You'll have to figure out how to get them to play nice together... but all the other expertise, and tools, and infrastructure transfers for free. And then you can also use three, four, etc to suit the needs of the specific mission.
The risk that something will not work after you build it is called "Technical Risk." Smaller engines reduce the technical risk. They are also quicker to test and manufacture than larger engines, which is why SpaceX went with the engine size they did.
Raptor engines are not off the shelf. The reason there are so many engines is because a few are expected to fail, so there is redundancy built in. Since this is a test flight, and boom was expected, I wouldn't be suprised if a few of those engines failed on purpose to get telemetry data or to see if the flight software could correct for a borked ship. Apparently it couldn't.
Off the shelf is also implying that they didn't have to engineer the engines from scratch, it takes years in labor to start over with a new design, let alone manufacture it.
I know what off the self means. Raptor engines are specially built for Starship and only Starship by engineerers at SpaceX. There isn't even a shelf to put them on.
What other system? Falcon/Heavy uses the Merlin engine. There is no other rocket that uses the Raptor engines. Only Starship. They were specifically designed for Starship and only Starship.
Falcon 1 and Falcon 9 use Merlin engines, according to SpaceX. Maybe.... Maybe they designed them for starship, And then they used them as off the shelf engines for other projects but they were used on Falcon 1 first.
But what they were originally designed for is irrelevant, they already make them, they are off the shelf, and you don't know what "off the shelf" actually means.
It seems like everything went to plan, everything beyond clearing the tower was an “if,” if it clears the tower and if it gets past max Q then stage separation, etc.
They got what they needed but were hoping for more…
Why is Musk trying to re-discover and re-invent what was already done 50 years ago, except on a large and more complicated scale? Why did he even bother to launch it if he knew there was a 50% chance of failure? I honestly think Musk is being subsidized by the government to waste taxpayers' money.
[ + ] VicariousJambi
[ - ] VicariousJambi 2 points 2 yearsApr 20, 2023 10:17:54 ago (+2/-0)
[ + ] ghetto_shitlord
[ - ] ghetto_shitlord 2 points 2 yearsApr 20, 2023 09:48:57 ago (+2/-0)
[ + ] Master_Foo
[ - ] Master_Foo 2 points 2 yearsApr 20, 2023 10:18:03 ago (+3/-1)
[ + ] germ22
[ - ] germ22 [op] 1 point 2 yearsApr 20, 2023 09:58:29 ago (+1/-0)
I vaguely remember reading somewhere they chose many small engines opposed to few big ones as they are "off the shelf" engines and reduces cost significantly.
[ + ] GloryBeckons
[ - ] GloryBeckons 4 points 2 yearsApr 20, 2023 10:29:02 ago (+4/-0)
You cannot just take an existing design, make everything twice as big, and get double the performance while transferring all the hard earned expertise. It just doesn't scale that easily. You would have to start over, nearly from scratch. Back to the drawing board.
You can, however, use two of an existing design. You'll have to figure out how to get them to play nice together... but all the other expertise, and tools, and infrastructure transfers for free. And then you can also use three, four, etc to suit the needs of the specific mission.
In short, it's more scalable.
[ + ] LiberalsAreMental
[ - ] LiberalsAreMental 2 points 2 yearsApr 20, 2023 10:46:36 ago (+2/-0)
[ + ] ghetto_shitlord
[ - ] ghetto_shitlord 2 points 2 yearsApr 20, 2023 10:15:00 ago (+2/-0)
[ + ] germ22
[ - ] germ22 [op] 3 points 2 yearsApr 20, 2023 10:24:18 ago (+3/-0)
On the one hand redundancy, on the other hand more points of failure.
[ + ] Master_Foo
[ - ] Master_Foo 0 points 2 yearsApr 20, 2023 10:22:48 ago (+1/-1)
The reason there are so many engines is because a few are expected to fail, so there is redundancy built in.
Since this is a test flight, and boom was expected, I wouldn't be suprised if a few of those engines failed on purpose to get telemetry data or to see if the flight software could correct for a borked ship.
Apparently it couldn't.
[ + ] lolxd
[ - ] lolxd 4 points 2 yearsApr 20, 2023 11:28:59 ago (+4/-0)
[ + ] Master_Foo
[ - ] Master_Foo 0 points 2 yearsApr 21, 2023 00:25:46 ago (+0/-0)
[ + ] Master_Foo
[ - ] Master_Foo -3 points 2 yearsApr 20, 2023 14:39:15 ago (+0/-3)
Raptor engines are specially built for Starship and only Starship by engineerers at SpaceX.
There isn't even a shelf to put them on.
[ + ] i_scream_trucks
[ - ] i_scream_trucks 2 points 2 yearsApr 20, 2023 17:59:22 ago (+2/-0)
SpaceX already manufactures them for another launch system. They are the definition of "off the shelf"
They can go into their own facilities and use units already built for a new project that is not what they were originally built for.
[ + ] Master_Foo
[ - ] Master_Foo 0 points 2 yearsApr 21, 2023 00:24:57 ago (+0/-0)
There is no other rocket that uses the Raptor engines. Only Starship. They were specifically designed for Starship and only Starship.
[ + ] i_scream_trucks
[ - ] i_scream_trucks 0 points 2 yearsApr 21, 2023 05:04:47 ago (+0/-0)
What they're designed for is irrelevant, they already build them, and have them available, they're the definition of off the shelf.
[ + ] Master_Foo
[ - ] Master_Foo 0 points 2 yearsApr 21, 2023 14:52:58 ago (+0/-0)
[ + ] lolxd
[ - ] lolxd 0 points 2 yearsApr 20, 2023 23:57:53 ago (+0/-0)
[ + ] Master_Foo
[ - ] Master_Foo 0 points 2 yearsApr 21, 2023 00:23:20 ago (+0/-0)
[ + ] i_scream_trucks
[ - ] i_scream_trucks 0 points 2 yearsApr 21, 2023 05:03:25 ago (+0/-0)*
Falcon 1 and Falcon 9 use Merlin engines, according to SpaceX. Maybe.... Maybe they designed them for starship, And then they used them as off the shelf engines for other projects but they were used on Falcon 1 first.
But what they were originally designed for is irrelevant, they already make them, they are off the shelf, and you don't know what "off the shelf" actually means.
You're absolutely wrong.
[ + ] Deleted
[ - ] deleted 0 points 2 yearsApr 20, 2023 10:29:20 ago (+0/-0)
[ + ] Portmanure
[ - ] Portmanure 1 point 2 yearsApr 20, 2023 10:11:31 ago (+1/-0)
They got what they needed but were hoping for more…
[ + ] germ22
[ - ] germ22 [op] 3 points 2 yearsApr 20, 2023 10:22:37 ago (+3/-0)
[ + ] AngryWhiteKeyboardWarrior
[ - ] AngryWhiteKeyboardWarrior 0 points 2 yearsApr 20, 2023 14:01:52 ago (+0/-0)
[ + ] carnold03
[ - ] carnold03 0 points 2 yearsApr 20, 2023 12:44:50 ago (+0/-0)
[ + ] Lost_In_The_Thinking
[ - ] Lost_In_The_Thinking 0 points 2 yearsApr 20, 2023 12:00:03 ago (+1/-1)
[ + ] PotatoWhisperer2
[ - ] PotatoWhisperer2 0 points 2 yearsApr 20, 2023 18:34:23 ago (+0/-0)
[ + ] Lost_In_The_Thinking
[ - ] Lost_In_The_Thinking 0 points 2 yearsApr 20, 2023 10:06:14 ago (+1/-1)