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[LordBaal]

About five kilos
Hehehe

Oh you mean the Elon rocket? I have no idea.

[alway]

If you're suggesting replacing engines, you may have a few misconceptions. The engines are some of the more expensive parts of a rocket, what with needing all kinds of super-alloys and having extremely low production tolerances.

Hi, I'm new to the thread. It seems very relevant to my interests.

This. Engine reuse is the main reason for it. Engine reuse also have precedent, in that it is done on pretty much every mission to space already. SpaceX, a few days before each launch, hoists the rocket up, fuels it, and does a test burn using the engines to ensure none of them explode immediately from manufacturing defects or similar. Rocket engines aren't built to last indefinitely, but of all the SpaceX flights thus far, there has only been a single engine popping; indicating a pretty high tolerance margin. The rocket itself has an absurdly high tolerance margin, as it can complete its mission even after losing multiple engines (in the case where the engine broke, it made it to orbit successfully).

I believe an online guide for building your own liquid fuel rocket engines suggests that even with ordinary materials, you can get a good few hours of burn time out of one.

Edit: Also, the payload was 11 communication satellites for OrbComm.

[nogoodnames]

Edit: Also, the payload was 11 communication satellites for OrbComm.

Building on that, each satellite weighs 172 kg, so 1892 kg in total. And they were sent to a geosynchronous transfer orbit.

[wierd]

The "super alloys" that rocket engine cowlings are made from is usually something like inconel. It's an alloy of iron and copper. very high temperature resistence before mechanical breakdown, very high density, VERY HARD.

You CAN buy machinable blanks made of the stuff, but good luck cutting it with a consumer grade cnc machine. If you suceed in doing so though, a DIY engine made with it should have similar burn life to the big boy's toys.

Protip: You need to machine it slowly, with spring passes, using at least a carbide cutter and good flood cooling. Hard metals like inconel have internal strain in the metal block, and will "spring" as you cut it. Knowing the grain direction helps to predict how it will spring, but cutting slowly/small passes allows the metal to move like that without going out of tolerance while cutting. (if you take big passes, the metal will spring like crazy, and your passes wont line up like you expect they should. This will produce a bad part. Cutting small passes allows it to spring a little each pass, and the next pass removes the strain relief. tricky, but it works.)

Still, just saying-- you CAN get the same materials for DIY. It isnt like there is an exclusive buyer requirement or something. Just be aware of how that material behaves.

Still, I dont expect there will be many problems found in the engine assembly. The parts most likely to have structural fatigue after use are going to be the landing struts and the seams down the main body.

[Shadowlord]

It's not like it would fit in a museum anyways, right?

Spoiler (click to show/hide)

Considering they have a facility down at Cape Canaveral that houses an entire Saturn V rocket, yeah I think they can find somewhere to put it. If they don't totally destroy it doing the analysis.

Spoiler: Kennedy Space Center (click to show/hide)

BTW, if you ever get a chance, you should visit this. It's pretty fucking epic to see in real life.

I'm impressed.

[RedKing]

It's not like it would fit in a museum anyways, right?

Spoiler (click to show/hide)

Considering they have a facility down at Cape Canaveral that houses an entire Saturn V rocket, yeah I think they can find somewhere to put it. If they don't totally destroy it doing the analysis.

Spoiler: Kennedy Space Center (click to show/hide)

BTW, if you ever get a chance, you should visit this. It's pretty fucking epic to see in real life.

I'm impressed.

Spaceships, aircraft carriers and skyscrapers are three of those things that I think people just can't appreciate how big they are until they see them in person. And then you go "Holy shit, people BUILT this? Humanity FUCK YEAHHH"

[redwallzyl]

It's not like it would fit in a museum anyways, right?

Spoiler (click to show/hide)

Considering they have a facility down at Cape Canaveral that houses an entire Saturn V rocket, yeah I think they can find somewhere to put it. If they don't totally destroy it doing the analysis.

Spoiler: Kennedy Space Center (click to show/hide)

BTW, if you ever get a chance, you should visit this. It's pretty fucking epic to see in real life.

I'm impressed.

Spaceships, aircraft carriers and skyscrapers are three of those things that I think people just can't appreciate how big they are until they see them in person. And then you go "Holy shit, people BUILT this? Humanity FUCK YEAHHH"

went there as a kid. it was awesome.

[Amperzand]

I didn't know that existed, and now would very much like to go.

Given the sheer expense of building a Saturn V, I do have to question why that one's just sitting in a museum instead of doing a job.

[TheBiggerFish]

It's retired.  Probably.

[origamiscienceguy]

There's also a Saturn V at the Johnson Space Center in Houston. And you can find a Space Shuttle at the Udvar-Hazy center in Washington DC. (along with other massive planes such as the Enola Gay)

[Amperzand]

Well, the Shuttle and the Silverplate Bomber make perfect sense, since they were retired intact, but a Saturn V, or any super-heavy lifter, tends to be made for a mission, and then thoroughly dismantled in the process of that mission, since they just drop spent stages into the ocean.

[10ebbor10]

I didn't know that existed, and now would very much like to go.

Given the sheer expense of building a Saturn V, I do have to question why that one's just sitting in a museum instead of doing a job.

They're mix and match jobs made from various test stages, and the rockets from the cancelled Apollo 19 and Apollo 20 missions.

[Amperzand]

That would make a great deal more sense.

[Starver]

That would make a great deal more sense.

And cobbling up a static display from spares doesn't need the rigorous post-production testing that a full orbit-capable version needs.

(There's different challenges in its 'unnatural' horizontal storage, especially for tanks that were at least partially built to keep their structural integrity through being filled with fuel or oxidiser.  But as long as bits aren't falling off and hitting the gawping sightseers below they don't need to worry about everything being airtight/liquidtight and dealing with the stresses of cryogenic and/or combustion temperatures and fluctuating G-forces acting upon redistributing lofted masses....)

Full mock-up cowlings and 'empty' engine-pump-blocks look just as good as the real things, even if they'd never have been intended to be part of viable Saturn V.


There's been a number of fictional tales where a 'museum piece' rocket was drawn into service in time of great need (taking some liberties with reality), and at least one (somewhat more distant from the 'hard science' side of fiction) where this was done by individuals who snuck into the museum and pinched it and launched it, without any assistance from the space agency or any of its spin-off engineering units...  Fueled with Handwavium Trinitrate, I suppose.

[sneakey pete]

If you're suggesting replacing engines, you may have a few misconceptions. The engines are some of the more expensive parts of a rocket, what with needing all kinds of super-alloys and having extremely low production tolerances.

Hi, I'm new to the thread. It seems very relevant to my interests.

If you're rocket was going to drop into the sea after 5 minutes of run time, you would design your pumps, chamber, nozzle etc to last for 5 minutes, throw in your factor of safety and away you go.
They may be able to run longer, but then you're running with less of a factor of safety.

Now, its not to say that spacex hasn't already beefed up the design to make them run much longer, but its something to keep in mind, and as said noone has really looked at an old rocket before so all of the assumptions they made about wear etc were made on best guess/design methods, which will be tweaked using the feedback of an actual rocket.
And then you have rockets that have ablative nozzles, though not sure if the spacex ones are similar to that.