No launch today

[malada]

I know, I know... it's called rocket science for a reason. This stuff is complicated and hard.

But the real problem with the SLS is the rocket wasn't designed to generate thrust - it was designed to generate pork.

At this point they have enough hardware to generate... what, three launches? Then what? If you want to be serious about returning to space in a big way you need to either mass produce disposable engines or semi mass produce reusable rockets.

Damn, bring on the F1-B - the updated version of the classic F1-A engine that launched Apollo to the moon. Hire Elon to make them recoverable and reusable. I'm a child of the 60s and damn it I want my space station and my moon base.

-m

Will settle for a moon telescope base because... damn, the moon is dangerous.

Comments

[siliconshaman]

Artemus was basically designed as 'proof of concept' rocket. Once they're done they turn over the contract to Elon. That's why the design mostly uses hardware they had already, it's how to do a moonshot on the (relatively) cheap.

I very much doubt NASA will be building F1-B's (or any other engines) themselves, and SpaceX's Raptor engines are more capable anyway (not to mention designed from the ground up to be used more than once).

Bugs me though that Artemis is basically throwing away the only engines NASA built to be reusable, and they are historical artifacts FFS! They belong in the museum they took them from!

But, Elon's goal is to build a fleet of a thousand Starships, and they can only make the Earth-Mars trip every two years, so we'll have a huge fleet of ships that make the round trip to the Moon without refuelling just there waiting to be used the rest of the time.

[malada]

I think Rocketdyne was building the F1-B. They cleaned up the design to use more electronic control. Maybe I'm must nostalgic but I believe the Raptor engines are *a lot* more complicated. I'll take a small hit to performance for less complexity. As Scotty said, "The more complex the plumbing the easier it is to gum it up."

-m

[siliconshaman]

The actual quote is "The more they overthink the plumbing, the easier it is to stop up the drain hole"... but yeah, I take your point.

That said the Raptor 2.0 engines are actually far less complicated. They've reworked the entire turbo-pump assembly, reducing the compolant count significantly and removed a lot of bolted together flanges with simple welds. Since they use a full flow, i.e the entire methane/oxygen flow is used to spin up the turbo pumps, rather than subdividing the flow so the fuel and/or oxygen takes two paths to the combustion chamber, it also reduces the complexity of the control valve assembly.

Basically.. no, the Raptor 2 engines are far less complicated than either the F1-A or proposed F1-B engines. Well.. unless they change the F1-B engine design again that is. The same cannot be said of the Raptor 1 engine...but that's why they redesigned it. Apparently Elon also ascribes to Scotty's design philosophy! Or as he puts it, the best compolant is no compolant.

[jayblanc]

The plan was that when they had run out of mothballed RS-25Ds, they would have enough RS-25Fs produced and tested to continue the program. It looks like the 'second hand' SRS engines might have problems, and if those are the same with the mothballed 'new old stock' RS-25Ds they might accelerate to RS-25Fs faster than they expected. In hindsight you can say it was a bad decision to use the stockpile of RS-25Ds, but the fix to that would be to go back to 2008 and start designing a new engine.

All LHOX engines are 'reusable', they have to be because they all need to be tested before a real mission. The ones that are not 'reusable' are the ones that either melted themselves or exploded during testing. The problem is not 'reusable' it's recovering them after launch.

We can currently do that for a rocket designed for an Earth orbit. We have yet to work out how to do that for a rocket designed for a Moon orbit.

[malada]

If the engines get dumped into the ocean to sink to the bottom they aren't reusable. The throw-away culture was okay if the next engine out of the shop was *better* than the last but I think we've got the design basically worked out.

Millions of dollars of hardware destined for a watery grave. It just irritates me.

[jayblanc]

There's three used S-IVB J-2 engine from the Apollo missions that are still intact and theoretically reusable. You could go get them. It's the recovery that is the tricky part of reusable rocket engines.

[dewline]

As it should irritate all of us.