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[New] Space Launch System / Orion Discussion Thread


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6 hours ago, RCgothic said:

If any part of SLS/Orion goes to Mars it'll only be because the vast majority of the work was done by some other boosters. It's completely incapable of constructing any practical mothership in either LEO or at Gateway at any reasonable cost or timescale.

This basically assumes that Falcon Heavy can lift considerably more to LEO than Falcon 9 expendable.  Which in turn assumes that Block 5 was designed with that in mind and provided the support for ~150 ton  loads to orbit (as the infallible wiki claims).  I'm a big fan of Falcon Heavy, and have seen no evidence implying that at all.

But the bigger problem for SLS is that any timescale for NASA planning for Mars would be far more than a decade away.  So any plan to include SLS would have to provide for the thing to survive Shelby's 2022 retirement.  And a commitment to keep the ISS going for well over a decade or provide some other means to assemble such a beast (I'd assume that ISS and the CanadaARM would be invaluable, even with the problematic attitude).

6 hours ago, RCgothic said:

Well they have to pretend Gateway is useful for something.

If you are budgeting for Mars, most of the reasons for the Gateway won't be needed anyway.  They'll just roll up the Gateway pork into the Mars budget.

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Yeah, a buddy and I were chatting yesterday about this, and it's just shocking how overpriced all the SLS stuff is. Not "compared to SpaceX," but compared to the Space Shuttle. My calcs above slopped some stuff up quite a bit for SLS vs Shuttle, and finally I wondered about engine costs, and why they are so high, so I assume much lower RS-25 costs than NASA pays, and I called the EUS a reasonable price at 60M (75% the cost of a Vulcan launch).

The SSMEs should cost at most what they did for Shuttle, but in 2020 dollars, so 200M for that. SRBs should cost 88M, and the core stage 152M. $440M, then whatever an upper stage costs. That's using expensive SSMEs, not engines made less expensive because they don't need reuse.

It's interesting to note that Vulcan uses 2 Be-4 engines, each of which produces a 133% the thrust of RS-25. 

A no SRM Vulcan launch is $82M. Half is launch services, so Vulcan costs $41M. $20.5M is the booster, and the 2 engines cost $13.53M ($6.765M/each).

Now we know what RS-25 SHOULD cost. That's RETAIL, BTW, BO makes money on that. Be-4 is crew rated out of the gate, BTW (Vulcan launches CST-100).

There is zero excuse for the SLS engines to cost more than ~7 million.

So SLS core should certainly cost $268M, with the old stuff scaled to inflation corrected Shuttle prices (which were never "cheap"), and the main engines not being criminally over priced.

What should EUS cost? Well, 5.4m Centaur apparently costs $20.5M, of which presumably 2/3 are the 2 RL-10 engines, so RL-10 are way cheaper than rumor had them, at only the same price as Be-4s. EUS has 4 of those, so EUS has $27M in engines, and that should be 2/3 of the stage cost. EUS should cost $41M per industry norms I overcharged above at $60M.

SLS should therefore cost us $309M.

Launch services would then double that.

Edited by tater
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12 minutes ago, kerbiloid said:

(309-268)/268 = 15%

Have you included tips?

NASA is paying them a 356% tip on each, apparently.

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~$600 million is a lot, but it's totally reasonable for the capability—even with SLS lacking the capability to do the current stated mission alone. heck, at 600M, I'm very much all-in for SLS. Then take the 2.x B$ a year, and launch to the Moon 3-4 times a year. Then we're talking useful capability.

Artemis could launch a lander in one flight. $600M (with launch services) is like 2 FH launches (the FH Gateway launch is $331M). SLS could launch a lunar lander that is just a habitat (no ascent stage). It could be quite large, 8.4m dia, and a few floors high—like a stubby Starship with just enough propellant to get to the surface.

Stop ripping off the taxpayers, and SLS is not so bad.

Orion needs to be replaced, obviously, it's too heavy. If it must be replaced by "not SpaceX," refit CST-100 with a better heat shield, and a BLEO SM.

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2 hours ago, wumpus said:

This basically assumes that Falcon Heavy can lift considerably more to LEO than Falcon 9 expendable.  Which in turn assumes that Block 5 was designed with that in mind and provided the support for ~150 ton  loads to orbit (as the infallible wiki claims).  I'm a big fan of Falcon Heavy, and have seen no evidence implying that at all.

I made no assertion about Falcon Heavy at all in the section you responded to. I said "Some other Booster".

It may indeed be the case that Falcon Heavy can't lift more payload to LEO than Falcon 9. That doesn't change the fact that SLS is never assembling a Mars mission.

A reasonably worthwhile Mars mission will take over a thousand tons to LEO. SLS can't do that on any reasonable cost or timescale. If no other booster exists that can do that then we're not going until one does.

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LEO payload capacity for all launch vehicles is effectively a measure of residual propellant in stage 2 (or stage 3 if it's a 3 stage rocket).

There just are not payloads that use all the fairing volume at the mass levels stated as LEO payload. Starlink fairly well cubes out the fairing, and that's nothing like 64t, it's a quarter of that. Hence the talk on this forum of "naked" FHe, where the only payload under the fairing is a docking port, and S2 gets to orbit with the bulk of the RP-1/LOX remaining.

SLS ends up in LEO with 95t in orbit (whatever it is), of which 27t is actual payload (Orion), the rest is propellants in the upper stage (and the small tank dry mass).

 

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The vast majority of what will be required for a Mars mission is fuel, so residual props isn't necessarily the wrong way to go.

So long as the booster can put up a lot of them on a reasonable timescale for a reasonable cost. That's not SLS by any measure.

It might be FH, or Vulcan, or New Glenn though.

Even if Starship never works reusably as intended, there's no serious reason not to think it'll be an enormously cheap way of putting up a lot of propellant cheaply and often. 

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39 minutes ago, RCgothic said:

The vast majority of what will be required for a Mars mission is fuel, so residual props isn't necessarily the wrong way to go.

So long as the booster can put up a lot of them on a reasonable timescale for a reasonable cost. That's not SLS by any measure.

It might be FH, or Vulcan, or New Glenn though.

Even if Starship never works reusably as intended, there's no serious reason not to think it'll be an enormously cheap way of putting up a lot of propellant cheaply and often. 

Starship has huge capability only after refilling in LEO (at least to move itself anywhere). Though it could deliver an Apollo upper stage sort of mass to LEO (and stage that off for the Moon).

FH/Vulcan/NG are all capable vehicles, with decent payload, and can certainly are more cost effective. The nature of the SLS dev and contracts is bizarre, honestly, and seems designed to maximize cost—as the numbers above clearly show, certain aspects, notably the core stage cost and SRBs are frankly astounding.

DIRECT could have been built, and the same contractors getting paid. It would have leveraged flight heritage, and existing production capability, could have already flown and would have been inexpensive enough to fly multiple times per year for the same annual outlay. Much of the SLS/Orion dev money could have built lunar capabilities, or pushed Mars mission TRLs.

If the people concerned with SLS were more clever than they are, they would push hard to reduce costs to the level it always should have been, and push for increased cadence at much lower cost per flight. Otherwise, SLS gets lapped, and looks stupid and wasteful.

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9 hours ago, tater said:

Starship has huge capability only after refilling in LEO (at least to move itself anywhere). Though it could deliver an Apollo upper stage sort of mass to LEO (and stage that off for the Moon).

Sure, but in this instance I was speaking purely in terms of propellant delivery to LEO.

In every case a means of transferring propellant would be required, but that's a necessary technology for getting to Mars. Full drop tanks would be harder. It'd be easier structurally to put up the tanks as payload and then transfer the residuals from the upper stage.

Edited by RCgothic
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