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[New] Space Launch System / Orion Discussion Thread


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27 minutes ago, RCgothic said:

Article on the RS25 contracts:

Delivery is 4 engines a year.

Cadence never better than 1 flight per year then.

3.5 billions for 24 engines:  146 milllion/engine.

But they say that in 6 years they could go to 8 engines/year

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It's ugly. It's scam-level expensive. It doesn't have the capability to do the obvious mission architectures. It could *never* do the Mars mission for which it was continuously touted during its early design phase. It's a decade behind when it was needed.

It falls very short on my space hardware coolness yardstick.

Stick the one we've nearly built into the KSC rocket park and let us never speak of it again.

Edited by RCgothic
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SLS is cool because it's big, but sadly that doesn't mean that it's useful as a heavy life vehicle. Its in a very awkward size category where it's too small to easily do lunar missions, but too big for current LEO payloads, and it's sustainer architecture doesn't allow it to be easily made reusable. Combined with a total cost higher than many countries GDP just for one launch, and you can see why it isn't very popular.

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Well, I think I speak for most people here in saying that while we also like big rockets, we'd prefer to see humanity spread it's wings amongst the stars, but in order to do that, we need cheap access to space to enable people to see business opportunities off Earth. SLS is almost the antithesis of what we want to see.

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We have SLS for people who like Kerbal rockets, and we also have Starship for people who like cheap rockets, best of all, they will be finished at around the same time!

(Of course I think we need cheap rockets for more long term space projects, but perhaps we can afford a Kerbal rocket for short time use, and Artemis just has a giant cool factor from the different rockets it uses and a lunar station.)

And let's face it, SLS will be built unless the next round of congress (Is that the right word?) decided to cancel Artemis, which will be a big waste of all that hardware.

(Before anyone mentions sunk cost fallacy, at least we get Artemis done if more money is given to finish SLS, while no actual spaceflight progress is made if the congress decides to choose the cheaper option of cancel the project altogether.)

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We've wasted a decade and tens of billions on SLS. Every flight the US purchases from now on could fund ten to twenty falcon heavy flights.

If Starship hits its targets, every SLS flight could fund a thousand Starship flights.

The opportunity cost here is staggering.

 

And frankly at $143m per engine Rocketdyne and Boeing are taking the US taxpayer for a ride.

 

I'm not convinced you need Orion for a moon landing in 2024. If you can develop a lander in that time you can develop a capsule (particularly with a largely common design - Starship.) But even if you do, Falcon Heavy can push Orion to TLI in two launches for less than the cost of two of SLS's core engines.

Edited by RCgothic
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2 hours ago, Space Nerd said:

I always have different opinions than other people, which is giving me a hard time in life, looks like I won't be doing well on this forum either.

Nah, we can agree to disagree (though yeah, I'm firmly in the "not SLS" camp for all the reasons @RCgothic just said).

I make loads of Kerbal craft based on SLS, actually (my other sig link is to SSTU, which is filled with SLS/Orion parts). Course everything is so cheap in KSP that there's no reason for reuse.

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5 minutes ago, Space Nerd said:

Thanks! (Out of likes)

The truth is, I just don't care about cost that much.

But still, no one agrees with me, typical.

Until Starship/Super Heavy was a thing, the only other game in town that had metal bent was FH.

So even just a few years ago, any "alternative" architectures to SLS for heavy lift required FH, which only flew 2 years ago.

So over 2 years ago, SLS was the ONLY huge rocket that was being worked on aside from FH. FH was not yet actually around, and even so, it's skinny, so payloads are limited for many large (payload volume) human spaceflight missions we might imagine. FH cheaper, but different enough that comparing SLS to FH for many uses was not super useful.

It really wasn't until we had multiple HLVs in the works that things really changed. Vulcan as a real thing (with engine select to Be-4), and NG actually progressing (BO building a rocket factory), plus of course SpaceX starting to actually build SS prototypes that these things went from paper rockets to serious competition for SLS in terms of payload mass and volume to orbit. While only SS directly competes (and exceeds) in mass to orbit, price matters, and EOR is a perfectly good replacement architecture to what SLS has to offer.

That's really when defense of SLS became goofy, IMO. You could argue that FH might be useful when it launches in the future, but it's not crew rated. Then it flew multiple times. You could argue the crew rating bit still, and even with crew FH doesn't buy you that much unless they demonstrate Crew Dragon and higher EDL velocities.

The combo of cheap HL vehicles though is the end for SLS, it's a dead man walking IMO.

Vulcan Heavy + FH for payloads of smaller physical size (FH operational, Vulcan certainly on track to fly, ULA is very reliable). Both an order of magnitude cheaper to fly ($30,000/kg to LEO for SLS vs $3700/kg for Vulcan, $2400/kg for FH).

NG is still an unknown, but I bet it flies as predicted, even if it takes a while to get landing down (though they already have some practice with the easier NS profile). Huge payload volumes, and pretty large mass (price competitive with FH, probably, maybe even cheaper).

Then SS/SH. If it was still presentations at IAC, then people could argue it's not real. There's a tank test article on the pad right now that already fired. It's got more testing, and it has a follow on waiting in the wings, and yet another stacking behind that one. SS is real, anyone saying otherwise is clueless. Even minus reuse, SS achieving orbit obviates SLS.

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Agreed. Up until falcon heavy flew, SLS may not have been ideal but it was the only game in town.

Although I'd go a little bit further than @tater and say that SLS has never been capable of the missions asked of it. It can't fly often enough, and it can't lift enough, and it costs too much when it does fly.

By itself it could maybe do gateway or HEO asteroid rendezvous. Those missions are makework for a rocket that can't do better.

A moon landing absolutely required the development of another heavy lift vehicle to support SLS. But as soon as you got that second cheap heavy lift vehicle able to fly often, EOR becomes a thing. And now there are 4 other heavy lift vehicles.

Talk of SLS and Orion going to Mars was always crazy. Just never going to happen.

 

If SLS had gone straight to Block 2 Cargo and cost maybe half as much, (with crew taxi to LEO on commercial crew) I'd credit SLS a continuing role. But Boeing can never hit that price bracket, and competition from other launchers will get SLS cancelled before Block2 can finally appear sometime in the 2030s.

Edited by RCgothic
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Agreed on every point above. SLS is just a 1960s rehash, throwing away an enormously expensive booster every time you fly humans to the Moon. It's using components from the Shuttle that were designed from the outset with reuse in mind, yet not even trying to reuse them.

SLS Block I is barely capable of sending Orion to the Moon with the current Artemis program (Don't get me started on how underpowered Orion is). Block II is a pipe dream, and by the time Block IB is ready it'll already have been obviated by commercial launch vehicles like Starship. I doubt SLS will be cancelled at this point, but I do know that it probably won't take us any farther than the Moon.

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5 minutes ago, RCgothic said:

Although I'd go a little bit further than @tater and say that SLS has never been capable of the missions asked of it. It can't fly often enough, and it can't lift enough, and it costs too much when it does fly.

I was being as kind to SLS as possible. My principal problem with SLS has always been that it was "a rocket to nowhere."

Orion is left over from Constellation, and on top of that got heavier. It never got a better SM, because it has an overpowered SM as long as you stick to Constellation as the profile.That mission architecture was always Earth Orbit Rendezvous. Orion to LEO on smaller rocket, huge rocket (Ares V, SLS precursor that was also a mess) for cargo.

SLS made something Ares V like (though it can actually work, unlike Ares V), but abandoned the very best part of the concept—separating crew from super heavy lift.

As such we are getting a SHLV with only one cargo, a super heavy crew vehicle (that's a nice way of saying "obese" I guess).

So under the best possible scenario where SLS was already flying around the time of the first FH flight we'd have the capability to send crew sorta near the Moon, where they could basically not do anything.

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1 minute ago, Space Nerd said:

That's enough for me, and I just don't like to find that my opinion is different from everyone else.

As tater said earlier, agree to disagree.

Let's just be happy that we are entering what will most likely be the most exciting decade for space exploration since the 1960s.

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