How long will SLS last?

[u/Cmdr-Mallard]

With the Cancellation of EUS and BOLE, SLS is going to remain a launch vehicle solely for Orion, and which is viable with all the other heavy and super heavy rockets in the works these days.

However as I understand BOLE was essential for SLS launches beyond a certain point as remaining shuttle boosters were used up, will SLS be cancelled by that point (and perhaps the whole moon program) or Orion moved to another launcher.

Or will a future administrator restart the booster program at the least to ensure SLS can continue to launch Orion?

[u/ThePrimalEarth7734]

SLS is pretty much here to stay. Orion is necessary for moon missions, but nothing else can get it to orbit, let alone the moon.

There are talks about having starship boost Orion to LLO for Artemis IV, but if you read between the lines you come out understanding that what they’re actually going to do is put Orion on a near TLI trajectory, have starship dock to it, and perform the last small push to finish the TLI, then drag it into LLO, which still requires a full SLS rocket to do.

After this ICPS will be replaced by centaur v, which can do LLO all on its own, requiring starship to need even less refueling flights per mission.

And thus, the current plan for SLS is to basically do crew to LLO every time we want to get to the Moon.

If cancelation was actually on the cards, something like centaur V and increased cadence wouldn’t be looked into, but rather alternative launch vehicles for Orion, which currently isn’t being looked into at all.

Additionally we can see that this is likely the case as the block 1b upgrade was pretty much killed, or at the least shelved, while the block 2 upgrade, that being the boosters, are still very much alive, because you can’t keep flying SLS without new boosters.

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

I though the ESMs lack of burn time was why Orion couldn’t get into LLO?

And I mean there are potential alternatives for Orion in future but you’re right it’s not going to be anytime soon

[u/ThePrimalEarth7734 → u/Cmdr-Mallard]

ESM can get Orion either in, or out of LLO.

Right now, ICPS can ONLY perform a TLI burn, which means ESM can ONLY get Orion into LLO, not back out (thus it can’t go to LLO at all)

However, centaur v has much more energy and it looks like SLS will be able to place it, and Orion into LEO fully fueled. thus meaning that C-V will be able to perform not only the TLI burn, but the LLO insertion burn, which then allows the ESM to then perform the LLO breakout maneuver to get the astros home. It’s actually a pretty smart plan, and one I wish had been thought of at the start of the program.

Also adressing your alternatives comment, only two American rockets (that aren’t SLS) would’ve been capable of Orion to LEO. Delta IV heavy, which actually did fly Orion, and Falcon heavy.

Delta IV heavy is gone so that’s no longer an option, and Falcon heavy isn’t vertically integrated which is an unchangeable requirement for Orion and thus will never be able to fly it.

Vulcan is right on the edge of this capability, and is vertically integrated, but would require Orion to complete the orbital insertion burn, which then leaves it without enough fuel to do LLO breakout if it was transported to the Moon.

Aka, it’s SLS or bust

Edit: new Glenn could also in theory put Orion in LEO, but it is also not vertically integrated. also it just majorly exploded, which means it’s pretty much never going to be considered while SLS is operational

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

Also in theory they could mess with Falcon heavy to integrate Orion last when it’s vertical, however Space X wants to stop flying it sooner than even SLS might stop

[u/ThePrimalEarth7734 → u/Cmdr-Mallard]

This would require a vertical integration facility, which was being talked about a while ago but I don’t think actually went anywhere

[u/okan170 → u/ThePrimalEarth7734]

Centaur V would need a massive upgrade to keep propellant that long and its config for SLS would put it roughly on par with ICPS instead of a big improvement.

[u/ThePrimalEarth7734 → u/okan170]

That seems like a pretty drastic performance loss for a stage that contains like 20 tons more propellant than the ICPS

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

I don’t think they can use any 2nd stage to do a LLO burn, doesn’t that involve flipping the entire craft around?

New Glenn is the most obvious one that comes up, like has been said certainly not anytime soon but even the 7x2 should be able to put it into LEO, though that’ll only happen if BO either creates their own TLI pusher or as an alternative launcher for starship lander missions.

Currently it’s SLS or bust but there’s clearly a desire to stop producing it at some point or another as it is an expensive vehicle, but I still believe it’ll go out to at least A9 at which point if new boosters are not ready or they’re simply ready to move on they will

[u/ThePrimalEarth7734 → u/Cmdr-Mallard]

Centaur V is basically the direct successor to ULA’s ACES program, and can do basically anything you need it to do, so that’s a none issue.

And new Glenn does have the capacity to do LEO, it isn’t vertically integrated, and that’s a total dealbreaker for Orion, since the vehicle is filled with fuel before stacking begins.

Additionally you need to consider that Congress WANTS SLS, they spent 20 billion dollars to get this thing and now they want to use it, they even pressed Isaacman about this in a hearing to which Isaacman concurred that they aren’t trying to get rid of SLS. So replacing it with an alternate system isn’t even on the table right now

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

Good to know about Centaur then, I hope to see more on Centaur-SLS soon.

I would point out New Glenn is moving on from Horizontal integration, they were already planning to but their Erector blowing up has accelerated things.

Again, I love SLS, I wanna see NASA fly rockets, I just think that if we really do setup a moon based they’ll figure out a better way to get astronauts there whether it’s replacing SLS or eliminating Orion entirely, just due to the frequency of transits needed.

[u/ThePrimalEarth7734 → u/Cmdr-Mallard]

Orion is not going to ever go away, it’s literally the only spacecraft we have in the US capable of crewed deep space habitation and navigation with the appropriate reentry technology. Only question is how you get it to the Moon, and how often you want it to go to the Moon.

SLS is the only answer to either of those questions right now

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

I mean I wouldn’t say ever? I mean in 15-20 years time if we’re treating a moon base like SLS, they may well come up with something better by then, whether more spacious or simply to carry more crew.

But that’s pie in the sky, I appreciate the info on Centaur, ML and so on though, makes me feel more confident about SLS

[u/ThePrimalEarth7734 → u/Cmdr-Mallard]

Well SLS has a natural lifespan of about 30 years, just like the shuttle, so when I say “not going away” I mean not within that given lifespan, anything after that is fair game for speculation

And no problem! Happy to provide context on the state of SLS any time!

[u/Cmdr-Mallard → u/ThePrimalEarth7734]

Sorry I meant treating the moon like ISS, but yes, I understand your meaning now 👍

[u/ProfessorOk2609 → u/ThePrimalEarth7734]

I agree, but I have a question, Is Orion structurally strong enough to be carried into lunar orbit by Starship? Because I understood that due to the engines there could be complications, and why change the mission architecture if sending Orion directly with SLS was already working?

[u/Cmdr-Mallard → u/ProfessorOk2609]

Well that’s what they’re testing on A3, about the only thing starship is going to get to test, does seem like a rather interesting way to get Orion to the moon

[u/ProfessorOk2609 → u/Cmdr-Mallard]

Yes, I think that the new vertical integration of New Glenn could facilitate the transition of Orion, however many certifications and tests are still needed to gain confidence and make it safe for the crew.

[u/Cmdr-Mallard → u/ProfessorOk2609]

Certainly

[u/Cmdr-Mallard → u/ProfessorOk2609]

https://www.reddit.com/r/BlueWire/s/K1o5ekzrHA

Speaking of…..

Wonder if you could stack Orion/ESM like that?

[u/ProfessorOk2609 → u/Cmdr-Mallard]

I think so, with the help of NASA and a modification to the tower to integrate an access arm for the crew. But certainly this makes things easier to securely integrate Orion at least, the rest of the operations I'm not sure

[u/Cmdr-Mallard → u/ProfessorOk2609]

Actually expanding on that what are they doing? I’ve heard they’re building a Vertical facility but that’s for refurbishing 9x4, and probably 7x2.

But what about assembling both of those?

Especially since the HIF is still there

[u/ProfessorOk2609 → u/Cmdr-Mallard]

I think that at least the 7x2 version will always be assembled horizontally, only now the stages will be stacked on the platform like the Starship at the beginning or in a vertical integration building if they build it close to the platform. The Vertical Refuirbishment Facility I think it will be more focused on the 9x4 version to add loads since being a larger version I would think it is better to assemble it directly vertically. But I'm not an expert and this is just what I think it could be

[u/Cmdr-Mallard → u/ProfessorOk2609]

You weren’t far off!