As he should be.

J Fincannon: Isaacman might have sounded calm, but the words were quite blunt and very condemning. They were also words that no one in NASA or any previous administration had the courage to say.

True enough.

” I still don’t understand why we “need” SLS at all (Falcon 9 is human-rated-with-launch-abort already, and Lunar SS can be refueled and checked out in LEO; am I missing anything?),”

Crudely calculated: if you took the loaded weights of the old Apollo Command and Service Module, and the LEM, and built a TLI Booster, you could put them in orbit with F9’s and F Heavies. 2 docks, a TLI boost, dump the TLI booster and you have all the capability to get to the moon and back. Not that I advocate using old tech like that but it kind of shows what could be done with present day operating rockets.

Centaur 5 already has four Vulcan launches worth of flight history and it performed flawlessly on all four. As ULA and NorGrum get their SRB problems sorted out, the Centaur 5 will accumulate quite a bit more flight heritage on Vulcan before being asked to launch crew on the revised Artemis 4 mission in about two years.

Scott Manley pointed this out on X in an especially snarky way, pointing out that Centaur V’s record to date involves four flawless orbital flights, and the Exploration Upper Stage’s record involves . . . [picture inserted of Boeing engineers standing around a large screen with a Power Point.] Manley was immediately dogpiled by the usual crew of SLS defenders. “Boeing has a test article under construction! Here’s photos of it! Why are you so mean?” And, my favorite: “EUS is currently on schedule for Artemis 4 2028 launch!”

Neither Boeing nor the Explorations directorate deserves defenders this passionate.

Yes I have assumed it was just too late to risk a major modification to the mission, one that would delay things even more.

However… if the pre-TLI checkout phase does not go well, the Lunar swing-by can be and should be cancelled… and Orion too! Which cancels SLS.

Elon: “Hold my beer.”

“So is the Artemis 2 mission still to fly around the Moon?”

Yup. Nothing about Artemis II is affected by this announcement.

https://x.com/SenKatieBritt/status/2027516262482379040

Britt is the junior senator from Alabama — she holds Richard Shelby’s old seat, and has taken up his mantle of protecting the NASA footprint in Alabama.

It’s just a post, sure. But it’s fair to think it’s a sign that Isaacman has some major congressional signoff on what he’s trying to do.

Don’t see a reason for it to go around the moon with people. Or really even without people.
The very same tests can be done in low earth orbit. And its safer. Faster and easier to get home.

Problems developed because the goal had been to keep jobs for the majority of the project. No one was truly serious about landing on the Moon or about making a permanent presence there. These were only excuses, lip service, to justify the jobs program that they had turned NASA into.

Now Congress and the president have become serious, and the hardware and methods are inadequate for the job at hand. NASA is announcing new workarounds. Less complex workarounds.
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Milt asked: “If the SLS-Artemis vehicle will no longer be used to transport astronauts to lunar orbit, why not just use Dragon capsules to send the lunar crews into earth orbit and dispense with SLS-Orion entirely? Again, what am I missing here?”

The Earth orbit Isaacman talked about may not be low Earth orbit (LEO). I would not be surprised if the orbit were closer to a geostationary transfer orbit (GTO), which is a highly elliptical orbit (HEO), and requires less delta-v to get to the Moon than LEO would require. The launch vehicle becomes responsible for covering more delta-v so that the Human Landing System vehicle can complete its mission by using less delta-v. Starship has the delta-v to get from a HEO to the Moon and back to HEO, which would make for a nice place for a retanking depot. The Blue Moon landing system may need a slight redesign, such as another tug.

Falcon 9-Dragon and Vulcan-Starliner have what it takes to get to LEO, but maybe not to an appropriate HEO. We will have to see how that all comes out in the wash.
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pzatchok asked: “Why does SLS/Orion need Gateway when Apollo didn’t?”

SLS does not have the lift capability that the Saturn V did, so it cannot lift a command/service module that has the delta-v to get into then out of low lunar orbit. SLS was not designed with a mission, so this whole return to the Moon mission has had to be kluged together with parts we had and a bunch of parts that we still have to make. Modifying SLS was not an option, as a redesign would still take over a decade, as we have learned.

Gateway is to go into a lunar orbit that Orion can reach. This puts less of the delta-v burden on SLS-Orion and more on the Starship or the Blue Moon Human Landing Systems.

“There was no real reason for the project except make work. Get cash to the old companies. Keep politicians on the grift.”

As Robert keeps suggesting but as Reagan said explicitly: government is the problem, not the solution.

Well, to be fair, it is a solution for the companies that were supplying the Space Shuttle’s Space Transportation System, but that solution was at the cost of the all the rest of us, making it a problem for us, in that we had less money for our own use.
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Dick Eagleson wrote: “Thus, beyond Artemis 5, SpaceX will likely get the majority of the subsequent NASA Moon missions because SLS will still be too slow, expensive and expendable and Blue will be production-limited and also more expensive, just not in a class with SLS-Orion in either respect.”

Starship is designed to launch often and at low cost. With it, SpaceX should quickly corner the market on a majority of the lunar launches as well as a majority of the mass lifted into orbit.

Oh, wait. SpaceX did both of those already with Falcon 9.
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Isaacman talked about returning to the 1960s philosophy for a more rapid launch cadence. The philosophies of SpaceX have shown the way. Future projects for both commercial and government space goals and their missions would do well to follow these philosophies. Isaacman is applying one lesson from SpaceX: the best part is no part. He is throwing away or delaying a bunch of Artemis parts, reducing complexity, relaxing or eliminating development time and expense, and encouraging a more rapid mission cadence.

A second lesson is: to learn a little with each mission and not to learn everything all at once. Apollo did that. Gemini did that. Isaacman talked about going from the Artemis II mission to landing on the Moon as being too large of a gap, but I think of it as too large of a leap. Either way, he has advocated for smaller steps to more easily reach the goal.

All: I really appreciate my readers. I am absorbing all your comments and knowledgeable thoughts on what will happen next.

Once I have this digested over the next day or so, I think my brain will click on what it thinks what will really happen. And when it does, I am more often right than wrong on such things.

Isaacman is cancelling EUS because it is hopelessly behind schedule and he aims to make the Artemis program march at double-time from here on out. The fact that serious questions have been raised about EUS build quality will not have been a plus factor either. It is entirely appropriate that Isaacman’s revision of the Artemis program imposes the most pain on Boeing – they’ve earned it.

Switching to an upper stage (Centaur 5) that already has some flight heritage and will have still more by the time it flies with crew aboard eliminates the ghastly joke that was the former plan for Artemis 4.

And, as you have evidently entirely failed to notice, Isaacman is cracking the whip over all Artemis contractors. Far from allowing SpaceX more margin for delay, Isaacman has just made it clear he expects a flight test article of the HLS Starship lander to be in LEO not much over a year from now. The same is true of whatever minimum viable manned lander Blue aims to throw together. Overall, Isaacman aims to speed up SLS core stage production too. Nobody is getting a hall pass here.

And SLS will not remain at Block 1 status. With a twin-engine Centaur 5 upper stage SLS would more properly be called Block 1.1 than Block 1.0.

Given that the new Artemis timeline calls for at least one, and possibly two, manned Moon landings in 2028 I fail to see how any of this is going to allow the PRC to steal a march – or a Long March – on the US. The PRC is still talking 2030 and I have some significant doubts it will be able to make even that date.

Elon will get more money for Starship because the Starship family of vehicle types will soon be able to displace SLS-Orion entirely for pennies on the dollar. Thus, beyond Artemis 5, SpaceX will likely get the majority of the subsequent NASA Moon missions because SLS will still be too slow, expensive and expendable and Blue will be production-limited and also more expensive, just not in a class with SLS-Orion in either respect.

One more thing. The transfer of crew to a lunar lander in LEO is only supposed to be a feature of the revised Artemis 3 mission that now has as its main objective the testing of docking between Orion and one or both of the HLS landers. That will not be SOP for actual lunar landing missions. For those, the Orion will launch from Earth and get out to NRHO on its own where it will meet a waiting lander and do the crew transfer there.

Anent SLS upper stages, the current supply of ULA-built, Delta IV-derived ICPS stages runs out with Artemis 3 – which is now to be an Apollo 9-type LEO test of Orion’s docking capability with one or both of SpaceX’s and Blue Origin’s lunar landers and not a lunar landing mission as formerly planned.

With the Boeing-built Exploration Upper Stage (EUS) now cancelled and the ICPS production line at ULA shut down and repurposed, neither the revised Artemis 4 nor the revised Artemis 5 missions actually have upper stages yet.

The only real choice for this job is a version of the ULA-built Centaur 5, which is the twin-RL-10-engined 2nd stage of Vulcan. Given ULA’s prior experience with ICPS, building a minimally-modified version of Centaur 5 that can mate up with SLS and Orion should be a straightforward exercise for ULA.

And choosing it for use as the new “standard” upper stage of SLS eliminates the most lunatic aspect of NASA’s former Artemis plans, namely flying a crew on the maiden mission of EUS – which was to be Artemis 4 (old-style). Centaur 5 already has four Vulcan launches worth of flight history and it performed flawlessly on all four. As ULA and NorGrum get their SRB problems sorted out, the Centaur 5 will accumulate quite a bit more flight heritage on Vulcan before being asked to launch crew on the revised Artemis 4 mission in about two years.

That’s the good news. The – potential – bad news is that, once Centaur 5 becomes the Standard Cryogenic Propulsion Stage (and we might as well all start calling it the SCPS right now), it can remain in production for at least as long as Vulcan remains viable. So the Old Boy Contractor Club seems likely to lobby for additional SLS-Orion-based lunar missions beyond Artemis 5. If, as seems likely, SpaceX has a Dear Moon-class Starship version ready by 2028 that can swap in for the entire SLS-Orion stack, then we may be spared any SLS-Orion missions beyond the newly-revised Artemis 5, but we should certainly anticipate that SLS backers will try for more.

Gateway certainly seems to be on the bubble. The new – let’s call it SLS Block 1.1 with the new SCPS (Centaur 5) upper stage won’t have enough oomph to get both an Orion capsule and service module as well as a co-manifested Gateway component out to NRHO as was planned for notional SLS Block 1B missions using the late EUS. But Gateway could still be built out, asynchronously from manned Artemis missions, by having its various bits sent NRHO-ward on Falcon Heavies as is the current plan for its initial conjoined PPE-HALO module. That would be far cheaper than co-manifesting Gateway’s modules on SLS-Orion flights and might make it financially feasible to keep Gateway alive for domestic and international political reasons while also taking it entirely out of the critical path for any consequential activity. Heck, Dragon XL might even become an actual thing after all. If we could interest the Indians in building an NRHO-capable Gaganyaan to sub-in for Orion, Gateway might even serve as a sort of mini and part-time ISS-ish destination for mostly non-US astronauts.

Fool me once…

I like you and all, but it is utterly merciless of you to publish a post like this with so many errors and mischaracterizations packed into it that we’ll all be forced to blow out Bob’s comment character limits in any attempt to refute them all.

Richard M: This discussion reveals a very blunt fact about Isaacman’s decision today: He has essentially forced the end of SLS after Artemis-5. NASA has no more upper stages after that flight.

“…..my recollection is that EUS is intended to replace ICPS because the latter had limited availability”

Well, I mean, NASA *could* have procured more than three at any time when ULA’s Delta IV production line was still open; ULA would have been happy to sell them more! (Tory Bruno said as much on X, more than once, when he was asked.) But they never opted to do so.

Too late to do so now, though. But I’m sure ULA will be happy to sell them Centaur V stages instead!

The EUS is supposed to replace the ULA D-IV upper stage currently giving problems, so the optics are such that it will just appear that Jared just smelled a little blood in the water and is back to being Elon’s stooge again after NewSpace called him out for compromising.

The EUS is to be more rugged than any balloon tank, and Stoke may have no interest in building a replacement.

The best option is to complete EUS as planned and have a lander launched atop Falcon Heavy or New Glenn.

By keeping SLS in 1.0 and pushing back a human landing, Jared is buying time for Starship to get its footing…a move which will allow China a jump start.

By limiting SLS to 1.0, he’s trying to make killing it easier. China will land first, and then Elon will try to get more money for Starship.

Sabotage thru policy.

“Why does SLS/Orion need Gateway when Apollo didn’t?”

Oh, my sweet summer child. Do you want the official reasons, or the real reasons?

“….which is why Artemis-3 was delayed until the new mobile launcher was ready.”

Well, actually, the Mobile Launcher 2 was not supposed to be needed, or used, until Artemis IV. Because Artemis IV was supposed to be (until now!) the occasion of the first SLS IB launch. NASA had procured three ICPS stages, to be used for three SLS launches. One has been used for Artemis I; the second is sitting on that stack in the VAB being worked over by ground system crews right now; the third is sitting in storage waiting for Artemis III. That will be the final Block I SLS mission.

The delays with Artemis III, at least as NASA tells it, are due to a) Artemis II having been repeatedly delayed, and b) the mounting fear of delays with Starship HLS and Axiom EVA suits development. That said, Artemis III will also feature the first use of the Orion docking port, and Lockheed has not yet finished that (because of course they haven’t), either….

“the whole upper stage situation has been a joke and an absurdity from day one.”

Completely agreed!

Helpful links:
https://www.nasa.gov/blogs/missions/2025/04/24/nasas-mobile-launcher-2-continues-to-grow/
https://tinyurl.com/3nkhvd6y (that is a NASA link, I had to shorten it)

There was no real reason for the project except make work. Get cash to the old companies. Keep politicians on the grift.

And I love space and rockets. I want to see spinning stations and Moon colonies. But this project wasn’t going to do it. Ever.

Richard M: I am as confused. I was under the impression that for SLS to do its lunar missions, it had to have the upgraded upper stage, which is why Artemis-3 was delayed until the new mobile launcher was ready.

In general, the whole upper stage situation has been a joke and an absurdity from day one. Isaacman dumping is a good thing, for many reasons.

“Ted Cruz may not be fuming as much as you believe. ”

True since all the remaining SLS hardware will get used under the plan as the plan now sits. That can change though.