Where are we with SLS and Artemis after all the talk?

A week ago, we had the story of Senator Ted Cruz hosting a "save the SLS" meeting in the US Senate chambers last Wednesday, arguing that acting NASA director Sean Duffy and President Trump himself have both argued we need to make Artemis III's mission the last SLS launch because we simply can't afford to use the SLS.  Cruz argues that if we want to return to the moon in time to beat China nothing we can launch without massive and risky new development has as good a chance of getting us to the moon as SLS.  Ergo, if we want to go back to the moon we simply must pay for the SLS.  The counter argument is that with each SLS launch costing $4 Billion or more, we simply can't afford to go back to the moon.

From the beginning, the second Trump administration has sought to cancel the costly, expendable rocket. Some officials wanted to end the rocket immediately,  but eventually the White House decided to push for cancellation after Artemis III. This seemed prudent because it allowed the United States the best possible chance to land humans back on the Moon before China got there, and then transition to a more affordable lunar program as quickly as possible.  

In response, Ted Cruz added money to NASA's budget (via the "One Big Beautiful Bill" ) to ensure that Artemis IV and Artemis V flew on the SLS rocket, with the promise of additional missions.  

It might be surprising that after the release of their budget proposal back in May, calling for the end of the SLS rocket, the White House and NASA have been quiet.  

However, that changed last week, when interim NASA Administrator Sean Duffy addressed the issue on a podcast hosted by one of the agency's public relations officials, Gary Jordan:

Here is my one concern. If Artemis I, Artemis II, and Artemis III are all $4 billion a launch, $4 billion a launch. At $4 billion a launch, you don’t have a Moon program. It just, I don’t think that exists. We have to bring the price down. And so I have to think about and work with members of Congress. What does Artemis IV, V, and VI look like? But to spend that much money in thinking about what we have to do to have a sustained presence, I think becomes very, very challenging.

Duffy went on to say that since the private sector started advancing the launch industry, a company that wants to put a satellite in space can do it for prices that were unimaginable as little as 20 years ago (still the Shuttle era).   

Duffy clearly argues that the SLS rocket is unaffordable and that any lunar program built around it cannot be sustained for more than a few flags-and-footprints missions. Instead, he says, the agency should be taking advantage of commercial alternatives (which are being developed by SpaceX and Blue Origin). 

I think it's not terribly uncommon for two sides that realize neither of them gets anything they want to sit down and see what they can agree about.  In this case, Ted Cruz's bill says NASA must procure and operate the Space Launch System for Artemis IV and V missions, but it doesn't specify the configuration of the vehicle.  

I don't know how many times I've mentioned that SLS has always been designed with an upper stage option called the Exploration Upper Stage, and that in keeping with the rest of the SLS, it has never been built, never been tested, and nothing associated with it has ever come in "on schedule and on budget" - let alone ahead of schedule or under budget.  So in the budget, instead of saying to buy the SLS,  the House Appropriations Bill calls for the space agency to "evaluate alternatives" to the Exploration Upper Stage.  "Evaluate alternatives" is a wide open door to modify the SLS plans.

One of these, as Ars reported last year, is the Centaur V upper stage built by United Launch Alliance, which is already flight-proven.  Another option is a "short" version of the upper stage Blue Origin currently flies on its New Glenn rocket. Sources indicated that Blue has already begun work on a modified version of the stage that could fit within the shroud of the SLS rocket. This smaller version of the stage, like the Centaur V, would allow NASA to continue launching the SLS rocket using the existing launch tower in Florida.  

But wait.  It gets a bit funnier.  

By canceling the Exploration Upper Stage and second launch tower, NASA could save more than $1 billion annually, which could be applied to other aspects of the Artemis program to ensure its success both in the near and longer term. It would give the Trump administration the talking points it wants on making Artemis more affordable and allow Congress to continue flying its beloved SLS rocket for a few more missions.

Finally, it would buy time to see whether SpaceX and Blue Origin can get their Starship and New Glenn rockets flying regularly and whether NASA can bring down the cost of a partly commercialized SLS rocket. At that point, the future of NASA's deep space program, and the rockets it should use, will be clearer.

A posted NASA graphic of SLS versions. The Block 1B Crewed version features the Exploration Upper Stage while the version that launched in November of '22 is the one shown on the left here. 
This was posted here around 8 months before that Artemis 1 mission flew.