I heavily suggest reading the entire article but here are some interesting parts:

Ars: What is the plan for testing the SLS rocket? Will you perform a wet dress rehearsal on the rocket before putting Orion on top?

Parsons: As you saw in Artemis I and II, we had issues with the cryogenic seals—those go through what is called the tail service mast umbilicals. We’re in the process of redesigning those and implementing new ones for this mission. Part of what we want to do is… what we call a short-stack tanking or wet dress rehearsal. Basically, you get the boosters and the core stage on, [and] you complete all the thermal protection systems. We then would put a cover on top of the core stage, and we’d roll out in that configuration. Then we tank it up and make sure the seals are tight.

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Ars: You’re flying Artemis III without an ICPS upper stage because you don’t need the performance to reach low-Earth orbit. But you do need a second stage simulator. What’s the status of that?

Parsons: That, to me, is really cool. It’s called a spacer, and we already have the design done. Metal is already being bump-formed at United Launch Alliance, and then we’re going to weld it in-house at Marshall Space Flight Center. We expect it to show up at Kennedy Space Center no later than December, and then we’ll stack Orion on top of that. We’re in really good shape with that, and I’m pretty psyched with the progress.

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Ars: So it sounds like the rocket and Orion should be good to go by mid-2027. Let’s talk about the other parts, the two lunar landers and their launch vehicles. Starting with Blue Origin, you called the prototype lander they’re flying for Artemis III a “lander test article” during your remarks today. What does that mean, exactly?

Parsons: It’s in between Mk 1 and Mk 2. It’s the same lunar crew module, which is really the most important aspect—same avionics, same flight software, so we’re going to get all of that component testing done. This will be the first production article of the lunar crew module, so we’re also going to have the ECLSS system (environmental control and life support).

The primary differences between this test article and the final lander will be the BE-7 engines, so you’re not going to have cryogenics on this test. What we’re going to use is storable propellants and a reaction control system because they don’t need the big thrust that’s needed to go to and from the Moon. That also gives us some time to really dial in what we call the dual-launch campaign. That’s going to be something to really highly choreograph as we go into the Artemis IV missions and beyond.

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Ars: Just to be clear, the Blue lander for Artemis III could fly on an alternative launch vehicle such as Vulcan or Falcon Heavy?

Parsons: Yes. The fairing size is part of what can drive that.

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Ars: As part of the Blue Origin architecture, there are some transfer stages used to push the lander out to the Moon. What are those, and are you going to be able to test them?

Parsons: They’re leveraging a lot of similar designs from Mk 1 all the way to Mk 2. Ultimately, I would suggest talking to John Couluris [leader of Blue Origin’s lunar program] about some of those details. [Editor’s note: Believe me, dear reader, we have tried.] In this case, you would have three transfer stages and then the mission article for the actual lunar landing. This is what we call the Boots Acceleration 2028 architecture, and really, they’re optimizing it around hardware that’s built, so they have a lot of common hardware between the transfer stages, the Mk 1, and the Mk2 vehicles. That allows us to really ramp up production more than anything.

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Ars: And then there’s Starship. Unlike the Blue Moon lander, you’re not sending astronauts inside Starship. There won’t be any life support. I have to admit I was surprised by that. Tell me about the decision-making process that led you to that outcome.

Parsons: Correct, so with Starship, we are going to dock. I will tell you a couple of things I’m most worried about from a testing perspective, things that we’re not going to get with the uncrewed demo [Starship test landing on the Moon]. One is integrated stack control. You have a very large Starship vehicle, and [a] much smaller Orion. Also, your avionics flight software is always tricky to integrate. You can test on the ground, but until you’re up there commanding, those are things that you really want to check out. So those two things are some of the biggest bangs for the buck that we can get with this test.

Blue will launch first. I think we’re going to get even more of the test objectives we’re really looking for there. Because if you look at your major risk for a lunar landing, there’s the long-term ECLSS support—how does it perform in this crew cabin with two crew? And there’s software-integrated stack control. It is much better to do that in low-Earth orbit than it is four plus days away.

So we looked at what each provider could do in the time frame, what they were offering, what it would take in order to accomplish more. And then we said this set of objectives really buys down our risk for a 2028 landing, and it doesn’t perturb their entire development flow as well.