Here’s what NASA would like to see SpaceX accomplish with Starship this year

SpaceX plans to launch the seventh full-scale test flight of its massive Super Heavy booster and Starship rocket Thursday afternoon. It's the first of what might be a dozen or more demonstration flights this year as SpaceX tries new things with the most powerful rocket ever built. There are many things on SpaceX's Starship to-do list in 2025. They include debuting an upgraded, larger Starship, known as Version 2 or Block 2, on the test flight preparing to launch Thursday. The one-hour launch window opens at 5 pm EST (4 pm CST; 22:00 UTC) at SpaceX's launch base in South Texas. You can watch SpaceX's live webcast of the flight here. SpaceX will again attempt to catch the rocket's Super Heavy booster—more than 20 stories tall and wider than a jumbo jet—back at the launch pad using mechanical arms, or "chopsticks," mounted to the launch tower. Read more about the Starship Block 2 upgrades in our story from last week. You might think of next week's Starship test flight as an apéritif before the entrées to come. Ars recently spoke with Lisa Watson-Morgan, the NASA engineer overseeing the agency's contract with SpaceX to develop a modified version of Starship to land astronauts on the Moon. NASA has contracts with SpaceX worth more than $4 billion to develop and fly two Starship human landing missions under the umbrella of the agency's Artemis program to return humans to the Moon. We are publishing the entire interview with Watson-Morgan below, but first, let's assess what SpaceX might accomplish with Starship this year. There are many things to watch for on this test flight, including the deployment of 10 satellite simulators to test the ship's payload accommodations and the performance of a beefed-up heat shield as the vehicle blazes through the atmosphere for reentry and splashdown in the Indian Ocean. If this all works, SpaceX may try to launch a ship into low-Earth orbit on the eighth flight, expected to launch in the next couple of months. All of the Starship test flights to date have intentionally flown on suborbital trajectories, bringing the ship back toward reentry over the sea northwest of Australia after traveling halfway around the world. Then, there's an even bigger version of Starship called Block 3 that could begin flying before the end of the year. This version of the ship is the one that SpaceX will use to start experimenting with in-orbit refueling, according to Watson-Morgan. In order to test refueling, two Starships will dock together in orbit, allowing one vehicle to transfer super-cold methane and liquid oxygen into the other. Nothing like this on this scale has ever been attempted before. Future Starship missions to the Moon and Mars may require 10 or more tanker missions to gas up in low-Earth orbit. All of these missions will use different versions of the same basic Starship design: a human-rated lunar lander, a propellant depot, and a refueling tanker.

Questions for 2025

Catching Starship back at its launch tower and demonstrating orbital propellant transfer are the two most significant milestones on SpaceX's roadmap for 2025. SpaceX officials have said they aim to fly as many as 25 Starship missions this year, allowing engineers to more rapidly iterate on the vehicle's design. SpaceX is constructing a second launch pad at its Starbase facility near Brownsville, Texas, to help speed up the launch cadence. Can SpaceX achieve this flight rate in 2025? Will faster Starship manufacturing and reusability help the company fly more often? Will SpaceX fly its first ship-to-ship propellant transfer demonstration this year? When will Starship begin launching large batches of new-generation Starlink Internet satellites? Licensing delays at the Federal Aviation Administration have been a thorn in SpaceX's side for the last couple of years. Will those go away under the incoming administration of President-elect Donald Trump, who counts SpaceX founder Elon Musk as a key adviser? And will SpaceX gain a larger role in NASA's Artemis lunar program? The Artemis program's architecture is sure to be reviewed by the Trump administration and the nominee for the agency's next administrator, billionaire businessman and astronaut Jared Isaacman. The very expensive Space Launch System rocket, developed by NASA with Boeing and other traditional aerospace contractors, might be canceled. NASA currently envisions the SLS rocket and Orion spacecraft as the transportation system to ferry astronauts between Earth and the vicinity of the Moon, where crews would meet up with a landing vehicle provided by commercial partners SpaceX and Blue Origin. Watson-Morgan didn't have answers to all of these questions. Many of them are well outside of her purview as Human Landing System program manager, so Ars didn't ask. Instead, Ars discussed technical and schedule concerns with her during the half-hour interview. Here is one part of the discussion, lightly edited for clarity. Ars: What do you hope to see from Flight 7 of Starship? Lisa Watson-Morgan: One of the exciting parts of working with SpaceX are these test flights. They have a really fast turnaround, where they put in different lessons learned. I think you saw many of the flight objectives that they discussed from Flight 6, which was a great success. I think they mentioned different thermal testing experiments that they put on the ship in order to understand the different heating, the different loads on certain areas of the system. All that was really good with each one of those, in addition to how they configure the tiles. Then, from that, there'll be additional tests that they will put on Flight 7, so you kind of get this iterative improvement and learning that we’ll get to see in Flight 7. So Flight 7 is the first Version 2 of their ship set. When I say that, I mean the ship, the booster, all the systems associated with it. So, from that, it's really more just understanding how the system, how the flaps, how all of that interacts and works as they're coming back in. Hopefully we'll get to see some catches, that's always exciting. Ars: How did the in-space Raptor engine relight go on Flight 6 (on November 19)? Lisa Watson-Morgan: Beautifully. And that's something that's really important to us because when we're sitting on the Moon... well, actually, the whole path to the Moon as we are getting ready to land on the Moon, we'll perform a series of maneuvers, and the Raptors will have an environment that is very, very cold. To that, it's going to be important that they're able to relight for landing purposes. So that was a great first step towards that. In addition, after we land, clearly the Raptors will be off, and it will get very cold, and they will have to relight in a cold environment (to get off the Moon). So that's why that step was critical for the Human Landing System and NASA's return to the Moon.

Ars: Which version of the ship is required for the propellant transfer demonstration, and what new features are on that version to enable this test? Lisa Watson-Morgan: We're looking forward to the Version 3, which is what's coming up later on, sometime in ’25, in the near term, because that's what we need for propellant transfer and the cryo fluid work that is also important to us... There are different systems in the V3 set that will help us with cryo fluid management. Obviously, with those, we have to have the couplers and the quick-disconnects in order for the two systems to have the right guidance, navigation, trajectory, all the control systems needed to hold their station-keeping in order to dock with each other, and then perform the fluid transfer. So all the fluid lines and all that's associated with that, those systems, which we have seen in tests and held pieces of when we've been working with them at their site, we'll get to see those actually in action on orbit. Ars: Have there been any ground tests of these systems, whether it’s fluid couplers or docking systems? Can you talk about some of the ground tests that have gone into this development? Lisa Watson-Morgan: Oh, absolutely. We’ve been working with them on ground tests for this past year. We've seen the ground testing and reviewed the data. Our team works with them on what we deem necessary for the various milestones. While the milestone contains proprietary (information), we work closely with them to ensure that it's going to meet the intent, safety-wise as well as technically, of what we're going to need to see. So they've done that. Even more exciting, they have recently shipped some of their docking systems to the Johnson Space Center for testing with the Orion Lockheed Martin docking system, and that's for Artemis III. Clearly, that's how we're going to receive the crew. So those are some exciting tests that we've been doing this past year as well that's not just focused on, say, the booster and the ship. There are a lot of crew systems that are being developed now. We're in work with them on how we're going to effectuate the crew manual control requirements that we have, so it's been a great balance to see what the crew needs, given the size of the ship. That's been a great set of work. We have crew office hours where the crew travels to Hawthorne [SpaceX headquarters in California] and works one-on-one with the different responsible engineers in the different technical disciplines to make sure that they understand not just little words on the paper from a requirement, but actually what this means, and then how systems can be operated. Ars: For the docking system, Orion uses the NASA Docking System, and SpaceX brings its own design to bear on Starship? Lisa Watson-Morgan: This is something that I think the Human Landing System has done exceptionally well. When we wrote our high-level set of requirements, we also wrote it with a bigger picture in mind—looked into the overall standards of how things are typically done, and we just said it has to be compliant with it. So it's a docking standard compliance, and SpaceX clearly meets that. They certainly do have the Dragon heritage, of course, with the International Space Station. So, because of that, we have high confidence that they're all going to work very well. Still, it's important to go ahead and perform the ground testing and get as much of that out of the way as we can.

Ars: How far along is the development and design of the layout of the crew compartment at the top of Starship? Is it far along, or is it still in the conceptual phase? What can you say about that? Lisa Watson-Morgan: It’s much further along there. We’ve had our environmental control and life support systems, whether it's carbon dioxide monitoring fans to make sure the air is circulating properly. We’ve been in a lot of work with SpaceX on the temperature. It’s... a large area (for the crew). The seats, making sure that the crew seats and the loads on that are appropriate. For all of that work, as the analysis work has been performed, the NASA team is reviewing it. They had a mock-up, actually, of some of their life support systems even as far back as eight-plus months ago. So there's been a lot of progress on that. Ars: Is SpaceX planning to use a touchscreen design for crew displays and controls, like they do with the Dragon spacecraft? Lisa Watson-Morgan: We’re in talks about that, about what would be the best approach for the crew for the dynamic environment of landing. Ars: I can imagine it is a pretty dynamic environment with those Raptor engines firing. It’s almost like a launch in reverse. Lisa Watson-Morgan: Right. Those are some of the topics that get discussed in the crew office hours. That's why it's good to have the crew interacting directly, in addition to the different discipline leads, whether it's structural, mechanical, propulsion, to have all those folks talking guidance and having control to say, "OK, well, when the system does this, here's the mode we expect to see. Here's the impact on the crew. And is this condition, or is the option space that we have on the table, appropriate for the next step, with respect to the displays." Ars: One of the big things SpaceX needs to prove out before going to the Moon with Starship is in-orbit propellant transfer. When do you see the ship-to-ship demonstration occurring? Lisa Watson-Morgan: I see it occurring in ’25. Ars: Anything more specific about the schedule for that? Lisa Watson-Morgan: That'd be a question for SpaceX because they do have a number of flights that they're performing commercially, for their maturity. We get the benefit of that. It's actually a great partnership. I'll tell you, it's really good working with them on this, but they'd have to answer that question. I do foresee it happening in ’25. Ars: What things do you need to see SpaceX accomplish before they're ready for the refueling demo? I'm thinking of things like the second launch tower, potentially. Do they need to demonstrate a ship catch or anything like that before going for orbital refueling? Lisa Watson-Morgan: I would say none of that's required. You just kind of get down to, what are the basics? What are the basics that you need? So you need to be able to launch rapidly off the same pad, even. They've shown they can launch and catch within a matter of minutes. So that is good confidence there. The catching is part of their reuse strategy, which is more of their commercial approach, and not a NASA requirement. NASA reaps the benefit of it by good pricing as a result of their commercial model, but it is not a requirement that we have. So they could theoretically use the same pad to perform the propellant transfer and the long-duration flight, because all it requires is two launches, really, within a specified time period to where the two systems can meet in a planned trajectory or orbit to do the propellant transfer. So they could launch the first one, and then within a week or two or three, depending on what the concept of operations was that we thought we could achieve at that time, and then have the propellant transfer demo occur that way. So you don't necessarily need two pads, but you do need more thermal characterization of the ship. I would say that is one of the areas (we need to see data on), and that is one of the reasons, I think, why they're working so diligently on that. Ars: You mentioned the long-duration flight demonstration. What does that entail? Lisa Watson-Morgan: The simple objectives are to launch two different tankers or Starships. The Starship will eventually be a crewed system. Clearly, the ones that we're talking about for the propellant transfer are not. It’s just to have the booster and Starship system launch, and within a few weeks, have another one launch, and have them rendezvous. They need to be able to find each other with their sensors. They need to be able to come close, very, very close, and they need to be able to dock together, connect, do the quick connect, and make sure they are able, then, to flow propellant and LOX (liquid oxygen) to another system. Then, we need to be able to measure the quantity of how much has gone over. And from that, then they need to safely undock and dispose. Ars: So the long-duration flight demonstration is just part of what SpaceX needs to do in order to be ready for the propellant transfer demonstration? Lisa Watson-Morgan: We call it long duration just because it's not a 45-minute or an hour flight. Long duration, obviously, that's a relative statement, but it's a system that can stay up long enough to be able to find another Starship and perform those maneuvers and flow of fuel and LOX. Ars: How much propellant will you transfer with this demonstration, and do you think you’ll get all the data you need in one demonstration, or will SpaceX need to try this several times? Lisa Watson-Morgan: That’s something you can ask SpaceX (about how much propellant will be transferred). Clearly, I know, but there’s some sensitivity there. You’ve seen our requirements in our initial solicitation. We have thresholds and goals, meaning we want you to at least do this, but more is better, and that's typically how we work almost everything. Working with commercial industry in these fixed-price contracts has worked exceptionally well, because when you have providers that are also wanting to explore commercially or trying to make a commercial system, they are interested in pushing more than what we would typically ask for, and so often we get that for an incredibly fair price.