Kendra Pierre-Louis: For Scientific American’s Science Quickly, I’m Kendra Pierre-Louis, in for Rachel Feltman. You’re listening to our weekly science news roundup.
Last week NASA’s Artemis II moon mission was delayed by at least a month. After the agency’s so-called wet dress rehearsal revealed hydrogen fuel leaks in the launch vehicle, among other problems.
Here to give us the latest is Scientific American’s breaking news chief, Claire Cameron. Hi, Claire. Thanks for joining us today.
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Claire Cameron: No problem! Glad to be here.
Pierre-Louis: First up, what exactly is Artemis II?
Cameron: Artemis II is a planned mission to send four astronauts in a giant loop around the moon. It’ll take them 10 days, and they’re not actually gonna land on the moon. Instead, they’re going on this big journey around the moon. They’re gonna do some observations and then land back on Earth. And it’s essentially a test flight for future moon missions that will see astronauts actually land on the moon—if all goes to plan.
Pierre-Louis: My understanding is, is that there are a number of potential launch dates for this year, and the most recent one was slated for February. And they did a—what is it—a wet launch, a wet test?
Cameron: So before every launch with crew, certainly, they do what’s called a “wet dress rehearsal.” The “wet” part of it is referring to the fact that they load the rocket up with liquid fuel. So in this case it’s liquid hydrogen and oxygen that they load the rocket up, make sure that it can be fueled properly, and then they drain all the fuel at the end. And they essentially do a simulated launch, so they do the countdown as if they’re about to launch the rocket up into space, but then they stop right before anything gets ignited.
And so this test allows NASA engineers to see if there’s anything wrong with the rocket or the capsule or anything that needs to be sorted out before they actually launch any people on top of the rocket. And in this case they held the wet dress rehearsal on February 2, and they did find issues with both the rocket and the capsule that is going to house the crew on their journey around the moon.
Pierre-Louis: Beginning with the rocket, what was the problem that they found with the rocket?
Cameron: It leaks, so the fuel started leaking out. Specifically, at first, it was the liquid hydrogen that started leaking out. And this was actually a problem with the predecessor to Artemis II, Artemis I—the rocket leaked hydrogen during their tests as well.
Eventually, they managed to get it under enough control to be able to launch that rocket, but it did set back the launch date for it by months as they tried to get rid of the problem. And so I’m sure it’s very frustrating for all the engineers that [roughly] three years later they are dealing with the same problem despite having come up with fixes for it in the past.
Pierre-Louis: Can you talk about the issues with the capsule? And what is the capsule? That’s where the astronauts actually go, right?
Cameron: Yeah, so the capsule sits on top of the rocket; it looks like a sort of little cone. And it will house the four astronauts on their journey. It’s quite spacious, comparatively. So the capsules that go up to the International Space Station, it’s kind of like sitting in a plane seat; you don’t really do very much in there. Whereas the capsule that these astronauts for Artemis II will go up—it’s called the Orion capsule—it is relatively more spacious. It has some space for sleeping, for doing scientific work, for observations, and a bathroom, which is also critical if you’re up in space for 10 days.
And so the problem with the capsule arose when they were trying to close the hatches on the capsule to simulate getting ready for launch and [a valve] malfunctioned. And so [that] required tweaking in order to get [it] to function again.
Pierre-Louis: What are potential new dates for the launch?
Cameron: So right now NASA is targeting March. That will depend on what analysis and what they learn from the results of the wet dress rehearsal. So what they’ll do is that could take days; it could take weeks. We will get another wet dress rehearsal, so they’ll do it again to make sure that everything’s working optimally. With Artemis I it ended up being a monthslong delay from the first wet dress rehearsal to th