Ep. 651: Artemis and the Decline of Single Use Rockets (1)
Frasier: Astronomy Cast Episode 651: Artemis and the decline of single-use rockets. Welcome to Astronomy Cast, your weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I'm Frasier Cain. I'm the publisher of Universe Today. I've been a space and astronomy journalist for over 20 years. With me, as always, is Dr. Pamela Gay, a Senior Scientist for the Planetary Science Institute, and the director of CosmoQuest. Hey Pamela! Welcome back!
Dr. Gay: We are here! We are here! And I am here to say that 20 years ago this month, I turned in my PhD's first full, complete draft. My PhD turns 20 in December.
Frasier: Right. Your PhD is – well, it's old enough to drink in Canada, and it would want to.
Dr. Gay: It's true.
Frasier: Yeah. Just not in the US yet. Yeah, so –
Dr. Gay: Right.
Frasier: – we're back! We finished our summer hiatus. I hope you had a great and – you know, I always sort of say, “Oh, we had a relaxing summer,” but neither of us actually relaxed during our summer hiatus. We just don't do livestreams. We do all the other stuff that we had to catch up on.
Dr. Gay: And we both had massive construction going on in different formats.
Frasier: Yeah.
Dr. Gay: Yours I think was more massive, and mine was simply more inconvenient. So, my studio no longer has the ceiling it used to have, it also doesn't have a new ceiling yet. So, that's still –
Frasier: Right.
Dr. Gay: – being worked on.
Frasier: Yeah. Yeah. No, so we finished our shop and studio. And so now, I'm actually recording the new episodes in the new studio. It's still a little hollow-sounding. I need to get a little more sound baffling in here. But it is so great. The internet is still a little slow, but we're gonna be upgrading to a faster internet in probably about a month from now. But apart from that, it's so convenient to be able to just sit down in front of the computer, turn on a couple of switches and livestream, as opposed to being hunched over a computer in the back of a trailer, etc. etc. So, it feels great.
Dr. Gay: Yes.
Frasier: Thank you to everyone at Standing There Construction for helping us build this shop and studio, and get to a new level of productivity. It's kind of surreal, because I'm just able to just use my stuff now, as opposed to –
Dr. Gay: Yes.
Frasier: – be waiting for things to be finished, or staring at a sea container that contains all of my worldly possessions, or carrying water in jugs, or –
Dr. Gay: Yes.
Frasier: It's just like there was so much friction. And now suddenly, all of that friction is gone. And yeah, well obviously, because that was the point. But –
Dr. Gay: Yes.
Frasier: – still, yeah, it feels good. But you have made changes to your studio as well, so –
Dr. Gay: I have heating and cooling. I have not had heating and cooling down here before. And –
Frasier: Oh.
Dr. Gay: – the fact that I could come downstairs, and it was the same blissfully-controlled temperatures on the first floor of our house –
Frasier: Yeah.
Dr. Gay: – was truly glorious.
Frasier: All right. Let's get into season 16! On the day that we're recording this, NASA's Space Launch System is about to blast off. But everyone is expecting it'll be delayed to October. Now, when it does launch, it'll be the most powerful rocket on earth. Well, until Starship blasts off. So, are we about to see the end of single-use rockets, and enter the era of reusable rocketry? Well, are we?
Dr. Gay: No. And that is something that really surprised me. And in researching this show, the first question I had is why isn't SLS reusing any of its parts? One of the things that's deeply confusing to me is the SLS series of rockets is based on using leftover bits of the Space Shuttle Program. And with the Space Shuttle Program, we had this glorious central external tank and its beautiful shade of orange, we had the two solid rocket boosters, we had the engines on the back of the shuttle.
And while that external tank got burned up in the atmosphere every single launch, those solid rocket boosters were pulled out of the ocean and reused, and those engines on the back of the space shuttle, they had a whole bunch of them. And they reused them, recycling them from mission to mission. Well, with the Space Launch System, they took those engines – they literally have 16 RS-25 series engines that have previously flown on the space shuttle – and they're mounting them on that core stage, which they're burning up in the ocean.
Frasier: Yeah.
Dr. Gay: And those solid rocket booster segments, some of which have had parts that have been used 59 different launches, they're dropping them into the ocean just like they did –
Frasier: Mm-hmm.
Dr. Gay: – with the space shuttle, but they're not pulling them back out.
Frasier: Yes.
Dr. Gay: So, yeah.
Frasier: So, it's almost like we're moving away from the concept of reasonable rocketry, and towards more disposable rocketry. And I mean, I think the biggest issue is with the space shuttle, the space shuttle was actually a more powerful rocket. It was capable of launching a heavier payload to space than the Space Launch System.
Dr. Gay: Yeah.
Frasier: But it had to carry the orbiter. And the orbiter was reusable. And so, –
Dr. Gay: Mm-hmm.
Frasier: – most of the weight, the carry weight, went into launching the orbiter, and then the actual amount of payload that the space shuttle could launch was greatly reduced. And so, with the Space Launch System, you've got a return to very heavy payloads, very little reuse.
Dr. Gay: Right. And in looking into this, I did a survey of – so, who is still going to be using disposable rockets, and why? And why with SLS, where they only get four launches with reusable parts, at the end of those four launches, they're back to having to turn on assembly lines, –
Frasier: Yes.
Dr. Gay: – and start building stuff again. And the reason that disposable rockets are disposable is it makes more sense for low-cadence rockets to not have to have and maintain the infrastructure to go grab things out of the ocean to catch them on parachutes. Basically, if you're not launching over and over and over, like SpaceX sometimes has two or three launches in 48 hours, if you're instead looking at having that many launches in a year, you don't wanna pay for all of that reusability.
Frasier: Yeah. They learned a lot with the Shuttle Program. And –
Dr. Gay: Mm-hmm.
Frasier: – going into the Shuttle Program, the idea was let's make everything fully reusable. Let's shift from this disposable rocket reality into the reusable rocket future. Let's reuse the orbiter, let's reuse the main fuel stage, let's reuse the booster rockets, let's reuse every part of this. And the original idea –
Dr. Gay: Yeah.
Frasier: – for the space shuttle was that it was this little – it looked like the space shuttle, and it was attached to a bigger space shuttle. Imagine you put wings on the main fuel tank, –
Dr. Gay: Yeah.
Frasier: – and then it would blast off, and then the main fuel tank would fly back and land at the landing pad, and then the shuttle would go to orbit, and it would come back. And everything would be reused, and it would be beautiful and wonderful. And then, they –
Dr. Gay: Yes.
Frasier: – added more requirements. And in the end, it all didn't work. But they tried to reuse the orbiter, or they reused the orbiter or the engines, the solid rocket boosters. But the reality was the reuse was incredibly expensive, possibly –
Dr. Gay: Yes.
Frasier: – more expensive than making it single use. Especially for say, the solid rocket boosters, which ended up killing one whole crew of the space shuttle.
Dr. Gay: Yeah. And they didn't have the cadence either. So, they had high-cost reuse, and they had a lower cadence, so they're paying for infrastructure that isn't in constant use. And it was a double whammy that in trying to figure out what to do next, first the Ares series that was part of the Constellation Mission was looking at reusability of shuttle parts. And when that mission went away, and they brought in SLS, they were like, “We're not gonna try that reusability except for the capsule.”
Frasier: Yeah. Yeah, I'm gonna log roll here for a second. And that –
Dr. Gay: Okay.
Frasier: – is because I had a chance to interview the United Launch Alliance's CEO Tory Bruno this summer. So, –
Dr. Gay: Oh, wow!
Frasier: – I did no interviews this summer, except I came out of hiatus to interview Tory Bruno, which was fantastic.
Dr. Gay: Worth it!
Frasier: Totally worth it, yeah! And I learned a ton about the industry and his thinking about it. And we're gonna talk about this in a second, but ULA has no response to the Falcon series of rockets. They're reusable rockets from SpaceX. The kind of idea that Blue Origin is working with the New Glenn, the Chinese are working on reusable rocketry. And –
Dr. Gay: Mm-hmm.
Frasier: – in this current phase, ULA doesn't. And their perspective is that actually, the expensive part of a rocket is the engines. If you can reuse those, you've reused most of the cost of the rocket, and you've maintained the maximum amount of lift capability. So, the rush to reusability is in his perspective, in ULA's perspective, not as urgent as other people think that it is.
Dr. Gay: And they are looking at with the next generation RS-25 engines that they're working on developing, they're looking at getting the cost down by combining new technologies like 3D printing, and by not worrying about, “Well, is it going to be able to survive absolutely undamaged from the launch we're about to put it through?” Because –
Frasier: Mm-hmm.
Dr. Gay: – they're not going to reuse it. If you're not looking to reuse, you can cut corners that you can't cut if you want to reuse. So, thinking there's gonna be about a 30 percent cost savings, and just creating new ones with their new design over the cost of making them originally for the space shuttle. And this idea of, “We're just gonna let things not get reused,” it's something that we've seen over and over throughout time.
We're really used to this with – there's the Atlas V series. And again, it doesn't have a high cadence. Last year, it had nine launches with its peak. It usually launches four to five times. So, we see already with this series – which admittedly, is running into problems because it has parts from the Ukraine and Russia.
Frasier: Right, yeah. Yeah. Supply chain issues.
Dr. Gay: Supply chain issues. A whole new version of supply chain issues. Yeah. Yeah. It has a geopolitically fraught engine and –
Frasier: Yeah.
Dr. Gay: – tank system. Yeah. But with that cadence, they've been able to have a completely disposable, lower-cost rocket for years. We're seeing something very similar with the Delta IV Heavy, it only has three launches left. Which is sad. But –
Frasier: Mm-hmm.
Dr. Gay: – the Ariane 5 is still there. We currently have an image of the one that carried the JTBOST up into orbit onscreen.
Frasier: But it's getting sunsetted as well to the Ariane and –
Dr. Gay: Yeah.
Frasier: – moving to the Ariane VI.
Dr. Gay: Right. So, there is sunsetting going on. But in the new things that they're building, they're not going the fully reusable route for these heavy lift and mid lift rockets. It's the Falcons that are pioneering it, it's the New Shepard, New Glenn, and – oh, and my favorite is the folks over at Rocket Lab with their Electron and –
