Podcast: Play in new window | Download
Subscribe: RSS
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. When it does launch, it’ll be the most powerful rocket on Earth. Well, until Starship blasts off. Are we about to see the end of single-use rockets and enter the era of reusable rocketry?
Show Notes
NASA: Artemis I (NASA)
Space Launch System (NASA)
Space Shuttle Era (NASA)
Constellation Program: Ares Launch Vehicles (NASA)
Constellation Program (NASA)
VIDEO: Tory Bruno: United Launch Alliance (Fraser Cain)
Falcon 9 (SpaceX)
Falcon Heavy (SpaceX)
New Glenn (Blue Origin)
China National Space Administration
Atlas V (ULA)
Transcript
Transcriptions provided by GMR Transcription Services
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 –
Frasier: Yeah.
Dr. Gay: – Proton. And there, they’re looking at wild, “Let’s catch things on helicopters.” But that’s what we’re gonna talk about in the next episode. So, come back for that in the next episode.
Frasier: Right, right. Now, the SpaceX enthusiasts in the audience –
Dr. Gay: Mm-hmm.
Frasier: – at this point are probably screaming just wherever they are in frustration.
Dr. Gay: You get a whole episode next week, folks. Next episode is all reusable. It’s okay.
Frasier: It’s all reusable. Yeah, yeah, yeah. So, I mean, we are absolutely gonna be addressing the elephant in the room, which is Falcon 9, the reusability of Falcon 9, and of course, the upcoming Starship.
Dr. Gay: Yeah.
Frasier: But we’re in such a funny time. And I think it’s –
Dr. Gay: Yeah.
Frasier: – important that we’re in this weird limbo in-between the old world –
Dr. Gay: Mm-hmm.
Frasier: – and the new world.
Dr. Gay: Yeah.
Frasier: And the old world was, “Lets launch these single use rockets, and let’s try to reuse chunks of them,” and the new world of, “Let’s just launch the same Falcon 9 many, many times, and then let’s launch the Starship and the Super Heavy, which is a fully reusable, two-stage rocket.” And so, we’ll address that next episode, as well as the ideas from Rocket Lab and so on. And I think obviously there’s a case we’ve made in the classic words of Elon Musk, “You don’t fly your aircraft to Paris, and then you throw the whole thing –
Dr. Gay: Destroy it.
Frasier: – in the garbage, –
Dr. Gay: Yeah.
Frasier: – and then buy a new one to go somewhere else.” But a rocket is not an airplane. It is going far faster. It is experiencing a lot more stress on all of the metal, and all of the parts. One does not simply reuse a rocket.
Dr. Gay: And there’s the added difficult with, for instance, the SRBs – and this is also true for the Falcon 9 first stage – that they’re headed towards the ocean on their way back to ground. And the SRBs had parachutes on them. And they were literally scooping them out of the ocean after they had been exposed to salt water. And salt water is one of those amazingly corrosive substances. The Falcon 9s get their reusability by landing on a barge. And that is technology that when a lot of these rockets were developed, the processes just weren’t fast enough to handle. And the SLS actually has the equivalent of a G3 processor from the ‘90s in it. So, that is not fast enough to do the kind of –
Frasier: Right.
Dr. Gay: – maneuvering necessary to land on a barge. So, they’d be trying to recycle something dumped into the ocean, partially corroded. And that’s a lot of work.
Frasier: Not worth doing.
Dr. Gay: No.
Frasier: And if you’re gonna try to save some fuel in your booster rocket, then you don’t get the full amount of your launch capability. You’ve got a partial ability to launch. And then, you’ve got to save some of your fuel for you to be able to land the rocket. And I think one of the feelings that I have is that we’re in this weird in-between stage between needing to launch rockets and space-based construction. Institute resource –
Dr. Gay: Yes.
Frasier: – utilization, space –
Dr. Gay: Yes.
Frasier: – construction. And our need to launch rockets off of the earth is going to decline into the future. And we may get to a point where we just no longer need to launch rockets, except for carrying human beings to space if we want to.
Dr. Gay: Yeah.
Frasier: But everything else is being manufactured in space. And so, you’ve got this huge capability, reuse capability, and yet nobody’s actually needing to go to space because everything is already out there, being shifted around where it’s energy inexpensive. But isn’t it weird? I mean, I guess we talked about this New Glenn, we talked about SpaceX, we talk about their level of reuse, Electron, again, we’re talking about this next week. But it’s –
Dr. Gay: Yeah.
Frasier: – still, I think from our perception, and from a lot of people’s perception, SLS is old tech, old methods, huge expense, –
Dr. Gay: Yes. Yes.
Frasier: – and less reuse. How do you respond to that, Pamela?
Dr. Gay: I think the way I respond is I point out that SLS also lacks the flexibility that we see in a lot of other rockets. We often see with the Chinese Long March series. And it is truly an entire series of different rockets. With the Long March series, they reconfigure those in all sorts of different ways, changing how many side rockets – they call them “Strap-on rockets” – that they have onboard, all of the different combinations. This kind of flexibility, by having different components that are kind of plug and play, allows them to have a lower cost, highly versatile system, compared to having, “This design is only used for this thing. This design is only used for this thing.”
So, I think there are other techniques that you can use to change your costing. We see similar diversity with the Japanese rockets to a certain degree. Many nations are trying to figure out how to have the side boosters, the core booster, and a variety of configurations to take them to varying degrees of medium lift and heavy lift. And I really am loving these plug and play kinds of designs that we’re seeing that allow this diversity. So, I think there’s multiple techniques. And with heavy lift, like you said, you want to use every ounce of fuel you can to get off this planet.
Frasier: Right. Right. And so, if the payload, if it’s a $10 billion space telescope for example, and the thing that matter is that you get this payload to precisely the right orbit, then spending a billion dollars, or half a billion dollars on your launcher is worth it.
Dr. Gay: Yes.
Frasier: But if you’re trying to launch 40,000 internet satellites, then the economics change.
Dr. Gay: Yes.
Frasier: Yeah.
Dr. Gay: Yes. And again, it also depends on what orbit you’re getting to, because they aren’t putting those 40,000 satellites up in geo, they’re putting them in lower earth orbit. And it takes a whole lot less fuel to get there.
Frasier: Yeah. I mean, there are a lot of missions that have been proposed right now, that there is just no launcher capable of doing it.
Dr. Gay: Yeah.
Frasier: Even the Space Launch System, with its block 1 configuration, couldn’t do some of these missions. Things to the outer planets, heavier cargo to the moon, things like that. You’re gonna need to get to the block to be, which is the heavier upper stage, before you can even pull off some of these bigger missions. The –
Dr. Gay: Yes.
Frasier: – SLS is amazing, but it’s still not as powerful as the Saturn V.
Dr. Gay: And we won’t have those additional heavy lift capacities until they turn on the factory lines to build the new RS-25 engines, to build the new casings and electronics for the SRBs.
Frasier: Yeah.
Dr. Gay: They’re still in the reuse stage. So, this is where next week, we are going to be taking a look at Starship. And this week, we have to say, there are other heavy lift vehicles in the process of being developed. Arianespace is looking at what they can construct, China’s looking at what they construct. Russia, we’re going to set them aside –
Frasier: Right.
Dr. Gay: – and say, “We don’t know what’s going on over –
Frasier: Yeah.
Dr. Gay: – there.”
Frasier: Russia says a lot of stuff.
Dr. Gay: Right.
Frasier: Yeah.
Dr. Gay: Right.
Frasier: That we don’t take very seriously.
Dr. Gay: Yes.
Frasier: But China has a lot of very powerful launchers right now, and even more powerful ones in the works for their missions to the moon. Yeah. Yeah, I’ve gotta come clean here, right? I feel an enormous amount of – can you have an enormous amount of ambivalence? I feel extreme ambivalence in this situation, because on the one hand, this next generation of reusable rockets don’t exist, and we don’t have the capability to go to interesting locations, and haven’t had it for decades.
Maybe 50 years. That finally, the SLS is the first rocket that will give us that capability. Falcon Heavy is kind of there, but SLS is the machine that would let you send out an interstellar probe, or go to send a heavy orbiter to Neptune, or visit multiple moons of Jupiter, etc. etc. etc. And we just don’t have that. And yet, it does seem bonkers to me to throw away your rocket every time.
Dr. Gay: And more than that, they limited their potential with SLS by saying they had to reuse shuttle parts. They only get four launches from that reuse. And the factory lines have been shut down. They’ve been off since 2017, I think?
Frasier: Yeah.
Dr. Gay: And so, those people are doing different things. It was meant to keep those folks employed. So, we have a rocket that has late ‘90s electronics, and doesn’t have the versatility because of the constraints put on it, largely for political reasons. SLS, Ares, either of those two series that were planned could’ve been amazing, if they gave the engineers the chance to say, “We’re using modern processors. We’re using modern fabrication. Let’s see what we can create using –
Frasier: Mm-hmm.
Dr. Gay: – today’s technology.”
Frasier: Yeah.
Dr. Gay: And that I think is the real place where everyone else is going to be able to fly ahead of us.
Frasier: Yeah. And everyone poopoos the SLS, but if you said, “Sea Dragon,” right? Now, they’re excited again. Which is of course this gigantic, expendable rocket that took off from the ocean and lifted ludicrous amounts of weight into space. And it was featured in it for all mankind. Suddenly, now you’ve got their attention again. So anyway, all right. Let’s wrap up this week, and hang on that ambivalence. We’ll set it –
Dr. Gay: Yeah.
Frasier: – aside, and next week, we will come roaring back with a further investigation into reusable rocketry, and the case for not throwing away your stuff every time –
Dr. Gay: Yeah.
Frasier: – you use it. Thanks, Pamela!
Dr. Gay: Thank you, Frasier! So, once again, I’d like to say not just thank you to you Frasier, but thank you to all of our patrons out there. You are the ones that allow us to do this week after week. And this week, I am going to thank by name, Kyle Saint George, Arkham Fantasy, Daniel Donaldson, Laura Smith, Jeremy Gurr, Jorn Aslaxan? I’m sorry. I really like you. Your name is a deep mystery. John Lawson, James Roger, Steve Martini, Richard Alexander Hubbert, Bjor Andre Lizfall. Folks, you can put pronunciation guides in Patron where your name is.
Frasier: All the complex names showed up over the summer. Yeah.
Dr. Gay: Yeah, yeah! Theodore –
Frasier: We truly have an international audience.
Dr. Gay: Yes. Theodora Lip Barbara, James Sidel, Bill Cameron, Robert Wegner – you’re giggling. I understand why you’re giggling. Glenn Border, the – oh no. The Breviloquent Caveman? Folks, I’m going to make a plea. And I’m going to come back and try your names even more in the next episode.
Frasier: Oh, awesome! All right!
Dr. Gay: Please put pronunciation guides, please? Please? I heart –
Frasier: All right.
Dr. Gay: – all of you.
Frasier: All right. Well, we’ll see you next week, Pamela!
Dr. Gay: Okay. Buh-bye!