Artemis II: 2. Rocket man

Summary

13 Minutes Presents: Artemis II

Episode 2: Rocket Man

BBC World Service – March 31, 2026
Hosts: Maggie Aderin & Tim Peake
Guests: Kristin Fisher (Space Journalist), John Blevins (NASA SLS Chief Engineer)

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Episode Overview

This episode dives into the final countdown before NASA’s historic Artemis II mission—the first crewed journey around the Moon in over 50 years. The hosts explore the excitement at Kennedy Space Center, the mechanics and engineering behind the Space Launch System (SLS), and the transformation of the Space Coast as Artemis ushers in a new era. The standout segment features John Blevins, chief engineer for SLS, sharing both technical and human insights into the rocket’s design, its performance, and the realities of launching people farther than any humans have traveled before.

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Key Discussion Points & Insights

The Scene at Kennedy Space Center

• Kristin Fisher reports live: Buzzing with anticipation, Florida’s Space Coast is packed as launch day approaches. Traffic and even presidential appearances are topics of speculation.
• All hotels are booked, restaurants have long waits, and thousands of journalists are on-site. (03:22)
• White House sources confirm President Trump will monitor from Washington, not attend in person, avoiding further traffic chaos. (03:28)

“It is truly electric... This is all that anybody on the Space coast is talking about.” — Kristin Fisher [03:22]

Artemis II Launch Pad Readiness

• SLS Rocket: The largest rocket NASA has ever commissioned, making only its second liftoff and first with a crew. (02:21)
• Atmospheric confidence: NASA is unusually upbeat; 80% 'go' weather status. (04:42)
• The official countdown clock started—a visual indicator of mission momentum. (04:50)
• Only a minor technical issue (a backup pilot light) is being resolved. Weather is now the chief concern.

Infrastructure & 'New Era' at the Space Coast

• Launchpad 39B and the enormous SLS impress Kristin; she reflects on the evolving ‘skyline’ with SpaceX’s Starship facility now prominent. (06:06)
• The sense of a new epoch prevails as government launches and private space players coalesce on the coast.

“There is just this sense that... this really is the dawning of a new era here along the Florida Space Coast.” — Kristin Fisher [07:03]

Pre-Launch Operations

• Unique to this mission: No final ‘wet dress rehearsal’ fueling; the next fueling is the actual launch. (07:31)
• Tomorrow, pre-launch tanking begins—a stage notorious for surfacing technical gremlins due to supercooled, ‘escape-artist’ fuel molecules. (07:53)
• Current focus: Powering hardware, prepping communication links, and chilling systems for liquid hydrogen and oxygen propellant. (08:35)

“If the gremlins are going to come out, that's when they'll... stick out their ugly little heads.” — Kristin Fisher [09:22]

SLS: Safety & Engineering Details

• Artemis II’s crew capsule—Orion—named “Integrity,” rides atop a European-built service module. (10:11)
• Launch abort system at the tip: Can instantly pull the crew to safety in emergencies. (09:57)
  • Contrasted with the Space Shuttle, which had no such abort option for astronauts.
• Tim Peake recounts the real-life use of an abort system on Soyuz MS-10 (2018)—an incident that safely saved two astronauts, highlighting the value of redundancy. (10:50)

G-Forces & Astronaut Training

• Tim Peake explains launch and abort G-loads (up to 9G in training), describing the intense physical challenge. (11:59)

“You think you're going to take a nice deep breath and actually, you get a tiny amount of air in your lungs because you're being crushed by nine times your body weight.” — Tim Peake [12:53]

SLS Scale and Power

• SLS stands ~98 meters (taller than Big Ben), and weighs 2,600 tons at launch. (13:57)
• It is the most powerful rocket since Saturn V, largely due to voluminous tanks needed for liquid hydrogen. (13:57)

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Interview: John Blevins, NASA SLS Chief Engineer

Begins [14:51]

SLS Reuse, Evolution, and Rationale

• Four RS-25 engines (heritage from the Shuttle era) power SLS. NASA is using the remaining 16 engines, now souped up for Artemis—pushing them to 109% of original power, because they are not reusable on these flights. (15:48)
• The choice to reuse proven Shuttle-era hardware (boosters, engines) balances performance, cost, and existing manufacturing capability. Extra solid rocket booster segments offer more thrust for the higher-energy lunar mission. (17:25)

“Those are hot rods, those are high performance engines... hydrogen is the best molecule on the planet for accelerating.” — John Blevins [17:56]

Artemis I Performance

• The Artemis I uncrewed test (2022) achieved a “bullseye” on velocity target—within 99.97% of planned velocity, described as a perfect engineering outcome. (18:54)

“We hit our velocity at that location within 99.97%. So... just on target. That is a perfect bullseye.” — John Blevins [19:05]

How the Launch Sequence Unfolds

• At launch, most thrust comes from the solid boosters (80%). (20:12)
• Dynamic, high-stress moments include 'transonic’—when shockwaves hit the rocket as it breaks the sound barrier—then booster separation, and throttle adjustments to manage loads and maximize efficiency. (20:12)

What Happens to the SLS Post-Launch?

• SLS is fully expendable—unlike Falcon rockets or the Shuttle, no major pieces are recovered. The focus was on maximum performance to make lunar missions possible, rather than reusability. (22:42)
• Parachute recovery and reuse would require weight penalties and are only viable for higher flight rates (as Shuttle once did).
• Long-term, NASA will keep evaluating reusability as Moon missions become routine.

“For 53 years, nations have aspired to go back to the moon. And this is the first machine set and the first mission design that's capable of doing that in those 53 years.” — John Blevins [23:29]

Weather Constraints for Launch

• SLS is robust in most weather—primary limits are wind direction, and astronaut abort scenarios (e.g., avoiding storms or high seas for splashdown).
• Crew safety in every abort possibility across the globe is coordinated between Houston and the pad. (24:27)

Human Side: The Engineering Team’s Feelings

• John reflects on the rare privilege of sending astronauts to the Moon and the camaraderie among the engineering team.

“There are very few moments where it comes together like this, where we send people back to the moon... It ends with a lot of joy in the relationships with the colleagues.” — John Blevins [25:57]

Fun Question: What Would John Bring as a ‘Luxury Item’?

• John chooses his camera, which coincidentally matches the model the crew will use in space, symbolizing a wish to visually capture these historic moments. (26:50)

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Notable Quotes & Memorable Moments

• “I love the idea of the countdown clock, you know, ticking down those seconds.” — Maggie Aderin [05:51]
• “The skyline is rapidly changing... there is just this sense that... this really is the dawning of a new era here along the Florida Space Coast.” — Kristin Fisher [07:03]
• “If the gremlins are going to come out, that's when they'll... stick out their ugly little heads.” — Kristin Fisher [09:22]
• “You think you're going to take a nice deep breath and actually, you get a tiny amount of air in your lungs because you're being crushed by nine times your body weight.” — Tim Peake [12:53]
• “That is a perfect bullseye in terms of our ability... very proud of the team that put the machine together, understood the latency, understood the software.” — John Blevins [19:09]
• “For 53 years, nations have aspired to go back to the moon. And this is the first machine... capable of doing that in those 53 years.” — John Blevins [23:29]

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Timestamps for Key Segments

• Atmosphere at Kennedy Space Center: 03:22–04:42
• Countdown Clock and Prelaunch Activities: 04:42–09:40
• Engineering & Safety (Abort System): 09:57–13:30
• SLS Scale & Fueling Challenges: 13:54–14:51
• Interview with John Blevins Begins: 14:51
• Shuttle-era RS-25 Engines, Reuse and Modifications: 15:48–17:25
• Solid Rocket Boosters, Design Choices: 17:25–18:47
• Artemis I Performance Recap: 18:54–19:44
• Launch Dynamics Explained: 20:12–21:59
• SLS Post-Launch, Reusability Initiatives: 22:42–24:12
• Weather Constraints: 24:12–25:43
• Engineers' Emotional Reflections: 25:43–26:35
• Luxury Item Question: 26:35–27:17

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Summary Takeaways

• Artemis II is set to revive crewed lunar exploration, riding atop the largest and most powerful NASA rocket since the Apollo era.
• The excitement on the Space Coast reflects the historic significance, while the interviews and technical explanations provide listeners with a deeper understanding of launch preparations and the immense engineering behind SLS.
• The episode blends hard science with human emotion, capturing both the technological leap and the personal thrill of those making history.
• Artemis II is on-track for launch, with weather as the final wildcard, and a world-class team standing by for humanity’s next great leap.

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Transcript

[Tim Peake]

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[Kristin Fisher]

And here we go.

[John Blevins]

And heightened to burn off igniters. Initiate 7, 6, 5, 4 stage engines start. 3, 2, 1. Boosters indiction and lift off of Artemis 1.

[Tim Peake]

We rise together.

[John Blevins]

Back to the moon and beyond.

[Maggie Adairen]

Welcome to the BBC Space Podcast and our special edition 13 minutes presents Artemis 2 from the BBC World Service.

[Kristin Fisher]

25 engines on the core stage and two solid rocket boosters now.

[Maggie Adairen]

I'm SpaceX Maggie Adairen.

[Tim Peake]

And I'm astronaut Tim Peake. And we're following the story of the first crewed mission around the moon in more than 50 years with a new episode every day.

[Maggie Adairen]

We're bringing you the latest news and analysis, hearing from the people who are making it happen, and understanding the details of the mission as it develops in real time.

[Tim Peake]

And we're joined again by space journalist and astronaut corps royalty, Kristin Fisher. Hi, Kristen.

[Kristin Fisher]

It's quite a compliment coming from a Brit. Thank you so much, Tim. And hello, everyone. The clip we just heard was the launch of Artemis 1 back in 2022. The most spectacular launch that I've ever seen. And that was the last and only time that NASA's Space Launch System, or SLS, has been fired into space so far. And so when you look at a picture of the rocket that we're all talking about, it's. It's sitting on pad 39B right now, ready to launch in just a couple of days. And the SLS is the large orange bit with two boosters on either side. It's the biggest rocket and ever commissioned by NASA. And this will be just its second launch and the first with people on top.

[Tim Peake]

Yes, and we're excited because later in the show we are going to be speaking with its chief engineer and we're going to find out just how extraordinary it is.

[Maggie Adairen]

But First, Christian, last time we spoke, you were on your way to the airport to fly down to the Kennedy Space center, ready to witness the launch. We are so jealous. But what's the atmosphere like down there?

[Kristin Fisher]

It is truly electric. It was easy getting down here, but once you get here, this is all that anybody on the Space coast is talking about. Every hotel is full. Every restaurant has 45 minutes before you can sit down to eat. And the biggest thing people are talking about, in addition to what they're expecting to see and what they're so excited about on launch day, is the traffic. And this is a real issue for folks here because these roads can shut down. It can be four hours to get what normally takes about 30 minutes. And one of the biggest questions has been, will President Trump make an appearance at this launch? And if that happens, Secret Service comes in, the traffic times become much, much greater. And so I've actually just heard back from a White House source, and this is on background from a White House official. They tell me that the President will monitor the mission from the White House on Wednesday morning. So it sounds like, as of now, at least based on two sources that I have, that he will not be making this journey. But of course, it's President Trump, and that could always change last minute.

[Tim Peake]

Well, it sounds like it must be a fantastic atmosphere there in Florida. Maggie and I are very envious. But do you think we are still on for a go Wednesday night for launch?

[Kristin Fisher]

As of now? Yes. I mean, we were talking about NASA's confidence level yesterday, how we've never quite heard them this confident about a mission, and that continues today. There was a big press conference last night where they said weather is still 80% chance go for launch. And then the big thing that we all saw visually yesterday at the KSC press site, which is where about a thousand journalists from all over the world have gathered, is that the official countdown clock has actually started counting down to launch. And so just, you know, visually, that's a, that's a really big milestone. And then when you have, you know, some of the top NASA leaders sitting there saying that the only issue that they were working on was a, was a pilot light on the technical side of things. It was one of three pilot lights, which is essentially like a backup light needed if other power outages take place. And two of them were working, but only one was out. And they said that on the technical side that they were working on. So really, Tim and Maggie, at this point, it all comes down to the weather.

[Maggie Adairen]

So it really does look as if it's going to go and this is the furthest we've got. But I love the idea of the countdown clock, you know, ticking down those seconds. Kristen, have you had a chance to go to a sort of 39B yet and actually see where hopefully the launch will take place in a few days?

[Kristin Fisher]

Not on this trip, but I was able to go out there or get, I mean, as close as you can get to the historic LaunchPad 39B during the first rollout, which was back in January. And I just don't think it's possible to put into perspective just how massive not just the rocket is, but the launch pad too. I mean, the infrastructure, the ground systems that are in place to get this thing off the ground is just massive. And we haven't seen anything like that here at the Kennedy Space center, you know, of course, since Artemis 1, but since the Saturn V rocket in the 1960s and 70s. But, you know, just one more point about the infrastructure, the skyline, if you can say that there's a skyline at the Kennedy Space center, the skyline is rapidly changing, even since I was last here in January, because in addition to the big iconic vertical assembly building that everybody associates with NASA and the historic LaunchPad 39B that we're just talking about, there is now a huge complex for SpaceX and Starship, an even bigger and more powerful rocket that's being built right next door to it. And so there is just this sense that as NASA prepares for this first crewed mission to the moon in more than half a century, that this really is the dawning of a new era here along the Florida Space Coast.

[Tim Peake]

Absolutely, yeah. The era of large heavy lift rockets. And yesterday we spoke about wet dress rehearsals, where they put fuel in the rocket. And we had one in February, there was a problem, we had one in March, there was a problem. And this time we're not having a wet dress rehearsal. So the next time they put fuel in the rocket, it's going to be for the launch attempt. And, Kristin, do we know when that's going to happen?

[Kristin Fisher]

That is going to begin tomorrow morning, the morning of launch day. And that's really the moment where if things are going to go wrong on the technical side, that's typically when it begins. I mean, historically speaking, both at wet dress for this mission, but also during wet dress rehearsals and two launch attempts of Artemis 1 back in 2022. The issues always came out during fueling, because as we spoke about yesterday, this is a rocket that consumes elements that are very difficult to contain or what did you say Maggie? I loved it. They're escape artists. They're very small little pesky molecules and they love to escape. So that is really when we're going to see issues if they do come on the technical side of things. But just to give you an idea of some of the other things that are going to be happening during this countdown, you know, a lot of people wonder why does the countdown clock begin? Why did it begin yesterday when we're launching on Wednesday? Some of the things that the NASA teams are doing right now are they're powering up the flight hardware, essentially the spacecrafts and the rocket and the boosters computers, they're checking communication links between all the various ground systems and parts on the rocket itself. And then in order to get ready for fueling tomorrow, they have to prepare the rockets. It's called the cryogenic systems, which are really the cooling systems for the rocket. What needs to happen in order for the rocket to begin being fueled with hundreds of thousands of gallons of this super chilled liquid hydrogen and oxygen. So that's what's happening now. And if everything keeps going according to plan, which it looks like it will, then tanking. That's really if the gremlins are going to come out, that's when they'll, you know, stick out their ugly little heads.

[Tim Peake]

Well, let's hope that those gremlins don't come out. And yesterday we were speaking about the rocket in the context of the wider geopolitical situation with Tim Marshall and that was a fantastic conversation. But today we're going to be looking a bit more at the engineering.

[Kristin Fisher]

One of the most important pieces is at the very top, the launch abort system, which in an emergency at launch would pull the crew module below it away to safety. And of course, let's just hope that's not needed tomorrow.

[Maggie Adairen]

Now the Orion crew capsule sits just below it on top of the European built service module. Together they'll form the Orion spacecraft. That's what will go around the moon and back. Now for Artemis 2, that spacecraft has been named Integrity, which I love and it seems very appropriate.

[Tim Peake]

So we've got the launch abort system, we've got the Orion spacecraft and then everything that is below that makes up the rest of the space Launch system or sls.

[Kristin Fisher]

Two boosters on either side, a huge core stage on the bottom and then a smaller upper stage to kick integrity up to speed once the core stage and booster are spent.

[Tim Peake]

There's something I wanted to pick up on there. Kristen, you mentioned about the launch abort system and I'm sure you're probably watching in 2018, as I was as well, Maggie, when two of my friends, Nick Hague, Alexei Ovchinin, they were launching on board their Soyuz rocket and they had a problem with the first stage booster, which didn't separate. And that was the last saw one of these launch abort systems in operation. But it successfully worked. It carried the crew inside their spacecraft away from the exploding rocket, carried them safely downrange. So we absolutely do not want to see that on Wednesday evening for the launch. But it is good to know that we do have these redundancies built into this rocket.

[Kristin Fisher]

And so important to remember that on the Space Shuttle, they did not have this option. There was no abort option on the Space Shuttle. So if I'm riding tomorrow on this very first crewed test flight, I feel much better knowing that there is an abort system that has been tested. But, Tim, I imagine even if it does abort and abort safely, it's still a pretty violent ride, right? I mean, if there is an abort, you're pulling some pretty high GS, right?

[Tim Peake]

Oh, yeah, yeah. You're pulling high G when the rockets fire, and then also you're pulling high G when you enter back into the atmosphere. Because depending on where you are during that launch abort sequence, you'll be doing a ballistic re entry. And that's quite a high G maneuver. So when we talk about G, we're talking about the force that we feel on our body because of Earth's gravity. And at the moment, everybody on planet Earth, we're experiencing just one G that keeps us stuck to the planet. But you can increase that with acceleration. So in a racing car, if you accelerate or brake heavily, or in a fighter jet, for example, you can increase the G. And what we do in a spacecraft, obviously we're being accelerated up into space. And so when we talk about 4G, that's four times our body weight. That's the weight we're feeling trained for

[Kristin Fisher]

that as an astronaut. I mean, every astronaut has to endure some GS. But this is. This would be more GS than what you typically have to deal with, right?

[Tim Peake]

Yes. Normally for the training we go up to about nine GS. We hold that for about 30 seconds just to practice the breathing technique, because you kind of have to lock your chest into place and you have to gulp in order to try and get some air into your lungs. And it's quite disconcerting. You think you're going to take a nice deep breath and Actually, you get a tiny amount of air in your lungs because you're being crushed by nine times your body weight. So again, we hope that the crews will just be experiencing a nice gentle 4G on their way up to space tomorrow.

[Maggie Adairen]

So, Tim, when you're actually training is in the centrifugal where you're spun round

[Tim Peake]

to increase the g. Yes, absolutely, we're spun round. And so the crews would have practiced this, they would have practiced the launch profile and the re entry profile as well, so that they're very familiar with the kind of G force that they're going to experience. And of course, if you're coming back from the International Space Station, you've just spent a long period, maybe six months a year in zero gravity, so that G feels even more punishing on the way down.

[Maggie Adairen]

I still want to go out there.

[Tim Peake]

So, coming back to the rocket, though, I think what's interesting as well is just the sheer size of it. And to put some numbers on it, it's 98 meters tall. Now, that's just a bit taller than Big Ben. For those listening in the that's 2,600 tons on liftoff, which is going to be the most powerful rocket since the Saturn V. So it is huge. And one of the reasons for its size that we mentioned, these pesky molecules, hydrogen and helium, of course, with hydrogen, if you're going to use hydrogen as a fuel, because it's such a light element, the molecules are spaced quite far apart. And so it needs a big tank to fit all of that liquid hydrogen into it. And I'm so delighted that we're going to be able to talk a little bit more about that with the Chief Engineer of NASA's Space Launch System, John Blevins. Welcome to 13 Minutes from the BBC World Service.

[John Blevins]

I listen to this podcast every episode, so I couldn't help but join.

[Maggie Adairen]

So, John, you're the chief engineer for NASA's Space Launch System, or SLS. We wanted to talk to you today because the SLS is playing a crucial role during launch. So can you tell us about the scale and capability of the sls?

[John Blevins]

SLS is a tremendous heavy lift launch vehicle. As you mentioned, just after launch we take off and we've got very little kinetic energy. It takes this massive capsule that can hold these four astronauts. It takes it all the way to a very high energy orbit so that from there we can boost onto the moon. So it's a very dynamic, very ascent process going all the way beyond low Earth orbit to a high energy orbit.

[Tim Peake]

And John, let's have a think about what's actually kind of powering that SLS right at the bottom there, you've got four of these RS25 engines, and these were the same engines that the Space Shuttle used. In fact, I read somewhere, and perhaps you could tell me if this is true, that there were 16 of these engines left over. So the first few Artemis rockets are going to be using that stock of 16 engines. But you have modified them, haven't you? They're not quite the same as the shuttle engines.

[John Blevins]

Yeah, that's right, Tim. In fact, we did have 16 left over. One of them has never been used on a mission. Fifteen are reusable in the sense that they've been used before on the shuttle program. We do test each one before we go on these missions. We've modified the power level. That's the main thing we've done. Reference our power level with respect to the original power level of the Space Shuttle main engines. So now we're up to 109%. One of those reasons is because we're not reusing these particular engines. And so we want the most energy that we can get out of them, the most boost that we can, and so that disposability allows us to get more energy out of them.

[Kristin Fisher]

John Both of my parents were space shuttle astronauts and in Artemis I, one of those engines actually powered and flew on my Dad's mission in 1985. So there's just so much history there. But I think a lot of people listening to this might be thinking, wait a minute, why in 2026 are we flying hardware into space that was designed in what, the 1970s and flew in the 1980s? Why is that? Walk us through that decision making process and some of the pros and cons that have come from it.

[John Blevins]

Yeah, so we did reuse some pieces of hardware, namely the boosters in those engines. And the boosters are different. In the modifications that Tim mentioned about the RS25, we've got different controllers, different power levels on the RS25s, on the boosters, they're larger. We've got an extra segment for more impulse. This is a very high energy mission. We've got a large payload and so we really want to get it off the ground. One of the reasons that we use that is because the infrastructure of the US can handle that. Right now it's the rockets that we're making. It's the rockets that we did make on the Space Shuttle main engines mainly. And I'm so happy that your father got to fly on One of the ones for Artemis I, that's an amazing story. Those are hot rods, those are high performance engines. The hydrogen is the best molecule on the planet for accelerating, for what we call specific impulse. That's really the gas efficiency, if you will, the mileage that we get out of the rocket. And so using those engines as the highest performance, high thrust engines on the planet were just a logical choice for going all the way back to the moon. On the boosters, they're always functioning and we know how to make them. Well, we have a lot of hardware that we did have left over from the shuttle and it really enables us for a good start out to get this rocket to the moon. So those are very high thrust, largest solid rocket boosters ever built. And it's a overall great system.

[Maggie Adairen]

Speaking of the system, the first flight was with Artemis 1 back in 2022. So can you tell us how well that performed?

[John Blevins]

Yeah, there's a lot of different ways to talk about performance. I like to talk about velocity target because we were shooting for that init cutoff at 1200 nautical miles out. And we hit our velocity at that location within 99.97%. So that's percent. So we were just on target. In fact, that target was so accurate, it was basically a minor frame of the computer. Every 20 milliseconds we send a command to the engines. And so every 20 milliseconds I can set a shutdown command or continue. And so if we would have changed that by 20 milliseconds, we would have been just on the other side of that 100% target. So that is a perfect bullseye in terms of our ability to the target. So very proud of the team that put the machine together, understood the latency, understood the software. The software is written by NASA to manage the machine. It's a really good mission on the first one.

[Tim Peake]

And John, just for our listeners, when they're watching the launch, it's obviously going to go through a number of stages. And those solid rocket boosters that you mentioned, they're kind of just like the blue touch paper. And then after that you don't control them. But for the actual engines, you've got some throttle control there and you've got to control the dynamic pressure that rocket is experiencing on the way up. So in terms of that launch sequence, what are the main things that we should be looking out for?

[John Blevins]

Hey, I'd love to talk you guys through just the launch. You know, after we get to launch, that's a very dynamic event on the launch. And Certainly, that's what we're waiting for. That's where a lot of the preparation goes into. But as soon as we clear that tower, and by the way, we'll get a little bit of vibration as we clear that tower. We're going to have a very reflective environment as we lift off. And of course, we can drift just a little bit with the wind, but we got plenty of clearance. And after we lift off, it's pretty nice for a while. It's a pretty good ride. We slowly increase acceleration. Then we go through this area called Transonic. And this is where shocks develop all over the vehicle. And when that happens, you get a lot of uncommanded forces, right? You get a shock on one side of the vehicle. That's just where the air molecules pile up and they can't talk to each other. And so they form a compression wave, a shockwave. And that is like a force. It's like a hammer hitting on the rocket. And so you go through Transonic and those little hammers are hitting all over both sides of the rocket. And then it steadies out. And not too long after it steadies out the event. You mentioned getting rid of the boosters. They've done a great job. They provide 80% of the thrust getting us off the pad. In fact, if we don't light those boosters, we don't go anywhere, even with Rs25s all the way up to full power. And so once the boosters come off, though, it's all smooth ride. With RS25s, we do have several cases where we throttle, as you mentioned, to control things. One of them is at maximum dynamic pressure. We don't do that all year round. And the winter, the boosters are a little bit cooler. And so we don't actually have to throttle back during Max Q like you may be familiar with the shuttle we do during these transition seasons as the boosters warm up. So there'll be a small throttle bucket for Max Q, and then we'll throttle back just at booster separation to relieve the loads on the attach points as we separate those boosters. And then after that, we are on the way to.

[Kristin Fisher]

John, that was a beautiful explanation. And I got to tell you, those boosters are what I'm looking forward to in some ways the most tomorrow. Because that's where you get that loud crackle, right, that you can feel sort of vibrate in your chest. I love a good solid rocket booster, launch, shuttle had them. And of course SLS and Artemis do, too. John, one of the other Questions that people ask me a lot is what happens to SLS after it's done powering Orion up into orbit. Can you talk a little bit about the fact that this is a $4 billion massive rocket and then what happens? Because in the world of reusable rocketry, this is a bit of a throwback to the past.

[John Blevins]

Yeah, that's a good question. And a lot of people don't understand the physics or the economics of what we're trying to do in reusability. You know, as we fly more reusability becomes a thing and a good thing. And of course, Shuttle was the most reusable that has ever been flown. And so Shuttle, we brought those engines back, we brought the orbiter back. In this case, we'll bring the capsule back and we'll be able to reuse that capsule and a lot of avionics on that capsule in order to do that recovery On Shuttle, particularly, say for the boosters, we owned what we called the NASA Navy, we would go out and recover those, and certainly it was very successful. It was wonderful. We were able to look inside those boosters, learn a lot about those boosters. We flew multiple times a year, one year up to 13 times. Though six was a more sustainable goal. If you're going to fly less than that, you really spend a lot of money. You also lose performance when you do reusability. You carry extra repellent if you're doing the burn to slow down. So we gain a lot of performance. And this machine and this mission needed all the performance we could get. So parachutes or recovery systems, they weigh a lot. And we wanted to make sure that what we did for this mission was return to the moon. You know, for 53 years, nations have aspired to go back to the moon. And this is the first machine set and the first mission design that's capable of doing that in those 53 years. And so that's what we were focused on the most. Certainly as we increase that presence. Reusability is something that the Agency is taking a look at now and will continue to take a look at to make sure that we can have a sustained presence.

[Tim Peake]

It certainly is a phenomenal rocket, Jon, and we can't wait for the launch tomorrow, hopefully tomorrow. What kind of tolerance has SLS got against the weather? What kind of things will you be concerned about in terms of weather for the launch?

[John Blevins]

Well, you know, I'm going to quote the Space Force weather officer yesterday in our L minus 2 briefing, and he looked back at me and he said, SLS is Very robust to launch weather. And that is true. We have a azimuthal placard in terms of the wind direction. We don't want it drifting back toward the pads. We have a little bit limited wind there. We do have some wind for the Orion abort situations where we don't want them to return on land. And so we take a look at the onshore wind component as well. But ultimately our General rule is 34 knots for. And so that's a really good robust weather. But a lot of our weather constraints are not about launch. They're about the path of our crew and where they would abort to. So we don't want our crew to abort in, say, thunderstorms because that would be unsurvivable or high sea states. So we look all the way around the planet at every abort scenario, including the abort once around, to make sure that we're ready to go in weather. So I'm looking forward to a good day. There are some potential cumulus clouds in the area. We will not launch through cumulus clouds with the crew. Those are some restrictions, and that's why you've got the 80% chance of go on Wednesday night locally. But we'll be looking at that entire BORT corridor and our friends in Houston, as well as the local folks here at Kennedy Space center, and we'll all be in sync before we start tanking.

[Kristin Fisher]

Don, you've been at NASA for over two decades. I know asking about feelings isn't necessarily the right stuff, but how are you feeling right now? Is this moment the biggest in your career?

[John Blevins]

Well, it is. You know, you wake up every day and you go to work and you do your best job, and then there are very few moments where it comes together like this, where we send people back to the moon and obviously nobody that worked. The Apollo 17 crew is still around with us. So this is a very unique launch. I will tell you, Kristen, one of the things that really strikes me is we started this journey about the mission and the machine, and it ends with a lot of joy in the relationships with the colleagues. I am just excited to be in the trenches alongside the wonderful men and women that I get to represent that are engineers supporting sls.

[Maggie Adairen]

Sounds fantastic. But, Jo, when we started this series, we asked each other what would be our luxury item that we had taken to space. So I'd like to throw that to you. If you were on this trip going to the movie Moon, what would your luxury item be?

[John Blevins]

Well, you know, my luxury item is kind of going into space. I love photography and so I have a camera that is the same model that our crew is taking into space, ironically. So for me, I guess that luxury item is going on this mission to take the best images that we can. And it's been a pleasure for me having my luxury item down here at Kennedy Space center and seeing the wonderful wildlife as well as the wonderful rockets and launches that occur frequently down here.

[Maggie Adairen]

Yeah, capturing those moments sounds beautiful.

[Tim Peake]

John, thank you so much for taking time out of your schedule. It's been an absolute privilege for us to be able to speak to you on the podcast. Thank you.

[John Blevins]

Thank you. And go Arms too.

[Maggie Adairen]

And Christian, thank you for joining us too. And see you again tomorrow.

[Kristin Fisher]

Oh, thank you, Maggie and Tim, see you tomorrow.

[Tim Peake]

Bye. Bye. As a reminder, we're going to be doing episodes every day for this mission, so do subscribe if you can. Just search for BBC 13 minutes to the moon, wherever you get your podcasts. But that's it for today. So goodbye from me, Tim Peake, Me, Maggie Adairen.

[Maggie Adairen]

The producers are Alex Manfield and Sophie Ormiston and the series editor is Martin Smith.

[Tim Peake]

And our thanks to Hans Zimmer and Christian Lundberg at Bleeding Fingers Music for

[Maggie Adairen]

our theme music 13 minutes presents Artemis 2 is a BBC audio science production for the BBC World Service.

[Tim Peake]

It's 2009 and we're in the German mountains. A man straps himself into a car on the world's most dangerous racetrack. He whispers to himself, it's time to put my balls on the dashboard as he starts the engine. In 15 minutes, he's in an ambulance, unconscious. In 15 years, he's a billionaire. This is Toto Wolff, Formula One's most powerful team boss and the breakout star of Drive to Survive. This week on Good Bad Billionaire How Toto Wolff made his billions. Listen wherever you get your BBC podcasts.