---
title: 'Touring the Vulcan Rocket on the Launch Pad - Smarter Every Day 297'
source: 'https://youtube.com/watch?v=Bh7Xf3Ox7K8'
video_id: 'Bh7Xf3Ox7K8'
date: 2026-07-21
duration_sec: 2203
channel: 'SmarterEveryDay'
---

# Touring the Vulcan Rocket on the Launch Pad - Smarter Every Day 297

> Source: [Touring the Vulcan Rocket on the Launch Pad - Smarter Every Day 297](https://youtube.com/watch?v=Bh7Xf3Ox7K8)

## Summary

In this video, Destin from Smarter Every Day tours the ULA Vulcan rocket on the launch pad with CEO Tory Bruno, exploring its design, engineering challenges, and the upcoming launch. The video provides an in-depth look at the rocket's components, including solid rocket boosters, BE-4 engines, and the mobile launch platform.

### Key Points

- **Introduction to Vulcan Rocket Tour** [00:00] — Destin walks up to the Vulcan rocket on the launch pad with ULA CEO Tory Bruno, who is an engineer by training.
- **Vulcan's Role and ULA's Transition** [01:40] — Vulcan is important for ULA as they retire Atlas and Delta rockets, which are workhorses of the American launch industry.
- **Rocket Dimensions and Solid Boosters** [05:54] — Vulcan is 202 feet tall (20 stories) and 18 feet in diameter. It uses GEM 63XL solid rocket motors, the longest monolithic rocket motors ever flown.
- **Mobile Launch Platform and Assembly** [08:16] — The mobile launch platform weighs 2.5 million pounds. The rocket is assembled vertically in a building, then rolled out to the pad.
- **Acoustic Water Suppression System** [12:00] — The system dumps about 10 swimming pools' worth of water to absorb acoustic energy that could otherwise kill people nearby.
- **BE-4 Liquid Engines and Thrust Vector Control** [14:15] — The two BE-4 engines can gimbal for thrust vector control, while the solid boosters have fixed nozzles canted to pass thrust through the rocket's center of gravity.
- **BE-4 Engine Development Challenges** [18:19] — BE-4 engines took a long time to develop, partly due to solving the 'screech' problem—high-frequency acoustic oscillations in the combustion chamber.
- **Why Methane is Harder than Kerosene** [22:57] — Methane combustion is more energetic and prone to screech compared to kerosene, requiring careful mixing and baffles in the face plate.
- **Engine Cooling and Additive Manufacturing** [25:05] — The BE-4 uses fuel-rich film cooling and additively manufactured channels for cooling, which provide superior heat transfer compared to traditional brazed tubes.
- **Future Videos and Personal Moments** [29:49] — Destin plans a future video on cryogenic refueling. He shares a personal moment riding a ride with his dad at Epcot.

### Conclusion

The Vulcan rocket represents a new era for ULA, combining innovative engineering solutions like fixed-nozzle solids and methane engines. The tour highlights the complexity and elegance of modern rocketry.

## Transcript

In this video, we're going to walk right up to a huge rocket on the launch pad. up to the hot, naughty bits. That's what I call it. They've been in development for a really long time.
right up to it with the guy over the whole company that did it, Tory Bruno. He's extremely smart, he's an engineer by training, and and he knows his stuff.
of aerospace development. There's all kinds of rockets being developed by SpaceX and Blue Origins and all these other companies, and they're making new rockets, which is awesome.
they're being flown for the first time. This rocket that we're going to see today is called the Vulcan Rocket, and this is You may remember in a previous episode of Smarter Every Day, we got to see
In fact, these are some of the chips that came off of some of those mills They bump form them, they roll them, they make them into big cylinders.
The rocket that we're about to see launch, we saw it being made in the factory. Oh, those big plates that you saw machined and you saw bent and you saw anodized have to get friction stir-welded together into a barrel to form an atlas booster.
Or in the case of what you see over there, right now is the Vulcan Okay, so that is the first vertical assembly of Vulcan.
The Vulcan rocket is especially important for ULA because they're retiring their These are workhorses of the American launch industry, and they both have great track records of being reliable launch platforms.
Yes, Tory Bruno is the CEO of United Launch Alliance, and this is With all that being said, there's speculation in the industry that somebody If they do, we don't know who's going to be launching Vulcans in the future.
We know Vulcan is going to persist, but we don't know what company name All that being said, I want you to understand something about Tory Bruno. I've had private conversations, and he is very kind and excited about other rockets
So don't think of as watching a rocket tour on the pad with a CEO of a company. Think about you being able to walk up to a really cool new rocket,
rocket nerds in the country. He's a nerd's nerd, and he's a really fun person to tour a rocket pad with. to come along, and he's going to help me by being the second camera guy.
I mean, he loves building things, and he worked on the James Webb space telescope. So being able to share this with him is a very special thing for me.
It's two days before launch. very early in the morning. So we found a patch of time right after sunrise or during sunrise,
So it was a little difficult to record sound, but the reveal Let's go get Smarter Every Day and go to the pad and learn about the Vulcan rocket.
Okay, here we are before sunrise down in Florida. That is pretty cool looking. As we drove up on the Vulcan, I was just struck by how awesome this machine is.
it's just incredible. But I also want you to notice there's large lightning protection system This is probably the best shot we're going to get of that.
Also, speaking to Tory, there's a guy around here somewhere Oh, we're going mustache today. Someone on the staff has to grow one, and no one stepped up.
Can Can we just go look? Yeah, we can walk right up there. I think I may have seen one at Decatur. Yeah, I'll take you underneath platform. Let's do that?
You've got the patented Tory hard hat. Yes, I do. Yeah, once we get to the yellow line up there, we'll put a hard hat on you.
So we've got We've got the Vulcan here. So we have the Vulcan here. [T] Yeah, so you see the four towers and the two sets of cables.
It's bigger than it looks. [D] Really? They feel like that feels small. A confinement?
[D] Oh, it's amazing. Okay, and what is this tower over here? So the four towers are grounded, and then they're connected electrically
So that whole thing is lightning protection. [T] This tower, that tower, that tower, that tower. Everything's bigger than it looks because there's nothing
That rocket is 202 feet tall, so that's 20 stories tall. Okay. And about 18 feet in diameter, 5. Obviously, it's not fueled yet, except for the solid.
Those are the GEM 63XL, extra long. These are about 7 feet longer than the GEM 63s we've been flying on Atlas so far. [T] 63 inches in diameter was the original design of that original rocket motor
These are the longest monolithic rocket motors ever flown. [D] Which is good because you don't get cracks in the...
There's no big O-ring joints like there were on the shuttle segments So it's a lot more weight-efficient, so you don't have that big joint in there.
It's 109,000 pounds of propellant in each one of them. So that's a lot of energy tied up in these guys. And all of that, 50 tons of propellant is expelled in less than two minutes,
[D] And their thrust vector, the nozzles- [T] No, these are fixed nozzles because we have So that's enough control authority to get us all our pitch, yah, and roll.
Because most solids, like on the ones you see on SLS and the ones you see on the shuttle, they were gimbled, [T] Yes, they often are gimbled. When we flew the Delta with its solids, we had fixed or gimbled
depending on what we were doing and how many, and the same on Atlas. We got plenty of control authority on the liquid engines. So weaseled dad in here with me to do the B roll, right?
I think it's hard hat time. [DAD] Okay. [DAD] All right. [T] All right. [D] Let's do that.
[D] You can hold the camera down, dad. [DAD] Okay. That's great. That's the MLP or mobile launch platform.
So obviously, the rocket's not fueled with the liquid propellents when we move it out here, but the mobile launch platform is still two and a half million pounds.
Rockets like 100,000 pounds empty, plus the solids, which are 117,000 pounds each. [T] Only the upper stage.
You either have to have it stretched and supported mechanically or pressurized because it's that very, very thin, as thin as 14,000 stainless steel.
The first stage is rigid. That's that ortho-grid, the rigid aluminum structure, the 2000-series But the upper stage has to be pressurized.
The doors are closed right now. That's where we assembled all of this because it's too big So the first stage, the upper stage, the payload faring, the interstage all
They go to that building, we stack them vertically, then we bring in the solids, stack those, and then the last thing we do is bring in the fully encapsulated
payload, in this case, Paragren, underneath the payload faring. [D] That's awesome. [T] And then that gets stacked. So when it's all done, doors open, then it rolls out here at a blistering
[T] Takes a couple of hours to do it because we come real slow to Somebody asked me the other day, they go, how long does it take to
Eight years? So if you go way, way up the topmost one up there, that white one that looks bent,
that's a flexible, what we call ECS or Environmental Control System duct. Temperature, humidity, stuff like that. Certain payloads, especially optical ones, you got to keep them super duper dry.
umbilicals for the propellants. You've got umbilicals for all the electrical systems and the data and And then, of course, up there in the middle, you got a ground wind damper
[D] That's a mechanical coupling there. Okay. [T] Because winds can get pretty high out here. [D] Here, how many hours out are we right now?
[T] We're going to go at 2:18 in the morning on Monday, so we're a ways out. [T] So that's ground wind damper. And then above that was all propellant and power and electricity and data.
[T] Then as we come back down, then we've got more of the same. Then this is also different than what you're used to on shuttle or even Artemis or even Delta IV heavy, where we have mechanical arms that would
These will disconnect and then fall down out of the way, part of it passively, so that we don't have that complicated set of systems and hydraulics
[T] We're going to go until somebody stops us. All right, I'm switching back to wide angle. [D] Yes. That's for for acoustics, correct?
So we call that the Acoustic Water Suppression System. We're going to dump about, I guess we're going to dump about 10 swimming pools [T] And that's all about the acoustic energy that would come out of the Rockets,
Water is almost the best, you know, acoustic energy absorbing And the reason that's important is because where we're standing right now,
So if the fire didn't get us, the sound alone would just kill us right here. We get massive brain hemorrhage, that stuff. Without all of that absorption, that energy would reflect right back on the
[T] That's what it's really about. [T] Yeah. [T] Yes, we are. That rigid platform will go away.
That grading you see, that goes away. [T] And if you look to your right, that's the outlet to the flame trench right there. And out of that thing and It blows the lawn, knocks the fence over.
[D] Sounds great. We're going to get about a million and a half pounds of thrust out of those. Grounded, All right, let me switch to my tighter lens.
Okay, so GEM 63s, they're canted. [T] Gem 63, XL. [T] Yeah, so that way we're getting the center of gravity from them through the average center of gravity because you know that for the rocket,
it's moving because we're going to dump all that propellent in five minutes. So we pick the optimal place to pass the solid's thrust vector through so that the BE force don't have to fight too much of that on the way up.
because a lot of solids on big things like shuttle and SLS, they have nozzles that move so you can do what's called thrust vector control.
Look back at the bottom of the rocket. Those two silver things right in the middle, those are the BE4 liquid If we think about what's going on here, you can actually move those.
And what you can do with that is fascinating. You can vary the thrust so you can spin the vehicle in one way or the other. You can also do things like this.
You can even roll the vehicle by how you swing these bells Now, the design choice they make, I think, is very elegant and very simple.
They are thrusting the solids through the CG of the rocket When you first start, if you look at a cross-section of the rocket, you load It's a very heavy rocket, and the CG is really high, though.
It's towards the front of the solids because you think about how long the rocket is, and you've got the centaur upper stage, and it's fully loaded. But as you start burning and dumping mass out the back,
the CG is going to slowly walk forward. That's fascinating. designing the system, I'm just going average out and shoot the middle of where And that's where I'm going to thrust my solid rocket boosters through.
to overpower, so to speak, those liquid engines in the middle. the vehicle and roll pitch or you all or anything like that with your solids.
You're just trying to add forward momentum to the vehicle. The fact that they canted that by the way, means if you have, let's say it's If you have a sign of three degrees, that means you're pinching in with about 5%
of your total solid rocket thrust, which means the design of the core has to be able to handle that compressive force, which I think is fascinating. I'm sorry, I'm geeking out right now, but this is a very complicated problem,
Another thing to think about is when you're down at sea level, a four degree cant on your rocket, your rocket nozzles, that's going to But when you get up five miles in the atmosphere, you've got less mass
So that same cantover of the nozzles, you're going to get a much different So they're probably not averaging that thrust spot between the beginning and
the end of the CG because the response is different as you go up in altitude. They probably have an optimized spot, and that's where they're thrusting It's a very simple, elegant solution to make these solids
And it almost makes me empathize with the challenge that the guidance and control engineers have trying to figure out this control algorithm. And everybody knows that solid propulsion and liquid propulsion
That's where the cool stuff is. I'm joking right now. Anyway, obviously, this is an amazing problem, and I'm excited just to hear Tory talk about it because I'm learning, and I'm hoping you're learning, too.
of those solids, plus the 1.1 million from the combined pair of BE4s. fully fueled at lift off.
We'll have about 2 million pounds of thrust, so it's not going to leap off So you'll see it gently come off the pad and go. [T] That's the max, yeah.
[T] It's physical space around the rocket. we knew that's what it would be. [D] Let me ask you about the BE4s.
It took a long time to get them to you. [T] It did. We love them. They're good engines now that we got them. My understanding is, and don't let me hurt your feelings too much
My understanding is those things in testing, they've got a lot My understanding is one or two of them has four seconds This is what I was asking Tory.
A horizontal rocket engine test is when you have a huge reaction mass and you horizontally mount that rocket engine up against that mass and you fire it A vertical test test is when you hang the engine from your reaction mass
like this, and you can test it in the configuration that it's going to launch. [T] What's really more important than whether they're horizontal or vertical is how they interact with the rest of the rocket because you're moving
Remember, it's going to dump all of this, right? We got 86,000 pounds of LOX. We got 73,000 pounds, gallons, I pounds, 86,000 gallons of LOX,
All that's gone in five minutes. So the flow rate through these engines is humongous. And the orientation of the liquid rocket engine in its pumps
What really matters is how it interacts with the rest of the rocket. And of course, that's the one thing you can't test until So things like Pogo interactions with the big fluid columns.
[T] Pogo is the tendency of a long fluid column to want to oscillate And so that's one of the things we have to worry about with these big, long, liquid,
fueled space launch vehicles because they're so big and they're so long. So this thing is oscillating as we're Flowing it through the pumps
in the rocket engine and we're throttling up and down, that fluid column wants to take all that energy and it wants to isolate or oscillate. And so we have Pogo absorbing features in this design.
how it interacts with the structure, which is another potential source, You can have Pogo where the feed to the pressure, the feed
to the engine is oscillating because that fluid column is oscillating. You can get buzz, where the engine is interacting with the structure, and You can get screach, we call.
Which is an acoustic phenomenon inside the combustion chamber of the engine, which was one of the problems we had to solve on this engine because no one had
successfully overcome Screech in a large methane engine before. [D] At what frequencies are we talking about? [T] Thousands of hertz. [T] Yeah, because it's a thing that happens right at the flame front where you sprayed
into this combustion chamber, the LOX and the methane, of combustion where it's mixed, and they're like little detonations. It's a tremendous amount of acoustic energy, and you can get
standing waves transverse or radially inside that combustion chamber. Not so much longitudinally, because the end of the chamber is open. So there's nothing to reflect off of.
But those other modes can get going in the tens of thousands of hertz. And if you let that happen, you can rip that combustion chamber [T] So that was part of what took a while to get the BE4s was to solve that problem.
And the way you deal with that screach problem in a combustion chamber is by carefully controlling your mixing, carefully controlling the pressures you operate at, but also by putting baffles and features in the face plate of the
[D] Just like the Apollo engineers did with the F1. Yeah, this is not a phenomenon unique to methane. [D] Why? Why is it harder than, say, kerosine?
[T] Because of the chemistry The energy of that combustion It just tends to be much more lively, if you will. In that rough, rapid combustion zone, you can get a lot more acoustic energy
generated instead of the energy going into heat and expansion. Stoichiometrically, what are we looking at? Oxygen to- [T] This is close to a three to one ratio.
In practice, the stochiometric ratio is always Ideally, it's always different than that, but you can't have 100% combustion efficiency. But you can guess because I told you how much propellant was in
[D] So do you use film cooling on these engines? [D] So film cooling is when you run it rich, I would say? So it's not a fuel-rich.
We do use fuel inside the bells to cool the bell and to cool the outside [D] So let me zoom in real quick here.
That's Incanel, right? [D] You're not supposed to tell me what that is. So don't tell me.
All I know is... I do know that. [T] That's a very aerospace Alloy, INCO. That was for what?
So we could do our first super- [D] Even the blankets on the F1. The reason I bring that up is because INCENEL is very, very heavy.
[D] Okay. [T] I'll say that the weight is not too bad. Then there's a whole program that Blue Origin is involved in
right now with us to continue to lower the weight of the engine Because right now, looking at it, I can tell I'm not going to pretend I haven't.
My understanding is back in the day with a lot of the Apollo engines, You would run the fuel up through the thing itself. This one is welded around the outside. It's my understanding.
[D] Let's talk in general terms. it's got poor heat transfer properties. That's also true here, even though it's not kerosine because it's
[D] Is it the heat capacity or the heat transfer coefficient? It is the thermal capacity as well as the conductivity of fluid. When we look at an upper stage engine like RL10, on this RL10,
you would still see those brazed tubes, which is absolutely the most weight-efficient way to circulate that coolant, like the radiator in your car. However, that is a handcrafted, craftsman, skilled guy bending little tubes,
So ultimately, what you want to move to or machine channels or additively manufactured channels, even better yet, in order to be almost as good, but
And so this engine does not have little brazed tubes like an RL10 or like an F1. And even our RL10- [D] Rectacular. [T] Yes.
[T] And even that upper stage, the RL10 that's air-jet rocket dying, now L3, will move in our CX upgrade in a couple years to that configuration, So it cost us a little bit of weight, but boy, we pick up a lot of
[D] 3d printing? [D] What's interesting about 3D printing is the surface finish of the metal, and it will create turbulence inside, and you want turbulence inside.
I forgot about your fascination with laminate and turbulent flow. [T] As a matter of fact, we've been a little bit I'm not going to talk [T] But we've been a little bit surprised as we have been developing that,
that we get superior heat transfer and superior cooling conditions when we additively manufacture the channels that we didn't really expect. [T] Yeah.
It's offsetting a little bit the weight by getting better performance because that affects performance, especially on an expander cycle like RL10, which is subject to the cube-square limitation on how much thrust you can get out of it.
It's so good. It's so fun. [D] You're going to keep it up? So the next launch won't have it because we were in a hurry to build that booster
We do this right now. We take it in the paint booth and we mask it all off, and the guy And it's not too bad, but it takes a little bit of time to do that.
For missions like this, we got plenty of extra weight. I mean, that's less than a couple of hundred pounds of paint on there. But going forward, we're looking at other ways to do it, maybe
automated sprayers and things so we can do it fast and do it every time we have You'll see this, every other one, every third one will do the paint job on it. But this mobile launch platform is deeper, the structure that you see right here,
The one we have for Atlas, when you want to maintain all the piping and plumbing and data lines and stuff that's in the base, when you're in on
You can't get up in there, and it's awful. That thing is built so that we can walk around inside. Yeah.
If this were back in the VIF, we'd open a hatch and you could get [T] Yeah, this is brand new for Volcan. The whole thing is new? It was so cool to be this close to the rocket, but we had two days
First thing that happened is Tory took time to explain to me how And that's so awesome that I'm going to make a whole video about that.
Now, cryogenic refueling in orbit is going to be a big deal So I first wanted to understand how you cryogenically fuel In order to see that, Tory actually let me go into the control room, and we learned
It's a complicated process, and I learned things I had no idea were So I'm excited to show you that in a future video. I think you'll dig that.
We went to the Visitor Center there at NASA's Kennedy Space Center. That was incredible. We also got to do something that was really special for me in particular.
When I was a kid, my dad took me to Disney's Epcot Center, and there's this There's this little dragon, and he goes around, and you're I remember that with my dad when I was a child, and I really
Now that I'm an adult, I just want to feel like a child again. We rode this ride together, and it was really fun. I don't know why, but doing this with dad made it that much more special.
And when it came time to see the launch, I have never been this close to a large scale rocket launch, and I've also never filmed one in slow motion. Before I show you that, I want to say thanks to today's sponsor.
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Every Day, and I'd be grateful. Thanks. The launch happened really early in the morning, 2:00 AM early. We had seen it on the launch pad, and we were together.
There was basically nothing but water in between us and the rocket, There it is, way out there. my best to try to get focus set so we could capture a lift off.
I've got a Phantom Miro right here, 1,000 frames per second.
It meant a lot to watch this launch, and it meant even more because I was watching it with my dad. Wow.
Can we figure something out where I can see how they do that? In fact, I have personally selected a compliant screening field compliant screen for you to watch. Sounds great.