Why the Vulcan's Solid Nozzles Don’t Gimbal - Smarter Every Day 297

In this video, we're going to walk right up to a huge rocket on the launch pad.

Not only are we going to walk up to it, we're going to walk right

up to the hot, naughty bits. That's what I call it.

We've got two liquid engines, two solid engines.

They've been in development for a really long time.

And not only are we going to walk right up to it, we're going to walk

right up to it with the guy over the whole company that did it, Tory Bruno.

Tory Bruno is a legend in the rocket community.

He's extremely smart, he's an engineer by training, and and he knows his stuff.

Here in America, we are right in the middle of an explosion

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.

That we are living in an era where new rockets are being developed and

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

the first time it's ever been flown.

You may remember in a previous episode of Smarter Every Day, we got to see

the Vulcan Rocket being manufactured.

In fact, these are some of the chips that came off of some of those mills

that were cutting that ortho-grid pattern that would ultimately become the rocket.

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

first-flight liquid oxygen tank. That's it.

Okay, so that is the first vertical assembly of Vulcan.

Right.

And now we're going to get to see it being flown.

The Vulcan rocket is especially important for ULA because they're retiring their

Delta and Atlas class rockets.

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

the first launch of the Vulcan rocket.

With all that being said, there's speculation in the industry that somebody

might buy United Launch Alliance.

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

they'll be flying under.

All that being said, I want you to understand something about Tory Bruno.

He is a rocket fan through and through.

I've had private conversations, and he is very kind and excited about other rockets

in the industry when the cameras are off.

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,

and you're doing it with one of the smartest, most well-informed

rocket nerds in the country.

He's a nerd's nerd, and he's a really fun person to tour a rocket pad with.

Another thing that makes this really special for me is my dad's going

to come along, and he's going to help me by being the second camera guy.

If you've seen my dad in previous videos, you know he's wicked smart.

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.

So let's go to Florida's Cape Canaveral Space Force station.

It's two days before launch.

The only way we can fit this in for Tory is if we did it

very early in the morning.

So we found a patch of time right after sunrise or during sunrise,

actually, and it's extremely windy.

So it was a little difficult to record sound, but the reveal

of the rocket is just incredible. So here we go.

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.

Check this out.

That is pretty cool looking.

Yeah, the lights make it look amazing. That's incredible.

As we drove up on the Vulcan, I was just struck by how awesome this machine is.

And to know that we had seen it being built in the factory,

it's just incredible.

As we drove up, we had to show someone our credentials.

But I also want you to notice there's large lightning protection system

towers all around the rocket.

This is probably the best shot we're going to get of that.

So remember that for when Tory is talking about it later.

Also, speaking to Tory, there's a guy around here somewhere

with a cowboy hard hat on.

We just got to find him. Hey, Tory.

Oh, we're going mustache today.

Someone on the staff has to grow one, and no one stepped up.

So it's you.

So this is Volcan.

Can Can we just go look? Yeah, we can walk right up there.

I've never seen a BE4.

I think I may have seen one at Decatur.

We can go right up underneath. Can we really?

Yeah, I'll take you underneath platform. Let's do that?

Yeah, come on.

Sounds great.

You've got the patented Tory hard hat. Yes, I do.

I think at a certain point, they're going to make me wear a hard hat, right?

Yeah, once we get to the yellow line up there, we'll put a hard hat on you.

Okay, so before we go further here, can I just look at this?

So we've got We've got the Vulcan here.

Let me make sure my focus is working.

So we have the Vulcan here.

That cable over the top, that's the lightning protection system?

[T] Yeah, so you see the four towers and the two sets of cables.

That is the lightning protection system.

It's bigger than it looks.

When you look at that inner square, it looks tight, but it really isn't.

[D] Really?

[T] But that is the one thing that the astronauts tell me make them nervous.

They feel like that feels small. A confinement?

But it's not. We'll go right through the center of that.

[D] Oh, it's amazing. Okay, and what is this tower over here?

[T] It's all four towers.

So the four towers are grounded, and then they're connected electrically

to these cables that you see that surround the whole launch pad.

So that whole thing is lightning protection.

[D] Okay.

[T] This tower, that tower, that tower, that tower.

[D] Got it. [T] It looks small.

It's not.

Everything's bigger than it looks because there's nothing

around here to measure it by.

That rocket is 202 feet tall, so that's 20 stories tall.

[D] 20 stories tall? [T] Yeah.

Okay. And about 18 feet in diameter, 5.

4 meters in diameter.

Obviously, it's not fueled yet, except for the solid.

So we got two solids hanging there.

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.

[D] What does the 63 mean?

[T] 63 inches in diameter was the original design of that original rocket motor

that these were designed from.

These are the longest monolithic rocket motors ever flown.

[D] So they're not segmented? [T] Not segmented.

One piece.

[D] Which is good because you don't get cracks in the...

I didn't know that.

I thought these- [T] Yeah, so you don't have to seal them.

There's no big O-ring joints like there were on the shuttle segments

or on Artemis's solids.

So it's a lot more weight-efficient, so you don't have that big joint in there.

And they're faster to make.

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,

about a minute and 50 seconds.

[D] And their thrust vector, the nozzles- [T] No, these are fixed nozzles because we have

two BE cores on the liquid core.

So that's enough control authority to get us all our pitch, yah, and roll.

[D] Really? [T] Yeah.

[D] Okay. So that's unique, isn't it?

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.

But for these, we don't need that.

We got plenty of control authority on the liquid engines.

[D] Okay.

So weaseled dad in here with me to do the B roll, right?

Oh, yeah. Can you see the rocket?

That's cool. I can see it.

I think it's hard hat time. [DAD] Okay.

Got you. [D] Can you tighten in the back?

[DAD] I got it. [D] You got it?

[DAD] All right. [T] All right.

I got to get in a picture of your dad. Okay.

[D] Let's do that.

[T] You work James Webb, right? [DAD] I did, yes sir.

[T] Outstanding.

[D] You can hold the camera down, dad. [DAD] Okay.

[D] One, two, three.

That's great.

[T] So you remember the gray part here?

That's the MLP or mobile launch platform.

You can see the four sets of rails. [D] There's rails here.

[T] Yeah.

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.

[D] Well, is it pressurized?

[T] Only the upper stage.

[D] The SENTAR is pressurized right now? [T] Right.

Yeah. It has to be at all.

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.

So it's a balloon tank.

The first stage is rigid.

That's that ortho-grid, the rigid aluminum structure, the 2000-series

structure you saw in the factory. So that's okay.

But the upper stage has to be pressurized.

And all of this was in the VIF behind you.

The doors are closed right now.

Yeah, right there.

Ula on the top.

That's where we assembled all of this because it's too big

to ship this way from Decatur.

So the first stage, the upper stage, the payload faring, the interstage all

come separately here on the rocket ship.

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] Go into the moon. [T] Go into the moon.

[D] Which is cool. [T] Super cool.

[D] That's awesome. [T] And then that gets stacked.

It's all on top of the mobile launch platform.

So when it's all done, doors open, then it rolls out here at a blistering

two and a half miles per hour. [D] That's fun.

[T] Takes a couple of hours to do it because we come real slow to

clear the building, and then we take off.

We're being careful.

Somebody asked me the other day, they go, how long does it take to

roll from the vif to the pad?

And I said, oh, about eight years.

Eight years?

[D] Yeah, it's a lot of time went into that, isn't it?

[T] It was, yeah. Yeah.

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.

That's air conditioning.

That's for the payload.

Temperature, humidity, stuff like that.

Certain payloads, especially optical ones, you got to keep them super duper dry.

And then below that, as you're going down, you've got

umbilicals for the propellants.

You've got umbilicals for all the electrical systems and the data and

the power until we go to internal power.

And then, of course, up there in the middle, you got a ground wind damper

because it's a 20-story building.

[D] That's a mechanical coupling there. Okay.

[T] Because winds can get pretty high out here.

[D] Today, it's supposed to. [T] We don't want the rocket to sway.

[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.

[D] We're like 30 something hours out. Okay.

[T] So that's ground wind damper.

And then above that was all propellant and power and electricity and data.

[D] I see.

[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

swing away when it's time to launch.

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

that we do on a Delta IV heavy.

[D] How close can we go here?

[T] We're going to go until somebody stops us.

[D] We're going to go until somebody stops us. I like it.

All right, I'm switching back to wide angle.

All right.

[T] So you remember the water suppression system?

[D] Yes. That's for for acoustics, correct?

[T] For acoustics.

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

worth in the first minute here. [D] Okay.

[T] And that's all about the acoustic energy that would come out of the Rockets,

exhausted and reflect off the ground.

Water is almost the best, you know, acoustic energy absorbing

material you can have. Okay.

And the reason that's important is because where we're standing right now,

we'd be pushing 300 decibels.

So if the fire didn't get us, the sound alone would just kill us right here.

[D] Shake us apart. [T] Shake us apart.

We get massive brain hemorrhage, that stuff.

But more importantly...

Yeah, more importantly.

Without all of that absorption, that energy would reflect right back on the

rocket and likely damage the spacecraft. [D] Okay.

[T] That's what it's really about.

[D] Can I walk over here to this side?

[T] Yeah.

[D] We're in a place right now. That's amazing.

[T] Yes, we are. That rigid platform will go away.

This on the bottom goes away. Yes.

That grading you see, that goes away.

And beneath us is the flame trench. [D] Okay.

[T] And if you look to your right, that's the outlet to the flame trench right there.

[D] All the fire goes that way. [T] Yeah.

And out of that thing and It blows the lawn, knocks the fence over.

But it's florida, so the lawn will be back five minutes later.

[D] Sounds great.

[T] And so you can...

Those are the two BE4 engines.

We're going to get about a million and a half pounds of thrust out of those.

[D] Wow. They're grounded right now.

Grounded, All right, let me switch to my tighter lens.

Okay, so GEM 63s, they're canted. [T] Gem 63, XL.

[D] They're canted out.

[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.

That core will be empty.

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.

I was surprised to find out that these solids are fixed and canted

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.

But they don't do that on the Vulcan, and why is pretty interesting.

Look back at the bottom of the rocket.

Those two silver things right in the middle, those are the BE4 liquid

engines, oxygen and methane.

If we think about what's going on here, you can actually move those.

They have thrust vector control on the liquid engines.

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.

I'm going to shoot at you.

You can also do things like this.

I mean, it's hard to describe, but you can see what I'm doing.

You can even roll the vehicle by how you swing these bells

around, which is fascinating.

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

up the liquid, you load up the solid.

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.

So the CG is about here.

But as you start burning and dumping mass out the back,

the CG is going to slowly walk forward. That's fascinating.

And so you would think, okay, well, if I'm a design engineer

designing the system, I'm just going average out and shoot the middle of where

the CG starts and where the CG ends.

And that's where I'm going to thrust my solid rocket boosters through.

And the reason they do that is because they don't want

to overpower, so to speak, those liquid engines in the middle.

If you are pushing through the CG of the vehicle, you're not trying to twist

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.

So that's how they do that. I think that's very clever.

The fact that they canted that by the way, means if you have, let's say it's

three degrees on the solids.

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.

And it's even more when you have six boosters on the outside of the volcan.

I'm sorry, I'm geeking out right now, but this is a very complicated problem,

and it's very interesting.

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

twist the vehicle a certain amount.

But when you get up five miles in the atmosphere, you've got less mass

and you have less aerodynamic pressure.

So that same cantover of the nozzles, you're going to get a much different

response to the vehicle up at altitude.

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

through, which I think is fascinating.

It's a very simple, elegant solution to make these solids

just a fixed nozzle at a certain angle.

And it almost makes me empathize with the challenge that the guidance

and control engineers have trying to figure out this control algorithm.

But we're not going to do that because those are guidance and control people.

And everybody knows that solid propulsion and liquid propulsion

people, that's where it's at.

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.

[T] And so we'll get about 450,000 pounds of thrust out of each

of those solids, plus the 1.1 million from the combined pair of BE4s.

So this rocket, it'll weigh just under a million and a half pounds,

fully fueled at lift off.

We'll have about 2 million pounds of thrust, so it's not going to leap off

like if it had six solids.

So you'll see it gently come off the pad and go.

[D] Six solids, that's the maximum bulk and handle.

[T] That's the max, yeah.

[D] Is that just a structural limit or just physical positioning?

[T] It's physical space around the rocket.

But obviously, the structure is designed for that because

we knew that's what it would be.

You don't want to waste any mass with extra structure.

[D] Let me ask you about the BE4s.

I know you wanted those things forever.

It took a long time to get them to you. [T] It did.

[D] You're excited you got them, right? [T] Excited we got them.

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

with this question, Tory.

My understanding is those things in testing, they've got a lot

of horizontal firing time, but they don't have a lot of vertical.

My understanding is one or two of them has four seconds

of vertical thrust time, right? Real quick.

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

and you measure thrust and pressures and flow rates and all that stuff.

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.

Typically, you want to do that because that's how the rocket is going to fly.

[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

so much propelling through that thing.

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,

73,000 gallons of methane.

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

really aren't a driving factor at all.