Hey, it’s me Destin, welcome back to Smarter Every Day. I want to talk about something really neat. I’m at Naval Air Weapons Station China Lake here in California. I’m in front of a building that does things and here is an F-18 – a beautiful bird. This particular aircraft can be configured for the attack role or for a fighter role and there’s something I want to show you that’s way over here. Check this out. You know all the different weapons on the pylons? Got some bombs over there. Look at this. (Pausing to take it in…) This is a Sidewinder missile and this changed a lot of things in a lot of places. This is one of the first heat-seeking missiles that was developed here in the 50s right here at China Lake.
Let’s look at it. So you got a seeker up here so it can go towards the exhaust of an aircraft. You’ve got some kind of pivoting fins right here. Look right here, you’ve got this – is a side looking proximity sensor which is amazing that that’s on this model. This is a warhead, we’ll talk more about the warhead in a minute. You got the rocket. And then you get these things in the back. Look at this – so I want to talk about this. If you look closely, you’ll notice there’s something that looks like a water wheel here. You see that? Oh, it spins! Look at that! So this is called a rolleron.
Now, if you can imagine this aircraft is flying along super super fast, you shoot this missile at Mach 2.5. You want to stabilize it, right? You don’t want it to just spin and roll, so you’ve got roll, pitch, and yaw, right? You don’t want this thing to roll in ways that you don’t want it to, so this is a genius way to get around that. A rolleron, oh look! You can see right there – you see those little bitty divots? You gotta look close, see those little things that are drilled out there? That’s where they balanced it because this could spin at over a 100,000 RPM and so they had to make some weigh more or less than others so they had to like spin this thing up and balance it like you’d balance a tire by removing material. But anyway, a rolleron, what it does is as you fire the missile and this spins up, you get a flywheel effect so you get a gyroscopic effect and it becomes a giant flywheel like a gyroscope and so that angular momentum gives you an angular momentum vector that’s right there and you can see there’s four of them – there’s one, there’s two, there’s three, and there’s four.
So imagine if you would, you’re about to fire this missile and if and if you have problems with dynamic stability in the roll axis because you’re an engineer in the 50s and you don’t have really fast control loops and digital circuitry at your disposal yet, this is a genius – this is just genius! Because it’s a passive dynamic stability method. So imagine you could pin a vector here, pin a vector here, here, and there, and just kind of lock it in space so it’ll go straight. That’s amazing.
One thing I don’t understand is there appears to be a pivot point here? So as the missile tries to roll, this thing could try to stay in position and so it’ll try to stay back where it was and I assume that would also provide some aerodynamic stability passively? I… I don’t know, I don’t know how that works, but I think it’s fascinating. So I think it’s an amazing piece of engineering.
There’s a newer missile, a newer version over here – that’s the AIM-9M, I think the first one… (Trying to remember) I read it on a thing. Is it on this? Okay, so the first one… so that one over there was the M, the B was the first one they deployed. This one is the X, this is the AIM-9X. So this one right here is uh… if I can focus on it, let’s see if I can focus up close here. So you’ll notice it’s different! It doesn’t have pivoting blades up front, it’s fixed here. So we’ve got a seeker – that’s good. Let’s move back. Don’t have a proximity fuse here, it’s got this kind of billet here, warhead, rocket, brown stripe for rocket. Check out this amazing Sidewinder missile fin! It’s different than the 9-Mike over there, and you can see anytime you have something in the rocket plume itself, that’s usually an indication of thrust vector control. I’ve never worked with this system, but I hear it’s amazing. It doesn’t have rollerons, but they’re a genius solution to a difficult problem.
The warhead section has an expanding-rod warhead. It has rods stacked up in a cylinder around it, and when detonated, it would scissor out and create a cutter that’s orthogonal to the direction of flight. It’s designed to damage the engine of an aircraft.
I found my own rolleron Sidewinder missile fin on the internet and it actually works! Thanks to everyone who supports on Patreon, I was able to buy some missile parts. It’s so cool! Feel free to subscribe if you want to see what I do with it. I’m Destin, you’re getting Smarter Every Day. Have a good one!