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. In front of me is an F-18, which is a beautiful aircraft. It can be configured for either an attack role or a fighter role. I want to show you something really cool over here. You can see all the different weapons on the pylons, and there are some bombs over there.
Look at this! (Pausing to take it in…) This is a Sidewinder missile, which changed a lot of things in a lot of places. This is one of the first heat-seeking missiles developed here in the 50s, right here at China Lake.
Let’s look at it. You can see the seeker up here, so it can go towards the exhaust of an aircraft. There are some kind of pivoting fins right here, and then you can see this side-looking proximity sensor, which is amazing that it’s on this model. This is a warhead, and we’ll talk more about the warhead in a minute. You can also see the rocket.
Look at this! (Pausing to take it in…) You can see that there’s something that looks like a water wheel here. Oh, it spins! This is called a rolleron. If you can imagine this aircraft flying along super-fast, you shoot this missile at Mach 2.5. You want to stabilize it, so you don’t want it to just spin and roll. This is a genius way to get around that. A rolleron provides dynamic stability, so as you fire the missile and it spins up, you get a flywheel effect and it becomes a giant gyroscope. That angular momentum gives you an angular momentum vector, and you can see there are four of them.
If you look closely, you’ll notice there are little bitty divots drilled out, where they balanced it because this could spin at over a 100,000 RPM. So they had to spin it up and balance it like you’d balance a tire by removing material.
This is an amazing piece of engineering. There’s a newer version of this missile, the AIM-9M. This one doesn’t have pivoting blades up front, it’s fixed here. You can see the seeker, warhead, rocket, and brown stripe for the rocket. I was perhaps too excited while opening this Sidewinder missile fin, but it doesn’t matter because it actually works! The fins pivot in the back, which is an indication of thrust vector control. It doesn’t have rollerons, but rollerons are a genius solution to a difficult problem. The warhead section is a expanding-rod warhead, which scissor out to create a cutter that is orthogonal to the direction of flight - a really bad day for an engine or aircraft.
Thanks to everyone who supports on Patreon, I was able to buy some missile parts and even found my own rolleron Sidewinder missile fin. I have an idea what to do with it, so 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!