They have little steering vanes.
“They have little steering vanes.”
And, a little bitty doodle bug inside to work the pedals.
“They have little steering vanes.”
Surface to air missiles and some artillery projectiles have for years used gas generators to effect changes of direction. Little tiny puffs of hot gas blown out side vents in the proper direction can force the projectile to alter its course. Useful when there’s no room to mount steering vanes, or no time to deploy them.
The Gyrojet (early 1960s) used vectored thrust to spin projectiles and achieve gyro stabilization.
What’s new here would be the level of microminiaturization. Seeker or receiver (to receive commands to change course), guidance processor, servo devices and effectors have been around for decades, but making them this tiny, and this rugged (to survive acceleration of being fired from the gun barrel) has been stumping designers for some years.
Ruggedization has taken time. The US designers of the variable-time fuze (proximity fuze) during WWII had to overcome huge difficulties to make electronic components sturdy enough to be fired from a gun (remember, the 1940s was the vacuum-tube era).
USN developers are still searching for electronic components able to endure launch from a rail gun. Currently, rail gun ammunition is limited to solid metal projectiles: no mechanical parts, pyro trains, nor bursting charges can survive launch yet still function.