Rockets/Missiles are use (mainly!) solid fuel and it’s easier/cheaper to stick a few fins on the side to steer the rocket. The rocket is light enough for the fins to change the direction of travel quickly and easily.
Larger Solid Rocket Motors (that are strapped to Space Rockets) use a nozzle that can be moved, There is usually too much mass in a rocket for steering fins to be useful. Also another method is changing the concentration of fuel at certain points inside the rocket so it burns hotter or cooler at certain points BUT can only be used on a predetermined trajectory (i.e. from the ground into a specific orbit.
Modern Space Rockets use Liquid Fuels and it’s easier to have some or all of the rocket motors on a gimble to steer the ship as it flies.
Latest Answers