Rockets are unguided, explosive projectiles fired from pods. The instruments show them as RKT.
An empty pod reloads by itself. Press R to reload early, or land on a friendly aircraft carrier to rearm at once.
A rocket pod is listed like this: 2 × 29-rkt Mighty Mouse pod (6r/s 754m/s 0-7000m) [141dmg each]. That is two pods of 29 rockets each, fired at 6 rockets per second, flying at 754 meters per second with a range of up to 7000 meters, and dealing 141 damage per rocket.