Ammonium perchlorate

The primary use of ammonium perchlorate is in making solid fuel propellants. When AP is mixed with a fuel like a powdered aluminium and/or with an elastomeric binder, it can generate self-sustained combustion at far under atmospheric pressure. It is an important oxidizer with a decades-long history of use in solid rocket propellants space launch including the Space Shuttle Solid Rocket Booster, military, amateur, and hobby high-power rockets, as well as in some fireworks.

Explosives, Propellants, Detonators - ATF Regulated Explosive Materials