Improved Orion engine

Aerojet solid rocket engine, originally designed for the Improved Hawk surface-to-air missile. Surplus motors were used in sounding rockets.

The Improved Orion motor was a bi-phase propellant system that results in thrust levels of approximately 84.5 kN during the first four seconds of motor burn then trailing off to approximately 13.3 kN until burnout around 25 seconds. The fins were generally configured to provide a burn out spin rate of four cycles per second.