FSW Retromotor

Fourth Academy solid rocket engine. In Production. Retrorocket designed for deorbit of FSW recoverable satellite. First flight 1975.

New technologies introduced included steel/titanium alloy spherical chamber case; arc umbrella finocyl grain mandrel design; new propellant casting processes; and aft end ignition in vacuum conditions. The motor had to fire after 8 to 15 days in orbit, at spin rates of 60 rads/minute. During the lifetime of the spacecraft series several variants of the motor were developed, first using CTPB, and later HTPB propellant. The motor performed without fail 15 times on 15 flights. Total impulse 582.5 kN-s over 18.5 seconds.

Propellant Formulation: HTPB.