Abstract: The apogee boost motor (ABM) for the STW experimental communications satellite is a solid composite propellant rocket motor. Its case is a glass/epoxy filament wound composite structure. Its pro pliant is of HTPB type. The materialof its nozzle throat is carbon/carbon composite, and the exit cone is wound by a highly silica-filled phenolic/glass tape. Its ignition system consists of ignitor and safe and arm device. A series of motor tests have proved that the ABM has high reliability and performance accuracy. The reliability of the ABM is 0.9551 with the confidence being 0.8.This work predicts and analyses the potential accidents of the ABM during space-flight, and proposes various approaches to eliminate them. The calculationsbased on the parameters gathered before and after space flight show that the total impulse is 1258.3 kN·s and the specific impulse is 2834.1 N·s/kg. Both of them are in good agreement with those from ground-firing tests with a variation of the total impulse within the range of ±1%. It is shown that the ground-firing tests are accurate and efficient.