Engine Model: T-7A Booster. Manufacturer Name: Sounding Rocket Motor. Designer: Fourth Academy. Developed in: 1962-1966. Application: T-7 sounding rocket. Gross Mass: 150 kg (330 lb). Empty Mass: 33 kg (72 lb). Propellants: Solid. Thrust(vac): 46.000 kN (10,341 lbf). Isp: 209 sec. Burn time: 7.50 sec. Diameter: 0.29 m (0.94 ft). Length: 1.82 m (5.98 ft). Chambers: 1. Country: China. Status: Out of Production. First Flight: 1965. Last Flight: 1970. China's first flight solid rocket motor was this 286 mm diameter engine developed for the T-7A sounding rocket. The motor used polysulfide binder with aluminium binder. The case was of high strength steel with a graphite throat insert. Fundamental problems were solved during development of this motor, among them combustion instability and grain cracking. Flight tests began in 1965. Total impulse 238 kN-s over 7.5 seconds.
Development of solid propellant motors was begun in China in 1958. The first experimental test motor, 65 mm in diameter, was fired in 1960. First test of the 286 mm motor was in 1962.