Engine Model: SRM-1. Manufacturer Name: Orbus 21. Designer: CSD. Gross Mass: 10,841 kg (23,900 lb). Empty Mass: 1,134 kg (2,500 lb). Propellants: Solid. Thrust(vac): 181.500 kN (40,803 lbf). Thrust(sl): 70.500 kN (15,849 lbf). Isp: 296 sec. Isp (sea level): 115 sec. Burn time: 152 sec. Diameter: 2.34 m (7.67 ft). Length: 3.15 m (10.33 ft). Chambers: 1. Chamber Pressure: 58.00 bar. Area Ratio: 64.00. Country: USA. First Flight: 1982. Last Flight: 2005. Flown: 84. Used in TOS; IUS-1 on Shuttle, Titan 34D. Known by manufacturer as Orbus 21. Propellant: 86% solids made up of HTPB UTP-19360A. Shape: cylindrical.
SRM-1 used on Rocket Stages