Status: Study 2004. Thrust: 19.60 kN (4,406 lbf). Gross mass: 6,565 kg (14,473 lb). Unfuelled mass: 1,600 kg (3,500 lb). Specific impulse: 326 s. Height: 2.61 m (8.56 ft). Diameter: 2.50 m (8.20 ft). Span: 2.50 m (8.20 ft).
High performance storable liquid engine. Engine system consisted of: main engine (2000 kgf, Isp=325.5 s) + 4 11D458 (40 kgf, Isp=252 s) + 12 17D58E (1.36 kgf, Isp=247 s). Main engine: Derivative of S5.92. Capable of 8 restarts. Total deliverable impulse 2,000,000 kgf-s. Minimum impulse 2500 kg-s. Maximum burn time 1000 seconds; minimum time 1 second. Time between burns between 15 seconds and 5 hours. Vernier engines: 4 x 40 kgf. Specific impulse 275 sec. Total summary impulse 14,112 kg-s. Minimum impulse 4 kg-s. Orientation engines: 12 x 1.3 kgf. Specific impulse 270 sec. Minimum impulse 0.068 kg-s.