AKA: Retropack. Status: Operational 1960. Thrust: 15.47 kN (3,479 lbf). Gross mass: 237 kg (522 lb). Unfuelled mass: 177 kg (390 lb). Specific impulse: 230 s. Height: 0.52 m (1.70 ft). Diameter: 1.04 m (3.41 ft).