RD-120
| Country of origin | USSR/Russia |
|---|---|
| Designer | NPO Energomash, V.K.Chvanov, V.P. Radovsky |
| Manufacturer | Yuzhmash |
| Application | Upper stage |
| Status | Operational |
| Liquid-fuel engine | |
| Propellant | LOX / RP-1 |
| Cycle | Staged combustion cycle |
| Performance | |
| Thrust, vacuum | Standard: 834 kN (187,000 lbf) Uprated: 912 kN (205,000 lbf) |
| Thrust-to-weight ratio | Standard: 75.55 Uprated: 82.66 |
| Chamber pressure | Standard: 162.8 bar (16.28 MPa) Uprated: 178.1 bar (17.81 MPa) |
| Specific impulse, vacuum | 350 s (3.4 km/s) |
| Burn time | 315 seconds |
| Dimensions | |
| Length | 3.87 m (12.7 ft) |
| Diameter | 1.95 m (6.4 ft) |
| Dry mass | 1,125 kg (2,480 lb) |
| Used in | |
| Zenit-2, Zenit-3SL | |
| References | |
| References | |
The RD-120 (Russian: Ракетный Двигатель-120, romanized: Raketnyy Dvigatel-120, lit. 'Rocket Engine 120', GRAU index: 11D123) is a liquid upper stage rocket engine burning RG-1 (refined kerosene) and LOX in an oxidizer rich staged combustion cycle with an O/F ratio of 2.6. It is used in the second stage of the Zenit family of launch vehicles. It has a single, fixed combustion chamber and thus on the Zenit it is paired with the RD-8 vernier engine. The engine was developed from 1976 to 1985 by NPO Energomash with V.P. Radovsky leading the development. It is manufactured by, among others, Yuzhmash in Ukraine.
It should not be confused with the RD-0120, which is a discontinued LOX/hydrogen rocket engine that was used in the Soviet Energia launch system.