RD-253
Mock-up of a RD-275 rocket motor at the Paris Air Show in 2013 | |
| Country of origin | Soviet Union Russia |
|---|---|
| First flight | RD-253: 1965 RD-275: 1995 RD-275М: 2007 |
| Designer | NPO Energomash, Valentin Glushko |
| Manufacturer | Proton-PM |
| Application | First stage booster |
| Associated LV | Proton |
| Successor | RD-254, RD-256, RD-275, RD-275М |
| Status | Operational |
| Liquid-fuel engine | |
| Propellant | N2O4 / UDMH |
| Mixture ratio | 2.67 |
| Cycle | Staged combustion |
| Configuration | |
| Chamber | 1 |
| Nozzle ratio | 26.2 |
| Performance | |
| Thrust, vacuum | RD-253: 1,630 kN (370,000 lbf) RD-275: 1,750 kN (390,000 lbf) RD-275М: 1,832 kN (412,000 lbf) |
| Thrust, sea-level | RD-253: 1,470 kN (330,000 lbf) RD-275: 1,590 kN (360,000 lbf) RD-275М: 1,671 kN (376,000 lbf) |
| Thrust-to-weight ratio | 156.2 |
| Chamber pressure | RD-253: 14.7 MPa (2,130 psi; 147 bar) RD-275: 15.7 MPa (2,280 psi; 157 bar) RD-275M: 16.5 MPa (2,390 psi; 165 bar) |
| Specific impulse, vacuum | RD-253: 316s RD-275: 316s RD-275M: 315.8s |
| Specific impulse, sea-level | RD-253: 285s RD-275: 287s RD-275M: 288s |
| Gimbal range | 7.5°, single plane |
| Dimensions | |
| Length | 3 m (9.8 ft) |
| Diameter | 1.5 m (4 ft 11 in) |
| Dry mass | RD-253: 1,080 kg (2,380 lb) RD-275: 1,070 kg (2,360 lb) RD-275M: 1,070 kg (2,360 lb) |
| References | |
| References | |
The RD-253 (Russian: Ракетный Двигатель-253, romanized: Raketnyy Dvigatel-253, lit. 'Rocket Engine 253') and its later variants, the RD-275 and RD-275M, are liquid-propellant rocket engines developed in the Soviet Union by Energomash. The engines are used on the first stage of the Proton launch vehicle and use an oxidizer-rich staged combustion cycle to power the turbopumps. The engine burns a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide (N2O4) oxidizer, which are highly toxic, but storable at room temperature.