RD-855
| Country of origin | Soviet Union |
|---|---|
| First flight | December 16, 1965 |
| Last flight | January 30, 2009 |
| Designer | Yuzhnoye Design Bureau |
| Manufacturer | Yuzhmash |
| Application | Vernier |
| Associated L/V | R-36, Tsyklon-2 and Tsyklon-3 |
| Status | Out of production |
| Liquid-fuel engine | |
| Propellant | N2O4 / UDMH |
| Mixture ratio | 1.97 |
| Cycle | Gas Generator |
| Configuration | |
| Chamber | 4 |
| Performance | |
| Thrust (vac.) | 328 kN (74,000 lbf) |
| Thrust (SL) | 285.4 kN (64,200 lbf) |
| Chamber pressure | 6.570 MPa (952.9 psi) |
| Isp (vac.) | 292 s (2.86 km/s) |
| Isp (SL) | 254 s (2.49 km/s) |
| Burn time | up to 127s |
| Restarts | 1 |
| Gimbal range | +/- 41° |
| Dimensions | |
| Length | 1.74 m (5 ft 9 in) |
| Diameter | 3.81 m (12.5 ft) |
| Dry weight | 320 kg (710 lb) |
| Used in | |
| R-36, Tsyklon-2 and Tsyklon-3 first stage vernier | |
| References | |
| References | [1][2][3] |
The RD-855 (GRAU Index 8D68M), also known as the RD-68M, is a four nozzle liquid rocket vernier engine, burning N2O4 and UDMH in a gas generator cycle.[3] It was used on the R-36, Tsyklon-2 and Tsyklon-3 first stage as thrust vector control by gimbaling of its nozzle.[3] The engine is distributed through a cylindrical structure that is integrated around the main engine RD-251 module. The structure includes aerodynamic protection for the nozzles and small retro engines to assure the separation of the first stage.[2] The engine was ignited two second before the RD-251 main engine.[2]
The engine was serially produced between 1965 and 1992. It was first launched on December 16, 1965 on an R-36 and its last launch was on January 30, 2009 with the last launch of the Tsyklon-3. The production capability was restarted for the Tsyklon-4 but with the apparent cancellation of the program the engine would still be out of production.[4]
See also
- R-36 – The Soviet ICBM for which the RD-855 was created.
- Tsyklon-2 – A Soviet small rocket that uses the RD-855.
- Tsyklon-3 – A Soviet small rocket that uses the RD-855.
- Tsyklon-4 – An Ukrainian small rocket project that would have used the RD-855.
- Yuzhnoe Design Bureau – The RD-855 designer bureau.
References
- ↑ "RD-855". Encyclopedia Astronautica. Retrieved 2016-07-06.
- 1 2 3 Pillet, Nicolas. "Tsiklone - Le premier étage" [Tsyklon - The first stage] (in French). Kosmonavtika.com. Retrieved 2016-07-06.
- 1 2 3 "RD-855". Yuzhnoye. Retrieved 2016-07-06.
- ↑ Krebs, Gunter Dirk (2016-04-24). "Tsiklon". Gunter's Space Page. Retrieved 2016-07-05.
