Proton-K
 Launch of a Proton-K carrying the Zvezda module of the International Space Station | |
| Function | Heavy-lift launch vehicle |
|---|---|
| Manufacturer | Khrunichev |
| Country of origin | Soviet Union · Russia |
| Size | |
| Height | 50 m (160 ft) |
| Diameter | 7.4 m (24 ft) |
| Stages | 3 or 4 |
| Capacity | |
| Payload to LEO | |
| Mass | 19,760 kg (43,560 lb) Record: 22,776 kg (50,212 lb) with Zvezda |
| Associated rockets | |
| Family | Universal Rocket |
| Based on | Proton |
| Derivative work | Proton-M |
| Launch history | |
| Status | Retired |
| Launch sites | Baikonur, Sites 81/23, 81/24, 200/39 & 200/40 |
| Total launches | 310 |
| Success(es) | 275 (89%) |
| Failure | 24 |
| Partial failure | 11 |
| First flight | 10 March 1967 |
| Last flight | 30 March 2012 |
| First stage | |
| Height | 21.2 m (70 ft) |
| Diameter | 7.4 m (24 ft) |
| Empty mass | 31,100 kg (68,600 lb) |
| Gross mass | 450,510 kg (993,200 lb) |
| Powered by | 6 × RD-253-14D48 |
| Maximum thrust | 10,470 kN (2,350,000 lbf) |
| Specific impulse | 316 s (3.10 km/s) |
| Burn time | 124 seconds |
| Propellant | N2O4/UDMH |
| Second stage – 8S811K | |
| Height | 14 m (46 ft) |
| Diameter | 4.15 m (13.6 ft) |
| Empty mass | 11,715 kg (25,827 lb) |
| Gross mass | 167,828 kg (369,997 lb) |
| Powered by | 4 × RD-0210 |
| Maximum thrust | 2,399 kN (539,000 lbf) |
| Specific impulse | 327 s (3.21 km/s) |
| Burn time | 206 seconds |
| Propellant | N2O4/UDMH |
| Third stage | |
| Height | 6.5 m (21 ft) |
| Diameter | 4.15 m (13.6 ft) |
| Empty mass | 4,185 kg (9,226 lb) |
| Gross mass | 50,747 kg (111,878 lb) |
| Powered by | 1 × RD-0212 |
| Maximum thrust | 613.8 kN (138,000 lbf) |
| Specific impulse | 325 s (3.19 km/s) |
| Burn time | 238 seconds |
| Propellant | N2O4/UDMH |
Proton-K (Протон-К, GRAU: 8K82K, Sheldon: D-1, D-1-e, D-1-h, DoD: SL-12, SL-13), was a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and launched from sites 81/23, 81/24, 200/39 and 200/40 at the Baikonur Cosmodrome in Kazakhstan.
The maiden flight in 1967 carried a Soyuz 7K-L1 as part of the Zond program. During the Moon Race these Proton/Zond flights consisted of several uncrewed test flights of Soyuz spacecraft to circumlunar orbits with the unrealized aim of landing Soviet cosmonauts on the Moon.
During the 1970s and 1980s, Proton-K launched every interplanetary probe of the Soviet space program's Venera and Mars missions, using its Blok D fourth stage. In three-stage configuration, it launched the Zond program's circumlunar flights and all seven space stations of the Salyut program. The Soviet program also considered the Proton for launching the TKS crewed spacecraft and LKS spaceplane.
From 1986, the rocket launched six of the seven modules of Mir, the first modular space station, and from 1998, launched the Zarya and Zvezda modules of the International Space Station's Russian Orbital Segment. It was retired from service in favour of the modernised Proton-M, making its 310th and final launch on 30 March 2012.