Fregat
Model of Fregat at MAKS Airshow, 2013 | |
| Manufacturer | NPO Lavochkin |
|---|---|
| Country of origin | Russia |
| Used on | Current: Soyuz-2 Retired: Soyuz-FG, Soyuz-ST, Soyuz-U, Zenit-3F |
| Launch history | |
| Status | Active |
| Total launches | 114 |
| Successes (stage only) | 111 |
| Failed | 2 |
| Other | 1 (partial failure) |
| First flight | 2 February 2000 |
| General characteristics | |
| Height | Fregat: 1.875 m (6 ft 1.8 in) Fregat-MT: 1.945 m (6 ft 4.6 in) Fregat-SB: 2.435 m (7 ft 11.9 in) |
| Diameter | Fregat: 3.44 m (11.3 ft) Fregat-MT: 3.8 m (12 ft) Fregat-SB: 3.875 m (12.71 ft) |
| Empty mass | Fregat: 945 kg (2,083 lb) Fregat-MT: 1,035 kg (2,282 lb) Fregat-SB: 1,080 kg (2,380 lb) |
| Gross mass | Fregat: 6,235 kg (13,746 lb) Fregat-MT: 7,640 kg (16,840 lb) Fregat-SB: 11,680 kg (25,750 lb) |
| Propellant mass | Fregat: 5,307 kg (11,700 lb) Fregat-MT: 6,650 kg (14,660 lb) Fregat-SB: 10,330 kg (22,770 lb) |
| Powered by | 1 × S5.92 |
| Maximum thrust | 19.85 kN (4,460 lbf) (high) 13.93 kN (3,130 lbf) (low) |
| Specific impulse | 333.2 s (3.268 km/s) (high) 320 s (3.1 km/s) (low) |
| Burn time | Up to 1,350 seconds (up to 7 starts) |
| Propellant | N2O4/UDMH |
Fregat (Russian: Фрегат, lit. 'frigate') is an upper stage developed by NPO Lavochkin for universal compatibility with a wide range of medium- and heavy-lift launch vehicles. Fregat has been used primarily with Soyuz and Zenit rockets, and entered operational service in February 2000.
Fregat uses a liquid-propellant engine burning unsymmetrical dimethylhydrazine (UDMH) fuel and dinitrogen tetroxide (N2O4) oxidizer, a pair of hypergolic propellants that ignite on contact. With a success rate of 97.3%, including two failures and one partial failure, Fregat is among the most reliable upper stages in operation. It has deployed more than 300 payloads into a variety of orbits and is capable of placing three or more spacecraft into distinct orbits during a single mission, owing to its ability to restart up to seven times and operate for a total burn duration of up to 1,350 seconds.