S139 Booster
| Manufacturer | Satish Dhawan Space Centre |
|---|---|
| Country of origin | India |
| Used on | GSLV and PSLV |
| General characteristics | |
| Height | 20m-PSLV 20.2m-GSLV |
| Diameter | 2.8m |
| Propellant mass | 138,200 kg 138.2 metric tonnes |
| Empty mass | 30,200 kg (66,600 lb). |
| Launch history | |
| Status | Active |
| First flight | Sep 20, 1993 |
| S139 | |
| Maximum thrust | 4,846.9 kN (1,089,600 lbf) |
| Specific impulse | 237 s (2.32 km/s) (sea level) 269 s (2.64 km/s) (vacuum) |
| Burn time | 110 seconds (PSLV) 100 seconds (GSLV) |
| Propellant | HTPB |
The S139 (S for Solid, 139 for weight of 139 tonnes) is a Solid Rocket Booster manufactured by the Indian Space Research Organisation at the Satish Dhawan Space Centre in the SPROB facility. The rocket motor was first developed for use in the Polar Satellite Launch Vehicle. Later it was utilised in the GSLV MKII. It uses hydroxyl-terminated polybutadiene (HTPB) as a propellant. It has a maximum thrust of 4800 kN.