The launch of a Long March 3B carrier rocket at Xichang Satellite Launch Center |
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| Function | GTO Carrier rocket |
|---|---|
| Manufacturer | CALT |
| Country of origin | People's Republic of China |
| Size | |
| Height | 3B: 54.838 metres (179.91 ft)[1] 3B/E: 56.326 metres (184.80 ft)[2] |
| Diameter | 3.35 metres (11.0 ft)[1] |
| Mass | 3B: 425,800 kilograms (939,000 lb)[1] 3B/E: 458,970 kilograms (1,011,900 lb)[2] |
| Stages | 3 |
| Capacity | |
| Payload to LEO |
12,000 kilograms (26,000 lb)[3] |
| Payload to SSO |
5,700 kilograms (13,000 lb)[3] |
| Payload to GTO |
3B: 5,100 kilograms (11,000 lb)[3] 3B/E: 5,500 kilograms (12,000 lb)[2] |
| Payload to GEO |
2,000 kilograms (4,400 lb)[3] |
| Payload to HCO |
3,300 kilograms (7,300 lb)[3] |
| Associated rockets | |
| Family | Long March |
| Derivatives | Long March 3C |
| Launch history | |
| Status | Active |
| Launch sites | LC-2, XSLC |
| Total launches | 3B: 10 3B/E: 8 |
| Successes | 3B: 8 3B/E: 8 |
| Failures | 3B: 1 |
| Partial failures | 3B: 1 |
| Maiden flight | 3B: 14 February 1996 3B/E: 13 May 2007 |
| Boosters (Stage 0) | |
| No boosters | 4 |
| Length | 15.326 m |
| Diameter | 2.25 m |
| Engines | YF-25 |
| Thrust | 740.4×4 KN |
| Specific impulse | (2556.2 N-s/kg) |
| Fuel | N2O4/UDMH |
| First Stage | |
| Length | 23.272 m |
| Diameter | 3.35 m |
| Engines | 4 YF-20C |
| Thrust | 2961.6 KN |
| Specific impulse | (2556.2 N-s/kg) |
| Fuel | N2O4/UDMH |
| Second Stage | |
| Length | 9.943 m |
| Diameter | 3.35 m |
| Engines | YF-24E YF-22E (Main) YF-23C (Vernier) |
| Thrust | 742 KN (Main) 11.8×4 KN (Vernier) |
| Specific impulse | 2922.57 N-s/kg (Main) 2910.5 N-s/kg (Vernier) |
| Fuel | N2O4/UDMH |
| Third Stage | |
| Length | 12.375 m |
| Diameter | 3.00 m |
| Engines | YF-75 |
| Thrust | 78.5×2 KN |
| Specific impulse | (4312 N-s/kg) |
| Fuel | LOX/LH2 |
The Long March 3B (Chinese: 长征三号乙火箭), also known as the Chang Zheng 3B, CZ-3B and LM-3B, is a Chinese orbital carrier rocket. Introduced in 1996, it is launched from Launch Area 2 at the Xichang Satellite Launch Centre. A three-stage rocket with four strap-on liquid rocket boosters, it is most powerful member of the Long March rocket family and the heaviest of the Long March 3 rocket family, and is mainly used to place communications satellites into geosynchronous orbits. At the time of its introduction, it was the second most capable expendable launch system in the world, only after the Russian Proton.[4] An enhanced version, the Long March 3B/E was developed to increase GTO capacity and lift heavier GEO communications satellites.
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The development of the Long March 3B was started in 1986 on the basis of the prior technology of Long March launch vehicles to meet the demand of international GEO communications satellite market, especially for high power and heavy communications satellites. During its maiden flight on 14 February 1996, the rocket suffered a guidance failure two seconds into the flight and pitched over, crashing into a nearby village 22 seconds after launch. The Intelsat 708 satellite was lost and as many as 100 villagers were killed. Following its maiden flight, the next ten launches of Long March 3B and 3B/E rockets were successful. In 2009, a Long March 3B partially failed during the launch due to a third stage anomaly which resulted in Palapa-D reaching a lower than planned orbit.[5] However, the satellite was able to maneuver itself into the planned orbit.
The Long March 3B is the most powerful launch vehicle in Long March fleet and is based on the Long March 3A as its core stage with four liquid boosters strapped on the first stage. Its LEO capacity is 12,000 kilograms (26,000 lb) and GTO capacity is 5,100 kilograms (11,000 lb). It has been launched nine times so far.
The Long March 3B/E is an enhanced Long March 3B, which features an enlarged first stage and boosters, which increase its GTO payload capacity to 5,500 kilograms (12,000 lb).[6] Its maiden flight was on 13 May 2007, when it successfully launched NigComSat-1, the first African geosynchronous communications satellite. It was also used for launching Venesat-1 in 2008. In 2011, it successfully launched the Pakistani communication satellite Paksat-1R.
A modified version of the Long March 3B, the Long March 3C, was developed in the mid-1990s to bridge the gap in payload capacity between the Long March 3B and 3A. It is almost identical to the Long March 3B but with two boosters instead of four, which results in a reduced GTO payload capacity of 3,800 kilograms (8,400 lb). Its first launch was on 25 April 2008. [4]
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