Long March 3B
The launch of a Long March 3B carrier rocket at Xichang Satellite Launch Center.
|Function||GTO Carrier rocket|
|Country of origin||China|
|Height||3B: 54.838 metres (179.91 ft)
3B/E: 56.326 metres (184.80 ft)
|Diameter||3.35 metres (11.0 ft)|
|Mass||3B: 425,800 kilograms (939,000 lb)
3B/E: 458,970 kilograms (1,011,900 lb)
|12,000 kilograms (26,000 lb)|
|5,700 kilograms (13,000 lb)|
|3B: 5,100 kilograms (11,000 lb)
3B/E: 5,500 kilograms (12,000 lb)
|2,000 kilograms (4,400 lb)|
|3,300 kilograms (7,300 lb)|
|Derivatives||Long March 3C|
|Launch sites||LC-2, XSLC|
|Total launches||3B: 10
|Partial failures||3B: 1|
|First flight||3B: 14 February 1996
3B/E: 13 May 2007
|Boosters (Stage 0)|
|Specific impulse||(2556.2 N-s/kg)|
|Specific impulse||(2556.2 N-s/kg)|
|Thrust||742 KN (Main)
11.8×4 KN (Vernier)
|Specific impulse||2922.57 N-s/kg (Main)
2910.5 N-s/kg (Vernier)
|Specific impulse||(4312 N-s/kg)|
The Long March 3B (Chinese: 长征三号乙火箭, Chang Zheng 3B), also known as the 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 in Sichuan. A three-stage rocket with four strap-on liquid rocket boosters, it is currently the 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, the Long March 3B was the second-most-capable expendable launch system in the world, after the Russian Proton. An enhanced version, the Long March 3B/E, was introduced in 2007 to increase the rocket's GTO cargo capacity and lift heavier GEO communications satellites. As of March 2013, the Long March 3B and 3B/E have conducted 21 successful launches, with three others ending in partial or complete failure. The Long March 3B was the basis for the medium-capacity Long March 3C, which was first launched in 2008.
The development of the Long March 3B began in 1986 to meet the needs of the international GEO communications satellite market. During its maiden flight on 14 February 1996 carrying the Intelsat 708 satellite, the rocket suffered a guidance failure two seconds into the flight and crashed into a nearby village, killing at least six people. The Long March 3B and 3B/E rockets conducted ten successful launches between 1997 and 2008. In 2009, a Long March 3B partially failed during launch due to a third stage anomaly, which resulted in the Palapa-D satellite reaching a lower orbit than planned. Nonetheless, the satellite was able to maneuver itself into the planned orbit. The Long March 3B and its variants remain in active use as of March 2013[update], having conducted a total of 21 successful launches.
Design and variants 
The Long March 3B is based on the Long March 3A as its core stage, with four liquid boosters strapped on the first stage. It has an LEO cargo capacity of 12,000 kilograms (26,000 lb) and a GTO capacity is 5,100 kilograms (11,000 lb).
Long March 3B/E 
The Long March 3B/E is an enhanced variant of the Long March 3B, featuring an enlarged first stage and boosters, increasing its GTO payload capacity to 5,500 kilograms (12,000 lb). Its maiden flight took place on 13 May 2007, when it successfully launched NigComSat-1, the first African geosynchronous communications satellite.
Long March 3C 
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 has two boosters instead of four, giving it a reduced GTO payload capacity of 3,800 kilograms (8,400 lb). Its maiden launch took place on 25 April 2008.
Launch failures 
On February 14, 1996 a Long March-3B rocket failed during launch. The vehicle pitched over immediately after liftoff, impacting and exploding at T+22 s near a village close to the launch site. At least six people were killed. The fault was traced to a lack of output from the power module for the servo-loop in the follow-up frame of the inertial platform. This caused a faulty inertial reference, which made the launch vehicle steer incorrectly.
Agila 2 
Spacecraft had to use onboard propellant to reach correct orbit because of poor injection accuracy on the part of launch vehicle.
|This section requires expansion. (May 2013)|
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