Long March 3B

Rendering of Long March 3B
Function	Launch vehicle
Manufacturer	China Academy of Launch Vehicle Technology (CALT)
Country of origin	China
Cost per launch	US$50-70 million [1][2][3]
Size
Height	3B: 54.8 m (180 ft) [4] 3B/E: 56.3 m (185 ft) [5]
Diameter	3.35 m (11.0 ft) [4]
Mass	3B: 425,800 kg (938,700 lb) 3B/E: 458,970 kg (1,011,860 lb) [5]
Stages	3 / 4
Capacity
Payload to LEO
Mass	11,500 kg (25,400 lb) [6][7]
Payload to SSO
Mass	7,100 kg (15,700 lb) [6][7]
Payload to GTO
Mass	3B: 5,100 kg (11,200 lb) [6][7] 3B/E: 5,500 kg (12,100 lb) [5]
Payload to GEO
Mass	2,000 kg (4,400 lb) [7]
Payload to HCO
Mass	3,300 kg (7,300 lb) [6][7]
Associated rockets
Family	Long March
Derivative work	Long March 3C
Comparable	Atlas V Delta IV Falcon 9 (reusable) GSLV Mk III H-IIA Zenit-3F
Launch history
Status	3B: Retired (have opportunity to launch TianWen-2 in 2025) 3B/E: Active
Launch sites	Xichang LC-2, LC-3
Total launches	94 3B: 12 3B/E: 82
Success(es)	90 3B: 10 3B/E: 80
Failure(s)	2 3B: 1 (Intelsat 708) 3B/E: 1 (Palapa-N1)
Partial failure(s)	2 3B: 1 (Palapa-D) 3B/E: 1 (ChinaSat 9A)
First flight	3B: 14 February 1996 (Intelsat 708) 3B/E: 13 May 2007 (NigComSat-1)
Last flight	3B: 18 September 2012 (Compass M5, M6) 3B/E: 29 February 2024 (Weixing Hulianwang Gaogui-01)
Type of passengers/cargo	Chang'e 3, Chang'e 4, BeiDou, ChinaSat
Boosters (3B)
No. boosters	4
Height	15.33 m (50.3 ft)
Diameter	2.25 m (7 ft 5 in)
Propellant mass	37,700 kg (83,100 lb)
Powered by	1 × YF-25
Maximum thrust	740.4 kN (166,400 lbf)
Specific impulse	2,556.2 m/s (260.66 s)
Burn time	127 seconds
Propellant	N2O4 / UDMH
Boosters (3B/E)
No. boosters	4
Height	16.1 m (53 ft)
Diameter	2.25 m (7 ft 5 in)
Propellant mass	41,100 kg (90,600 lb)
Powered by	1 × YF-25
Maximum thrust	740.4 kN (166,400 lbf)
Specific impulse	2,556.2 m/s (260.66 s)
Burn time	140 seconds
Propellant	N2O4 / UDMH
First stage (3B)
Height	23.27 m (76.3 ft)
Diameter	3.35 m (11.0 ft)
Propellant mass	171,800 kg (378,800 lb)
Powered by	4 × YF-21C
Maximum thrust	2,961.6 kN (665,800 lbf)
Specific impulse	2,556.5 m/s (260.69 s)
Burn time	145 seconds
Propellant	N2O4 / UDMH
First stage (3B/E)
Height	24.76 m (81.2 ft)
Diameter	3.35 m (11.0 ft)
Propellant mass	186,200 kg (410,500 lb)
Powered by	4 × YF-21C
Maximum thrust	2,961.6 kN (665,800 lbf)
Specific impulse	2,556.5 m/s (260.69 s)
Burn time	158 seconds
Propellant	N2O4 / UDMH
Second stage
Height	12.92 m (42.4 ft)
Diameter	3.35 m (11.0 ft)
Propellant mass	49,400 kg (108,900 lb)
Powered by	1 × YF-24E YF-22E (Main) YF-23F (Vernier)
Maximum thrust	742 kN (167,000 lbf) (Main) 47.1 kN (10,600 lbf) (Vernier)
Specific impulse	2,922.57 m/s (9,588.5 ft/s) (Main) 2,910.5 m/s (9,549 ft/s) (Vernier)
Burn time	185 seconds
Propellant	N2O4 / UDMH
Third stage
Height	12.38 m (40.6 ft)
Diameter	3.0 m (9.8 ft)
Propellant mass	18,200 kg (40,100 lb)
Powered by	2 × YF-75
Maximum thrust	167.17 kN (37,580 lbf)
Specific impulse	4,295 m/s (438.0 s)
Burn time	478 seconds
Propellant	LH2 / LOX
Fourth stage (optional) – YZ-1
Powered by	1 × YF-50D
Maximum thrust	6.5 kN (1,500 lbf)
Specific impulse	315.5 s (3.094 km/s)
Propellant	N2O4 / UDMH
[edit on Wikidata

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 launch vehicle. Introduced in 1996, it is launched from Launch Area 2 and 3 at the Xichang Satellite Launch Center in Sichuan. A three-stage rocket with four strap-on liquid rocket boosters, it is the heaviest variant of the Long March 3 rocket family, and is mainly used to place communications satellites and navigation satellites into geosynchronous orbits.

An enhanced version, the Long March 3B/E or G2, was introduced in 2007 to increase the rocket's geostationary transfer orbit (GTO) cargo capacity and lift heavier geosynchronous orbit (GEO) communications satellites. The Long March 3B also served as the basis for the medium-capacity Long March 3C, which was first launched in 2008.

As of 29 February 2024^[update], the Long March 3B, 3B/E and 3B/G5 have conducted 90 successful launches, plus 2 failures and 2 partial failures, accumulating a success rate of 95.7%.

History

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 destroyed a nearby town, killing at least six people,^[8] but outside estimates suggest that anywhere between 200 and 500 people might have been killed.^[9] However, the author of the report^[9] later ruled out large casualties, because evidence suggest that the crash site was evacuated before the launch.^[10]

The Long March 3B and 3B/E rockets conducted ten successful launches between 1997 and 2008.^[5]

In 1997, the Agila 2 satellite was forced to use onboard propellant to reach its correct orbit because of poor injection accuracy on the part of its Long March 3B launch vehicle.^[11] 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.^[12] 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 January 2021^[update], having conducted a total of 26 consecutive successful launches, since 19 June 2017 until 9 March 2020.

In December 2013, a Long March 3B/E successfully lifted Chang'e 3, China's first Lunar lander and rover into the projected lunar-transfer orbit.

In April 2020, the third stage of the Long March 3B/E failed during a Palapa-N1 communications satellite mission; this was the first total failure of the Long March 3B/E.^[13]

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 a low Earth orbit (LEO) cargo capacity of 11,200 kg (24,700 lb) and a GTO capacity is 5,100 kg (11,200 lb).

Long March 3B/E

The Long March 3B/E, also known as 3B/G2, is an enhanced variant of the Long March 3B, featuring an enlarged first stage and boosters, increasing its GTO payload capacity to 5,500 kg (12,100 lb).^[14] Its maiden flight took place on 13 May 2007, when it successfully launched Nigeria's NigComSat-1, the first African geosynchronous communications satellite. In 2013, it successfully launched China's first lunar lander Chang'e 3 and lunar rover Yutu.

Since 2015, the Long March 3B and 3C can optionally accommodate a YZ-1 upper stage, which has been used to carry dual launches or BeiDou navigation satellites into medium Earth orbit (MEO).

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 kg (8,400 lb). Its maiden launch took place on 25 April 2008.

Launch statistics

List of launches