Long March 2 rocket family or Chang Zheng 2 rocket family as in Chinese pinyin is an expendable launch system operated by the People's Republic of China. The rockets use the abbreviations LM-2 family for export, and CZ-2 family within China, as "Chang Zheng" means "Long March" in Chinese pinyin. They are part of the larger Long March rocket family. Development and design falls mostly under the auspices of the China Academy of Launch Vehicle Technology (CALT).
Long March 2 was the original model in the Long March 2 rocket family, which was derived from China's first ICBM, the DF-5. The development work began in 1970. The first rocket was launched on November 5, 1974, but the launch failed. After the failed first launch of Long March 2, its design was slightly modified and designated as Long March 2A. Long March 2A was successfully launched in 1975. The production of the Long March 2A ended in 1979.
Long March 2C and Long March 2D's first launches occurred in 1982 and 1992 respectively.
The Long March 2E was the first in the Long March rocket family to introduce liquid rocket boosters, as well as a solid rocket perigee kick stage, to improve its GTO payload capacity to satisfy the domestic and international launch market in the 1990s. It was first launched in 1992. However, the Long March 2E had problems with excessive vibration, destroying the Optus B2 and Apstar 2 satellites and damaging AsiaSat 2. After 2 failures and 1 partial failure, the Long March 2E was withdrawn from the market after just 5 years in operation.
The development of Long March 2F began in 1992 as a human-rated version of the Long March 2E. Its first launch was in November 1999 (See also Shenzhou 1). This version is the safest model in the Long March 2 family, with 11 launches and no failure record. An unmanned derivative called Long March 2F/G carries the bulkier Tiangong space laboratories.
Long March 2D and Long March 4 were developed by the Shanghai Academy of Space Flight Technology (SAST), while all others are developed by CALT.
See also: Long March 3
The designations Long March 2A and Long March 2B were originally applied to design studies of Long March 2 derivatives for geostationary payloads. Long March 2A would use a cryogenic third stage, and Long March 2B a hypergolic one. Neither design was finalized. The 2A design was adopted as the Long March 3.
(plus 4 Strap-on boosters)
(plus 4 Strap-on boosters)
|Max. diameter (m)||3.35||3.35||3.35||7.85||7.85|
|Liftoff mass (t)||190||192||232||462||464|
|Liftoff thrust (kN)||2786||2786||2962||5923||6512|
|Payload (LEO, kg)||1800||2400||3100||9200||8400|
The following launch statistics are gathered from the individual Wikipedia pages of each CZ-2x variants as those pages are updated more frequently by various editors; the numbers are current as of 29 October, 2022.
|Derivatives||Status||First flight||Launches||Successes||Failures||Partial Failures|
|Long March 2||Retired||5 November 1974||1||0||1||0|
|Long March 2A||Retired||26 November 1975||3||3||0||0|
|Long March 2C||Active||9 September 1982||65||64||1||0|
|Long March 2D||Active||9 August 1992||69||68||0||1|
|Long March 2E||Retired||16 July 1990||7||5||2||0|
|Long March 2F||Active||19 November 1999||18||18||0||0|
The principal difference between the Shenzhou-launching Long March 2F and its 2F/G cousin is easy to spot. The 2F/G carries a very different payload fairing at its top. This accounts. for the larger dimensions of the Tiangong laboratory, which wouldn't fit inside the standard payload fairing for the 2F.
It also lacks an emergency escape system. With no astronauts on board, the escape rocket and stabilizer panels that help Shenzhou spacecraft to separate from their rocket in a launch failure are not needed. This simplifies the design and also reduces the weight of the rocket. That's critical. Tiangong modules weigh more than Shenzhou spacecraft, so this helps to keep the overall launch mass within performance limits.