Long March (rocket family)

A Long March rocket (simplified Chinese: 长征系列运载火箭; traditional Chinese: 長征系列運載火箭; pinyin: Chángzhēng xìliè yùnzài huǒjiàn) or Changzheng rocket in Chinese pinyin is any rocket in a family of expendable launch systems operated by the People's Republic of China. Development and design falls under the auspices of the China Academy of Launch Vehicle Technology. In English, the rockets are abbreviated as LM- for export and CZ- within China, as "Chang Zheng" means "Long March" in Chinese pinyin. The rockets are named after the Long March of Chinese communist history.

History

Long March 3A launch

Long March 3B launch

China launched its first satellite, known as Dong Fang Hong 1 (lit. "The East is Red 1"), into Earth orbit on its Long March space rocket on April 24, 1970, becoming the fifth nation to achieve independent launch capability. Early launches had an inconsistent record, focusing on launching of Chinese satellites.

Starting in 1990, the Long March rocket entered the international market. However, several setbacks occurred during the early 1990s. On January 26, 1995, a Long March 2E rocket veered off course two seconds after take-off from Xichang space center and exploded, killing at least six on the ground. On February 14, 1996, a similar failure occurred during the launch of Intelsat 708: The rocket veered severely off course immediately after clearing the launch tower and crashed into a village.^[1]

Following the disaster, foreign media were sequestered in a bunker for five hours while, some have alleged, the Chinese military attempted to 'clean up' the damage. Officials later blamed the failure on an "unexpected gust of wind"^[2] Xinhua News Agency initially reported 6 deaths and 57 injuries.^[3]

In the aftermath of the explosion, U.S. satellite makers shared information that allowed the Chinese to determine that the problem was in the welds.^[4] This sharing of information was later deemed illegal by the United States, and U.S. satellite maker Loral Space and Communications was fined $14 million by the U.S. government.^[5]

For thirteen years starting in August 1996, 75 consecutive successful launches were conducted, including multiple milestones:

• On October 15, 2003, the Long March 2F rocket successfully launched the Shenzhou 5 spacecraft/orbiter carrying China's first astronaut into space; China thus became the third nation to send a person in space independently, after the Soviet Union/Russia and the United States.
• On October 12, 2005, Long March 2F launched the Shenzhou 6 with two astronauts.
• On June 1, 2007, Long March rockets completed their 100th launch overall.
• On October 24, 2007, the Long March 3A successfully launched (18:05 GMT+8) the "Chang'e 1" lunar orbiting spacecraft from the Xichang Satellite Launch Center.
• On September 25, 2008, a Long March 2F launched Shenzhou 7, China's first three-man mission and first EVA mission.

The string of successful launches ended on August 31, 2009, when the launch of Palapa-D partially failed due to a third stage malfunction.^[6]

On the June 11, 2013, a Long March 2F, launched from the Jiuquan Satellite Launch Center, putting three astronauts into orbit for the Shenzhou 10 mission.^[7]

As of March 2016, there have been 225 Long March missions.^[8]

Payloads

The Long March is China's primary expendable launch system family. The Shenzhou spacecraft and Chang'e lunar orbiters are also launched on the Long March rocket. The maximum payload for LEO is 12,000 kg (CZ-3B), the maximum payload for GTO is 5,500 kg (CZ-3B/E). The next generation rocket – Long March 5 variants will offer more payload in the future.

Propellants

Long March 1's 1st and 2nd stage uses nitric acid and UDMH propellants, and its upper stage uses a spin-stabilized solid rocket engine.

Long March 2, Long March 3, Long March 4, the main stages and associated liquid rocket boosters use dinitrogen tetroxide as the oxidizing agent and UDMH as the fuel. The upper stages (third stage) of Long March 3 rockets use YF-73 and YF-75 engines, using Liquid hydrogen (LH₂) as the fuel and Liquid oxygen (LOX) as the oxidizer.

The new generation of Long March rocket family, Long March 5, and its derivations Long March 6, Long March 7 will use LOX and kerosene as core stage and liquid booster propellant, with LOX and LH₂ in upper stages.

Variants

Timeline of Long March rocket families

The Long March rockets are organized into several series:

• Long March 1 rocket family
• Long March 2 rocket family
• Long March 3 rocket family
• Long March 4 rocket family
• Long March 5 rocket family
• Long March 6 rocket family
• Long March 7 rocket family

2A	2C	2D	2E	2F	3	3A	3B	3C	4A	4B	4C

Long March 8

A new series of launch vehicles in study, which is geared towards SSO launches.^[18]

Long March 9

Long March 9^[19] (LM-9, CZ-9, or Changzheng 9, Chinese: 长征九号) is a Chinese super-heavy carrier rocket that is currently in study. It is planned for a maximum payload capacity of at least 140,000 kg^[20] to LEO or at least 50,000 kg to Lunar Transfer Orbit.^[21] Its first flight is expected in 2025 in preparation for a lunar landing sometime in the 2030s. It has been stated that around 70% of the hardware and components needed for a test flight are currently undergoing testing, with the first engine test to occur by the end of 2018. The proposed design would be a three-staged rocket, with the initial core having a diameter of 10 meters and use a cluster of four engines. Multiple variants on the rocket have been proposed, CZ-9 being the largest with four liquid-fuel boosters with the aforementioned LEO payload capacity of 140,000 kg, CZ-9A having just two boosters and a LEO payload capacity of 100,000 kg, and finally CZ-9B having just the core stage and a LEO payload capacity of 50,000 kg.^[16] If produced, it would be classified as a super heavy-lift launch vehicle along with the American Saturn V and unsuccessful Soviet N1; and the Space Launch System and Falcon Heavy currently under development in the United States.

Long March 11

The Long March 11 is a solid-fuel rocket that applies China's largest solid-fuel rocket engine and was designed to meet the need to rapidly launch satellites in case of emergencies or disasters. Its first launch on 25 September 2015, was reported to be successful and launched 4 micro satellites into sun synchronous orbits.^[22][23]

Origins

The Long March 1 rocket is derived from earlier Chinese 2-stage IRBM DF-4, or Dong Feng 4 missile, and Long March 2, Long March 3, Long March 4 rocket families are derivatives of the Chinese 2-stage ICBMs DF-5, or Dong Feng 5 missile. However, like its counterparts in both the United States and in Russia, the differing needs of space rockets and strategic missiles have caused the development of space rockets and missiles to diverge. The main goal of a space rocket is to maximize payload, while for strategic missiles increased throw weight is much less important than the ability to launch quickly and to survive a first strike. This divergence has become clear in the next generation of Long March rockets, which use cryogenic propellants in sharp contrast to the next generation of strategic missiles, which are mobile and solid fuelled.

The next generation of Long March rocket, Long March 5 rocket family will be a brand new design, while Long March 6 and Long March 7 can be seen as derivations because they use the liquid rocket booster design of Long March 5 to build small-to-mid capacity launch vehicles.

Launch sites

There are four launch centers in China. They are:

• Jiuquan Satellite Launch Center
• Taiyuan Satellite Launch Center
• Wenchang Satellite Launch Center
• Xichang Satellite Launch Center

Most of the commercial satellite launches of Long March vehicles have been from Xichang Satellite Launch Center, located in Xichang, Sichuan province. Wenchang Satellite Launch Center in Hainan province is under expansion and will be the main launch center for future commercial satellite launches. Long March launches also take place from the more military oriented Jiuquan Satellite Launch Center in Gansu province from which the manned Shenzhou spacecraft also launches. Taiyuan Satellite Launch Center is located in Shanxi province and focuses on the launches of Sun-synchronous orbit satellites.

Commercial launch services

China markets launch services under the China Great Wall Industry Corporation.^[24] Its efforts to launch communications satellites were dealt a blow in the mid-1990s after the United States stopped issuing export licenses to companies to allow them to launch on Chinese launch vehicles out of fear that this would help China's military. In the face of this, Thales Alenia Space built the Chinasat-6B satellite with no components from the United States whatsoever. This allowed it to be launched on a Chinese launch vehicle without violating U.S. ITAR restrictions.^[25] The launch, on a Long March 3B rocket, was successfully conducted on July 5, 2007. A Chinese Long March 2D launched Venezuela's VRSS-1 (Venezuelan Remote Sensing Satellite 1) "Francisco de Miranda" on September 29, 2012.

See also

• China National Space Administration
• Shenzhou spacecraft
• Space program of China
• Tsien Hsue-shen
• Comparison of orbital launchers families
• Comparison of orbital launch systems
• Kaituozhe launcher
• Kuaizhou launcher

References

External links

Wikimedia Commons has media related to Long March (rocket family).

• Extensive information on the Chinese space program
• China Great Wall Industry Corporation
• NASA links - substitute year for other years
• Long March Engines List
• Rocket and Space Technology
• Chinese Launch Vehicle Overview