求描写火箭发射的英文报道

求描写火箭发射的英文报道
求描写火箭发射的英文报道

求描写火箭发射的英文报道
A Long March rocket (simplified Chinese:闀垮緛绯诲垪杩愯浇鐏?; traditional Chinese:闀垮緛绯诲垪杩愯浇鐏?; pinyin:Ch谩ngzh膿ng x矛li猫 y霉nz脿i hu菕ji脿n) 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.Confusingly,the rockets are abbreviated both LM- and CZ- in English.The rockets are named after the Long March of Chinese communist history.
Contents [hide]
1 Payloads
2 Propellants
3 Specifications of Long March rocket family
4 Origins
5 Launch sites
6 Commercial launch services
7 Launch history
8 See also
9 References
10 External links
[edit] Payloads
The PRC launched its first satellite,known as Dong Fang Hong 1 ("the East is Red"),to Earth orbit on its own Long March space rocket on April 24,1970,becoming the fifth nation to achieve independent launch capability.The Shenzhou spacecraft and Chang'e 1 lunar orbiter are also launched on the Long March rocket.The maximum payload for LEO is 9200 kg (CZ-2F),the maximum payload for GTO is 5200 kg (CZ-3B).The LM-5 variant will offer more payload in the future.
[edit] Propellants
As of 2003,the main stages and the booster rockets of Long March rockets use storable propellants with UDMH as fuel and dinitrogen tetroxide as the oxidizing agent.The upper stages (third stage) of Long March 3 rockets use YF-73 and YF-75 engines,in which use cryogenic fuel,Liquid hydrogen (LH2) as fuel and Liquid oxygen (LOX) as oxidizer.
[edit] Specifications of Long March rocket family
Model Status Stages Length
(m) Max.diameter
(m) Liftoff mass
(t) Liftoff thrust
(kN) Payload
(LEO,kg) Payload
(GTO,kg)
Long March 1 Retired 3 29.86 2.25 81.6 1020 300 -
Long March 1D Retired 3 28.22 2.25 81.1 1101 930 -
Long March 2 Retired 2 31.17 3.35 190 2786 1800 -
Long March 2C Active 2 35.15 3.35 192 2786 2400 -
Long March 2D Active 2 33.667
(without shield) 3.35 232 2962 3100 -
Long March 2E Retired 2 (plus 4
Strap-on boosters) 49.686 7.85 462 5923 9200 3500
Long March 2F Active 2 (plus 4
Strap-on boosters) 58.34 7.85 480 5923 8400 3370
Long March 3 Retired 3 43.8 3.35 202 2962 5000 1500
Long March 3A Active 3 52.3 3.35 241 2962 8500 2600
Long March 3B Active 3 (plus 4
Strap-on boosters) 54.84 7.85 425.5 5924 12000 5200
Long March 3C In development 3 (plus 2
Strap-on boosters) 54.84 7.85 345 4443 - 3800
Long March 4A Retired 3 41.9 3.35 249 2962 4000 (SSO)
1500
Long March 4B Active 3 44.1 3.35 254 2971 4200 (SSO)
2200
[edit] Origins
The Long March rocket is related to early versions of the Dongfeng missile (note that Dongfeng is the generic Chinese name for all of its land ICBMs).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.
[edit] Launch sites
There are four launch centers in China.They are:
Jiuquan Satellite Launch Center
Xichang Satellite Launch Center
Taiyuan Satellite Launch Center
Wenchang 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 the commercial satellite in future.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 comes.Taiyuan Satellite Launch Center located in Shanxi province and focuses on the lauches of Sun-synchronous orbit satellites.
[edit] Commercial launch services
China markets launch services under the Great Wall Industrial Corporation.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.[1] The launch,on a Long March 3B rocket,was successfully conducted on 5 July 2007.
[edit] Launch history
Main article:List of Long March rocket launches
Early commercial launches had a spotty record.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 15,1996,a similar failure during the launch of Intelsat 708 using a Long March 3B rocket resulted in an unknown number of casualties.[1] The rocket veered severely off course right after clearing the launch tower and landed in a rural village.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.The Chinese Xinhua News Agency eventually reported 57 deaths,but the extent of damage observed by foreign journalists whilst being whisked away from the disaster site suggested there may have been at least 200 and upwards of 500 killed.[2] In the aftermath of the explosion,U.S.satellite makers shared information which allowed the Chinese to determine that the problem was in the welds.However,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 in 2002,while admitting no wrong-doing.[3]
Since the improvements made after the 1996 accident,the reliability of the Long March rockets has been excellent,with zero failed launches.On October 15,2003,the Long March 2F rocket successfully launched the Shenzhou 5 spacecraft/orbiter carrying the China's first astronaut into space,and on October 12,2005,Shenzhou 6 with two astronauts; China became the third nation to send man into space on its own,after the Soviet Union/Russia and USA.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.