CZ-4CLong March Space Launch Vehicle
CZ-4B/2 = CZ-4C
The Chinese CZ-4C was actually flown for the first time as the CZ-4B/2 on November 6, 2004 and was later flown as the CZ-4C on November 11, 2007 and later on May 27, 2008 . Both were launched from the Taiyuan (TSLC) Satellite Launch Center . The booster is upgraded design of the CZ-4B booster with a second stage engines modified to be capable of being restarted in space. In addition to using the enlarged CZ-4B payload shroud beefed up structural rings were added at the base of the first stage and second stage. Environmental inter-stage covers were also added that are jettisoned at launch. To date it has been used to launch two SAR-RECSAT’s satellites and one polar orbiting meteorology imaging satellite.
The LM-4C was developed and manufactured by the Shanghai Academy of Spaceflight Technology. Based on its three stage design and second stage restart precision orbital capability it can be expected to continue to launch these heavier more demanding satellites. It appears to be the basic CZ-4B booster with the improved optional operational restart second stage engine modification as well as an existing third stage already proven repeatedly. For Further information on the CZ-4B see: http://www.globalsecurity.org/space/world/china/cz-4.htm This modified performance capability has given it a 4,200 kilogram low earth orbit insertion capability as well as a 900 kilometer sun-synchronous orbit 2,800 kilogram payload capacity. It also has a 1,500 kilograms capability to GTO. It primary mission like the CZ-4A and CZ-4B is for sun-synchronous orbital insertion missions. The CZ-4A third stage is a specially designed unit powered by the YF-40 main engine. The payload capacity of the CZ-4A into a sun-synchronous orbit is cited as 2.5 metric tons (References 159, 189-190) while the CZ-4C has a 2.8 metric ton capability.
The CZ-4's third stage, however, is newly developed, featuring a thin wall common inter-tank bulkhead tankage and two-engine cluster with both engines gimbal mounted for movement about two perpendicular axes. The 3rd stage engine cluster connects to the tank aft bulkhead through the engine bay. The booster appears to have been derived for its first two stages from the CZ-3A booster. It has a launch thrust of 2,960,000 kN utilizing highly toxic hypergolic UDMH and nitrogen tetroxide storable propellants in all three stages with a total launch mass of 250,000 kilograms. It is basically 3.35 meters in diameter with a height of about 45.80 meters
On 12 November 2007 China’s new Long March 4C rocket launched the 2.7-tonne advanced Yaogan-III remote-sensing satellite from Taiyuan into a 600-km Sunsynchronous orbit. The Long March 4C has an upgraded second stage that can be restarted in space. Both the launcher and the spacecraft were built by the Shanghai Academy of Space Flight Technology, a division of the China Aerospace and Technology Corporation. Yaogan-III is surveying land resources, aiding the estimation of crop yields, and assisting disaster prevention and relief efforts.
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