Shenzhou spacecraft
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Shenzhou (Template:Zh-cp) is the name of a spacecraft from the People's Republic of China which first carried a Chinese astronaut into orbit in 2003. Development began in 1992, with the first four unmanned test flights in 1999, 2001 and 2002. It is launched on the Long March 2F from the Jiuquan Satellite Launch Center.
The name is variously translated as "Divine Craft", "Divine Mechanism" but also a pun on a literary name for China with the same pronunciation (神州; literally "Divine Land").
Shenzhou_spacecraft_diagram.png
Shenzhou spacecraft diagram
The basic shape and division into modules resembles that of the Russian Soyuz spacecraft, and there has been tight cooperation with Russian space agencies and companies beginning in 1994, which also provided blueprints and transfers of full-scale Soyuz spaceships to China. Russian help was also important in the area of astronaut training.
Notwithstanding, both official Chinese sources as well as many Western analysts note that the Shenzhou is not merely a copy of the Soyuz and contains substantial amounts of indigenous design. In particular, the Shenzhou is substantially larger than the Soyuz and also contains a powered orbital module which is capable of autonomous flight, unlike the Soyuz equivalent.
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Design
Like the Soyuz, the Shenzhou consists of three modules: a forward orbital module (轨道舱), a reentry capsule (返回舱) in the middle, and an aft service module (推进舱). This division is based on the principle of minimizing the amount of material to be returned to Earth. Anything placed in the orbital or service modules does not require heat shielding, and this greatly increases the space available to the spacecraft without increasing weight as much as it would if those modules were also able to withstand reentry. Thus both Soyuz and Shenzhou have more living area with less weight than the Apollo spacecraft.
The orbital module contains space for experiments, crew-serviced or operated equipment, and in-orbit habitation. The reentry capsule contains seating for the crew, and is the only portion of the Shenzhou which returns to Earth's surface. The shape of the reentry capsule is a compromise between maximizing living space while allowing for some aerodynamic control upon reentry.
The aft service module contains life support and other equipment required for the functioning of the Shenzhou. Two pairs of solar panels, one pair on the service module and the other pair on the orbital module, have a total area of over 40 square metres, indicating average electrical power over 1.5 kW (three times that of Soyuz and greater than that of the original Mir base module).
The orbital module is equipped with its own propulsion, solar power, and control systems, allowing autonomous flight. In the future the orbital modules could also be left behind on the planned Chinese project 921/2 space station as additional station modules. In the unmanned test flights launched so far, the orbital module of each Shenzhou was left functioning in orbit for several days after the reentry capsule's return, and the Shenzhou V orbital module continued to operate for six months after launch. Significantly the docking adapter in the orbital module is based on the adapter used in the Apollo-Soyuz Test Project and is compatible with both Soviet and American docking adapters. It is therefore technically possible for the Shenzhou spacecraft to dock with the International Space Station although as of 2005 no such dockings have been planned.
History
China's first efforts at human spaceflight started in 1968 with a projected launch date of 1973. Although China did launch an unmanned satellite in 1970 and has maintained an active unmanned program since, this attempt was cancelled due to lack of funds and political interest.
The current Chinese human spaceflight programme was authorized on April 1 1992 as Project 921/1, with work beginning on January 1 1993. The chief designers include Qi Faren and Wang Yongzhi. The first unmanned flight of the spacecraft occurred on November 20 1999 after which Project 921/1 was rechristened Shenzhou, a name reportedly chosen by Jiang Zemin. A series of three additional unmanned flights ensued. The Shenzhou reentry capsules used to date are 13% larger than Soyuz reentry capsules, and it is expected that later craft will be designed to carry a crew of four instead of Soyuz' three.
The fifth launch, Shenzhou 5, was the first to carry a human (Yang Liwei) and occurred at 9:00 (UTC +8) on October 15, 2003.
Like similar space programs in other nations, Shenzhou has been somewhat controversial with some in China questioning whether China should spend money on launching people into space, arguing that these resources would be better directed elsewhere. Indeed, two earlier human spaceflight programs, one in the mid-1970s and the other in the 1980s were cancelled because of expense.
In response, a number of justifications have been offered in the Chinese media. One is that the long term destiny of humanity lies in the exploitation of space, and that China should not be left behind. Another is that such a program will catalyze the development of science and technology in China. Finally, it has been argued that the prestige resulting from this capability will increase China's stature in the world.
The Chinese media has heavily promoted the experiments undertaken by Shenzhou, particularly exposing seeds, including some from Taiwan, to zero gravity and radiation. Most scientists, however, discount the usefulness of this type of experiment, and many have suggested that like the focus of NASA on spinoffs, this is mainly to gain public support for spaceflight from a nation that is still predominantly agricultural.
Some Western news media outlets have suggested that there are important military implications for China's ability to put astronauts into space. However, the Chinese media has downplayed possible military motivations although Shenzhou's orbital module, staying in orbit for a few months before falling back to earth and disintegrating, is equipped with a high-resolution observation camera, which could be used for military intelligence.
However the experience of both the United States and the Soviet Union in the 1960s suggests that the military usefulness of human spaceflight is quite limited and that practically all military uses of space are much more effectively performed by unmanned satellites. Thus while the Shenzhou orbital module could be used for military reconnaissance, there is no military reason for incorporating such as system in a manned mission, as China could and does use purely unmanned satellites for these purposes.
Missions launched
- Shenzhou 1 - November 19 1999 - unmanned test flight
- Shenzhou 2 - January 9 2001 - carrying live test animals
- Shenzhou 3 - March 25 2002 - carrying a test dummy
- Shenzhou 4 - December 29 2002
- Shenzhou 5 - October 15, 2003 - 14 Earth orbits carrying Yang Liwei
Planned missions
- Shenzhou 6 - scheduled for second half of 2005, 5-day mission with two astronauts.
- Shenzhou 7 - likely to launch 2006 with two man crew. Perform spacewalk.
- Shenzhou 8 - docking with orbital module of Shenzhou 7. Three person crew likely to include first Chinese woman in space.
Future missions may include:
- Late 2007 Launch mini space lab.
- 2008 Shenzhou 9 docking to lab with a short human tending mission.
- 2008 Shenzhou 10 Olympics spectacular long stay man tended mission.
See also
External links
- http://www.astronautix.com/craft/shenzhou.htm
- "China's first astronaut revealed", BBC News Online, March 7, 2003; [1] (http://news.bbc.co.uk/1/hi/sci/tech/2829349.stm)de:Shenzhou
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