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ShenZhou Spacecraft
ShenZhou (“Magic Vessel”) is China’s first spacecraft with manned capabilities. The development of the spacecraft began in the early 1990s under China’s manned space programme Project 921. Following four unmanned test flights between 1999 and 2002, the fifth spacecraft ShenZhou-5 successfully orbited China’s first astronaut on 15 October 2003. The next manned mission ShenZhou-6 is reportedly scheduled before 2006.
PROGRAMME
China’s current manned space programme, known as Project 921, was officially launched in September 1992. The initial target of the programme is to send a manned spacecraft into the earth orbit and recover it successfully. China’s step-by-step approach includes few unmanned test flights, followed by two or more manned missions.
The development of the ShenZhou spacecraft began in the early 1990s, with the spacecraft reported to be in engineering phase in 1996. Despite the highly classified status of the project, details of the ShenZhou spacecraft began to emerge in the late 1990s. It is understood that the ShenZhou spacecraft bears many similarities to the Russian Soyuz which, in turn, was similar to some early 1960s Apollo concepts.
To help save the project time and costs, the ShenZhou spacecraft has adopted certain Russian technologies. China has reportedly bought examples of the Soyuz-TM spacecraft technologies, including a complete re-entry capsule, an androgynous docking unit, a pressure suit as used by cosmonauts, and the life-support system. However, instead of copying these, Chinese engineers learned from them and applied what they have learned to the ShenZhou’s designs.
The first unmanned ShenZhou experimental prototype was successfully launched and recovered in November 1999, followed by the second experimental prototype flight ShenZhou-2 in January 2001. The first fully equipped spacecraft ShenZhou-3 was launched in March 2002, carrying a dummy astronaut for the test of the life-support system. The last unmanned mission ShenZhou-4 was carried out in December 2002.
The fifth launch, ShenZhou-5, was the first to carry a human (Lt. Col Yang Liwei) and occurred at 09:00 Beijing Time on 15 October 2003. This has made China the third country after the USSR/Russia and US in the world capable of sending human into space. The sixth launch, which is reported to be scheduled in 2005 or 2006, will carry two astronauts and stay on the earth orbit for three days.
DESIGN
The general layout of the ShenZhou spacecraft is similar to the Russian Soyuz. The spacecraft comprises three modules: a forward orbital module, a re-entry capsule, and an aft service module. Once the mission is completed, the service module and the re-entry capsule are separated from the orbital module by the ground command, and begins the retrofire. Then the service module is separated from the re-entry capsule and burns up in the atmosphere, while the re-entry capsule enters lower atmosphere and lands on the earth surface.
There are two pairs of solar panels mounted on the service and orbital modules, with a total area of 36 square metres, giving the spacecraft an average of 1.3kW electrical power, which is comparable to the base module of the Mir space station. The orbital module is equipped with its own solar panels, propulsions and flight control system for autonomous flight.
The ShenZhou spacecraft is capable of carrying up to three astronauts for a flight mission of up to a week, with the orbital module capable of flying autonomously for up to six months.
The spacecraft is powered by four main engines, with a total thrust of 2,000kg. Burn time at retrofire would be about thirty seconds.
ORBITAL MODULE
The orbital module contains space for experiments and other equipment operated by the mission crew. After the entry capsule and service module are separated for re-entry, the orbital module continues flying in the earth orbit for another six months before it finally burns up in the atmosphere.
During its autonomous flight, the orbital module can carry out various unattended scientific experiments. In the future missions, the remaining orbital module of a ShenZhou spacecraft could also be used for space docking with another spacecraft, forming a temporary space station. For such missions it would have a Russian-style androgynous docking system at the forward end of the orbital module.
Additionally, the orbital modules is said to be capable of carrying signal intelligence (SIGINT) payload, and/or reconnaissance CCD cameras (up to 1.6m ground resolution) for military purposes.
RE-ENTRY CAPSULE
The re-entry capsule is the only module protected by heat shielding to withstand the tremendous heat when entering the atmosphere. This design minimises the amount of material to be returned to earth, and therefore increases the space available to the spacecraft without increasing its weight.
The design of the ShenZhou re-entry capsule is said to be based on the Soyuz, with a larger size to accommodate up to three astronauts. The ShenZhou re-entry capsule uses the same landing technique as the Soyuz. After the capsule enters the atmosphere, the capsule deploys a single drogue, followed by a single main parachute. Just before the impact, the capsule ignite the landing rocket for soft-landing, another Soyuz trademark.
The capsule provides Soyuz-style moulded seats for up to three crew. The astronauts control the spacecraft via a fairly modern flight control panel. A Russian-style periscope provided a means of manually orienting the spacecraft for retrofire and a forward view during docking operations. Manual control of the spacecraft was via Soyuz-type hand controllers.
SERVICE MODULE
The aft service module developed by Shanghai Academy of Spaceflight Technology (SAST), contains life support and other equipment required for the functioning of the ShenZhou. It is larger than that of the Soyuz, with adjustable solar panels to obtain maximum solar insulation regardless of the spacecraft’s flight status.
LAUNCH ESCAPE SYSTEM
The emergency escape system of the ShenZhou consists of the escape tower, the payload fairing, and the orbital and descent modules. The escape tower would fire to pull the ShenZhou capsule and orbital module away from the booster in the event of a major booster malfunction from 15 minutes before launch to the point of escape tower jettison at T+120 seconds (39,000m altitude).
The payload firing, which also has its own power, could also be used to pull the spacecraft capsule and orbital module away from the booster from the payload fairing jettison (T+120 seconds) to T+200 seconds. The payload fairing is then separated from the spacecraft.
When the fault monitoring management system on CZ-2F launch vehicle senses an emergency situation, it automatically activates the launch escape system. Ground controllers could also activate the system by command if deemed necessary. On manned flights the astronauts could manually activate the system from within the capsule.
After T+200 seconds, an abort would consist simply of booster shutdown, separation of the descent module, and an emergency re-entry leading to a recovery either on Chinese territory or off the southern coast of Japan.
SPECIFICATIONS
Length: 8.65m
Diameter: 2.80m
Solar Panel Span: 19.40m
Total weight: 7,800kg
Date Last Updated: 8 November 2004
Shenzhou V:
