The Shenzhou spacecraft the first Chinese manned spacecraft. It had carried one taikonaut into orbit for a 21 hour test flight. This was the fifth flight, with four previous unmanned tests of various lengths since
1999.
The word Shenzhou (神舟) has been variously translated as 'Vessel of the Gods', 'Divine Craft', 'Divine Mechanism' or 'Divine Vessel'. It is also a play on a literary name for China (神州).
At a cursory glance the Shenzhou seems very similar to the Russian Soyuz design. It is made up of three modules - the orbital module, reentry module and propulsion module. The total mass is 7800 kg, and the spacecraft is 8.55 metres long, with a maximum diameter of 2.8 metres. The four sets of solar panels generate a total of 1500 watts of power.
The orbital module is at the 'top' of the spacecraft. It is 2.8 metres long with a diameter of 2.25 metres. It contains everything that a taikonaut needs to live in space that isn't needed for the reentry. These are things like food, sleeping bags and the docking equipment. It also provides space for scientific or military equipment that can be different from flight to flight. Unlike the Soyuz it has its own set of solar panels, which are 12 square metres in area, and thrusters, so it can therefore perform an autonomous mission. For this reason it seperates from the rest of spacecraft before retrofire and can remain in orbit for up to six months. It is thought that the Chinese plan to use the orbital modules as a form of space station modules in the future.
In the middle is the reentry module, which has the dimensions of 2.059 metres long with the largest diameter at the base at 2.5 metres. This is the section where the taikonaut sits for launch and reentry and is the only piece that returns to Earth. It is 13% larger than the Soyuz, but has the same 'headlight' shape and has enough room for three taikonauts. It descends to the Earth under a single large parachute. The heat shield is jettisonned and retrorockets fire just before (a couple of metres above the ground) to further slow the descent.
The service module is at the rear. It contains all the equipment that is needed to keep the taikonaut alive - environment, power and propulsion. The dimensions are 2.94 metres long with the widest diameter of 2.8 metres. It has the main set of solar panels which are rotatable to maximise the electricity yield. They are twice the size of those on the orbital module at 24 square metres. The Chinese state that there are a total of 28 engines on this section of the spacecraft. These include the four main engines located at the rear of the spacecraft. These produce about 2000 N in total, with an expected burn time at retrofire of 30 seconds. The other engines are smaller thrusters that would be used to change the attitude of the spacecraft and for small translational changes ie for docking.
The first announcement of the spacecraft came in June 1999, when the first photographs appeared. This coincided with the announcement that the first mission would be in October of that year. The photographs showed the CZ-2F rocket, basically the CZ-2E rocket with slight changes to make it man-rated. The shroud around the spacecraft was found to be larger than the Soyuz.
Further news came in July 1999 when it was announed that the last of tracking ships the would be used during the missions had been completed. Around this time Chinese officials stated that the launch had would not be sometime in 1999. This is thought to have been due to a explosion that had occurred that included the manned hardware.
The first test flight launched November 19, 1999. This flight was 21 hours in duration or 14 orbits, the same as the manned Shenzhou 5. This was a basic test of the all the systems. It was launched into a 196.3 km by 324.4 km orbit and the spacecraft didn't manoeuvre during the flight and the solar panels were simple single cells not the unfolding panels that would be used on later missions. On the board the reentry module were 100 seeds. Also on board were a dummy astronaut, national flags, the flag of the Macao Special Administrative region, a banner with all the signatures of the scientists and engineers who participated in construction of the spacecraft and commemorative stamps.
On December 13, 2000, China and Nambia signed an agreement that would allow China to build a tracking station in the African country. The station would cover an area of 150 by 85 metres and consist of an administration building and two antennae.
The four tracking ships were set to sea on January 6, 2001, a signal that a launch was imminent. It was, as only three days later Shenzhou 2 was launched. The was the first time that a more complete spacecraft was launched. On board were many experiments and samples. These included a monkey, a dog and a rabbit in a test of the spaceship's life support systems. In all there were 64 experiments on board. These included 37 on a pallet mounted outside the spacecraft. They investigated such things as crystal growing, cosmic ray and particle detectors, and China's first gamma ray burst detectors. Intially it was in a 196.5 km by 333.8 km orbit and for the first time the Shenzhou performed a burn that changed its orbit, first to 327.7 km by 332.7 km then to 329.3 km by 339.4 km and finally to 328.7 km by 345.4 km. The orbital module was left in orbit for a six month mission. It raised its own orbit to 394 x 405 km high and was then allowed to decay. Shenzhou 2 landed January 16 in Inner Mongolia. There was no photographs released of the laned capsule unlike for Shenzhou 1. Western analysts speculate that this was maybe due a parachute failure causing the spacecraft to be be destroyed on impact.
In November 2001 the Nambia Tracking Station was completed. Six months later Shenzhou 3 launched on March 25, 2002. The spacecraft was said to be capable of supporting a human crew and dummy taikonauts which were said to replicate the actions of a human crew to test the life support systems. The reentry module stayed in orbit for a week. The orbital module stayed orbit for over 7 months performing several orbit changes. Images released on CCTV showed what appeared to be some sort of ELINT payload on the front of the orbital module of the Shenzhou. The drawings showed some sort of antennae system, which in animation shown in China included three telescopic booms that extended outwards in orbit.
The last unmanned test flight came December 29, 2002. Shenzhou 4 was the first of the spacecraft launched at night. The spacecraft was said to be perfectly capable of carrying a manned cargo. There was 52 scientific payloads on board in four main areas: observation of the Earth in microwaves, space environment monitoring, microgravity fluid physics and biological technology research. Once again the mission was a week in length and the Chinese released images of the spacecraft only 30 minutes after it had landed. The taikonauts training for the first mission were said to have trained in the spacecraft before launch.
It wasn't until 10 months later that the first manned mission was launched carrying the first taikonaut Yang Liwei. This is covered in detail in the Shenzhou 5 node.
Soon after the landing of Shenzhou 5, the Chinese space program managers said that the next manned launch would not be for one or two years. This could either suggest that there were slight but surmountable problems on the flight or that the Chinese are not trying to rush themselves as they are only in a race with themselves.
- http://www.astronautix.com/craft/shenzhou.htm
- http://www.spacedaily.com
- http://www.svengrahn.pp.se/histind/histind1.htm
Thanks to gn0sis for the Chinese Characters