China’s first unmanned docking in space is on course for Nov. 3 following the Nov.1 launch of the Shenzhou 8 spacecraft on a Long March 2F/G booster at the Jiuquan Space Center in the Gobi desert.
A successful docking will be a significant step toward Chinese autonomous docking capability to establish a 60 ton space station by 2020.
The flight marks the 149th launch of the Chang Zheng (CZ) launch vehicle family, the 50th successful orbital mission launched from Jiuquan, and the 12th successful orbital launch from China this year.
To prepare for the docking the Tiangong 1 space module launched on Sept. 29 has been maneuvered to about 10 mi. lower into a 343 km. (213 mi.) docking orbit. It was also commanded to yaw 180 deg. to face its docking mechanism toward the approaching Shenzhou.
According to the Chinese the docking maneuvers will start when the two vehicles are 20 km apart. In the second stage of the process there will be three parking points at 5 km., 400 m. and 140 m. Their relative positions must remain accurate for mission controllers to determine their status and decide whether to continue or abort the docking.
Contrary to reports at a recent space fair in South Africa, Shenzhou-8 will act as the “active vehicle”, while Tiangong 1 will act “passive vehicle”.
Sensors on both spacecraft will start transmitting information about the velocity and distance. With the distance getting closer the data sent to the ground control will be more accurate, so that ground-based monitoring and control personnel can carefully monitor the operations.
Chinese Mission Control has never had to take dynamic action, or emergency measures that eventually will be needed in manned and unmanned dockings as the U. S. and Russia have learned. The Chinese have a rigid command structure and it remains to be seen how smoothly they can react to abnormal situations, should they occur.
To finish the docking the relative velocity of the two vehicles will slowdown to 0.2 meters per second relative speed and the lateral deviation of no more than 18 cm.
The two spacecrafts will remain docked for 12 days and after that they will separate to try a new docking at an undetermined date. After another (shorter) period of docked operations, Shenzhou-8 will return to earth within a day carrying a major joint German/Chinese science payload called SIMBOX.
According to the DLR (German Aerospace Research Agency) the SIMBOX (Science in Microgravity Box) experimental facility contains 17 experiments from the fields of biology and medicine, which will be conducted by German researchers together with their Chinese colleagues.
This is the first time that the China Manned Space Engineering Office (CMSEO) has cooperated with another nation in the use of Shenzhou – the core of China’s human spaceflight program. The DLR was tasked with the program and project management for the German part of the mission share by the Federal Ministry of Economics and Technology.
Astrium in Friedrichshafen built the SIMBOX facility and seven German universities have contributed experiments to the SIMBOX project.
Within SIMBOX, plants, nematodes, bacteria and human cancer cells will be exposed to zero gravity and space radiation for nearly three weeks. These experiments will include investigating the crystallization of medically relevant biomacromolecules. The objective is to tackle fundamental biological and medical questions. Where exactly does gravity intervene in biological processes? How can the immune system be strengthened?
In addition to the six German experiments, the Universities of Erlangen and Wuhan are carrying out a joint experiment, in which, using a miniature ecosystem with algae and fish, researchers are studying the material and energy flows in a closed system. The aim is to develop a biological life-support system to produce oxygen and food as well as treat water in future long-duration space missions.
In a second German-Chinese experiment, scientists at the University of Hamburg and the Institute of Biophysics in Beijing will investigate the crystallization of medically relevant proteins in space. Both proteins and enzymes play a major role in the development of new active pharmaceutical ingredients, targeting the multidrug-resistant bacteria MRSA (Methicillin-Resistant Staphylococcus Aureus) and the vector-borne parasites that cause malaria.
The SIMBOX facility accommodates a total of 40 experimental units, each approximately the size of a smart phone. The test facility weighs 25 kilograms and has a volume of 34 liters.
Some experimental units are simple devices such as miniature aquariums or plant chambers, but there are also complex types equipped with several chambers, pumps, lighting and sensors, as well as measuring systems. In orbit, some of the experimental units are exposed to zero gravity, whereas others are placed in a centrifuge producing Earth-like gravity. A comparison of pairs of samples will provide information on the effects of microgravity on the biological specimens.