The basic function of extravehicular spacesuit is to protect astronauts from the harsh environment in space and provide microenvironment for astronauts' survival.
Shenzhou VII's extravehicular spacesuit will be designed with safety ropes. This can not only meet the needs of maintaining communication with the spacecraft and the ground, but also provide oxygen and food for astronauts' extravehicular activities and excrete waste.
In this regard, experts believe that the outer protective material of the extravehicular spacesuit is the key to its formation, and it should have the functions of radiation protection, ultraviolet protection, rapid cooling resistance and sudden high temperature resistance that the spacesuit in the cabin does not have.
Because the astronauts who leave the cabin may encounter a high temperature of more than 200 degrees on the side facing the sun and a low temperature of several degrees below zero on the side facing the sun. Special materials and protective layers must be used for this sudden change of quenching and sudden heating.
In order to cope with extreme temperature changes, most spacesuits will use many layers of fiber insulation, and then cover the outermost layer with a fabric that can reflect light.
Everyone generates heat during breathing, so astronauts will generate a lot of heat whenever they work.
If this heat is not excluded, the skin will produce a lot of sweat and cover the helmet, and the astronauts will be seriously dehydrated. To this end, researchers designed micro fans or water-cooled fabrics in spacesuits to eliminate excessive heat.
For example, inside the spacesuit, there is a "long underwear" made of nylon, elastic artificial fiber and special hose. Cold water from the spacecraft will flow through these hoses and take away the extra heat from the astronauts.
In addition, there is a fiber cover on the spacesuit, and there is a microphone and speaker in it, which can communicate hands-free. Astronauts can communicate with the ground control center and other astronauts through the transmitter and receiver in the spacesuit.
Every spacewalk will last for a long time, and the astronauts' bodies will continue to make urine. If astronauts need to use the bathroom in the spacecraft again, they will waste too much time in the process of getting in and out of the spacecraft.
Therefore, this is extremely unrealistic. To this end, astronauts will wear clothes that absorb urine and excrement. After the work is completed, the cloth will be discarded.
The water that astronauts need is put in plastic bags. The plastic bag can hold 19 liter of drinking water, which is connected by a small tube at the mouth of the astronaut and a drinking water pipe. The plastic bag has a long hole, where shell food bars can be put for astronauts who walk in space.
Everyone exhales carbon dioxide, and astronauts are no exception. If carbon dioxide in the sealed space of spacesuit is not removed, its concentration will rise to a dangerous level, which may lead to the death of astronauts.
The solution is that the air will first enter a box full of charcoal to remove the odor, then enter the carbon dioxide filtering part, then pass through a fan, and then return to the water cooling system after the water vapor is removed by the purifier.
The temperature is maintained at 128 degrees, and the conversion device on the spacesuit can provide oxygen supply and carbon dioxide removal for up to 7 hours.
Trunk shell is the main body of extravehicular spacesuit, and it is the assembly integration center of spacesuit. It is the most important thing to connect all kinds of equipment and instruments with it. The launch vehicle assembly plant of China Aerospace Science and Technology Corporation undertakes this development task.
The trunk shell of the extravehicular spacesuit is made of aluminum alloy thin-walled hardware. After assembly, it bears various loads of ground transportation and rising together with the backpack system, and has the functions of pressure protection, load support and sealing. It is a veritable "armor" of astronaut life.
On February 14, 2006, China Aerospace Science and Technology Corporation received the task at the beginning, which was at the peak of production before the first phase of China's space high-density launch, and the scientific research and production task of the launch vehicle assembly plant was very heavy.
Therefore, in the process of developing the first product, the launch vehicle assembly plant adopted the process technical preparation, process test and product design in parallel; Concurrent tooling design and product design; The "three parallel" working mode of mold design and mold manufacturing in parallel.
Generally speaking, product design, process design and manufacturing are organized in parallel and managed as a whole, which effectively solves the contradiction of tight time, heavy tasks and few personnel.
Because the development of extravehicular spacesuit is the first time in China, there is no experience to follow. The trunk shell is complex in shape, compact in structure and special in shape, which requires high product performance and accuracy.
Therefore, the launch vehicle assembly plant has successively overcome seven technical difficulties, such as thin shell forming of trunk, electron beam welding of hatch flange, pressure helmet forming, filter skeleton forming, air duct forming, welding deformation control and overall tooling coordination.
The thin trunk shell is a thin-walled piece, only15 mm. In addition to its unique shape, it also has five flange holes, some of which are even turned at a negative angle, which is extremely difficult to process and almost impossible to achieve by conventional technology.
The technicians of the launch vehicle assembly plant repeatedly conducted flanging tests with different thicknesses and materials. Finally, they solved the problem of thin shell forming and positioning by welding seam and positioning hole technology.
In addition to the trunk shell, the launch vehicle assembly plant has also completed the research and production of spacesuit extravehicular helmet, lower limb waist flange, ventilation and airflow distribution pipeline and other products, which has made outstanding contributions to the technical research and production of the whole spacesuit.
At the beginning of May of the same year, the launch vehicle assembly plant successfully completed the production task of the first extravehicular spacesuit sample. In July 2007, the factory completed the development of the first sample product and the change of appearance, initial sample and sample phase.