At 1:16 Beijing time on November 8, 2021, after about 6.5 hours of outgoing activities, the Shenzhou 13 astronaut crew worked closely together to successfully complete all the scheduled tasks of the outgoing activities, and astronaut Zhai Zhigang and astronaut Wang Yaping safely returned to the heavens and the core module, and the outgoing activities were a complete success. Since then, Wang Yaping has become the first female astronaut in China to perform the outgoing mission, and has also taken the first step in China's female capsule outer space walk.
In order to successfully complete this important spacewalk mission, the three astronauts have been making a lot of technical preparations on the space station since October 16, during which time the three astronauts have transferred materials from the "Tianzhou-3" cargo spacecraft, tested new extravehicular spacesuits, conducted on-orbit medical examinations, conducted a number of space tests, and conducted drills such as emergency medical rescue and emergency evacuation in orbit. Especially in the orbit emergency evacuation and other exercises are very important, the space station is most worried about two types of accidents, one is the fire, one is the pressure leakage caused by the impact of foreign objects such as space junk on the space station, once these two accidents are uncontrollable, it is necessary to start the emergency evacuation procedure, and the three astronauts will enter the "Shenzhou XIII" spacecraft return capsule in time to return to the earth. The first priority of China's manned spaceflight project is to do everything possible to ensure the absolute safety of astronauts.
If it is said that the three crews of "Shenzhou XII" traveled for three months more to do the technical verification work of the space station, such as the control of the mechanical arm, the first use of the new generation of extravehicular spacesuits, and the residence of the core module of "Tianhe", then the "Shenzhou XIII" crew is a complete technical application practice, and it will do a good job in technical support for the large-scale space station construction to be launched next year. During the six-month mission, the Shenzhou XIII crew will carry out two or three outgoing activities, carry out manual remote operations, and carry out scientific experiments and tasks within the framework of space station construction. As for whether the number of departures is two or three times, the key depends on the completion of the first two jobs. As Chinese astronauts gradually fully adapt to the law of extravehicular activities, they will better carry out various types of extravehicular work, and the efficiency of the outgoing cabin will be greatly improved.
But there is no doubt that extravehicular activities are extremely dangerous space activities that not every country can do. Astronauts leave the protection of the spacecraft and enter the vast space alone, while facing the test of the harsh space environment such as vacuum, strong radiation, weightlessness and alternating sudden cold and heat, and unexpected major accidents will occur if they are not careful. In particular, space does not have a barrier to the Earth's atmosphere and magnetic field, and astronauts will be directly exposed to a variety of cosmic radiation, including solar rays ejected during solar flares, high-energy particles in the Milky Way, and non-ionizing radiation such as ultraviolet, infrared, and radiofrequency radiation. These radiations can cause varying degrees of harm to the human body, and if the safety limit is exceeded, it will cause astronauts to suffer from radiation sickness and even endanger their lives. At the same time, the space station orbits the earth for 90 minutes, half the time by the sun, half the time by the earth, the temperature exceeds 100 degrees Celsius when irradiated, and drops to minus 100 degrees Celsius during the barrier. In this extreme environment of alternating hot and cold, astronauts last for several hours to walk spacewalks, which is a great test of body and mind.
The key to The Chinese astronauts' ability to overcome these difficult challenges is due to the extravehicular spacesuits developed by the Chinese. The extravehicular spacesuit is 100 kg, two meters high, and consists of clothing, helmets, gloves and space boots, the most complex of which is the clothing, which has 6 layers from the inside to the outside. The innermost layer is the lining and urine collection device; followed by the liquid-cooled ventilation layer for heat dissipation; the third and fourth layers are the pressurized airtight layer that maintains the pressure inside the spacesuit and the restriction layer that restricts the outward expansion of the pressurized airtight layer; the fifth layer is the thermal insulation layer to cope with the extreme temperature difference changes outside the cabin; the outermost layer is the protective layer, made of a variety of fiber composite fabrics, with good softness, penetration resistance, wear resistance, high temperature resistance, combustion resistance, corrosion resistance, radiation resistance, and other mounting interfaces. Extravehicular spacesuit also has an independent backpack-type life support system, gas-liquid-electric support system, measurement and control and communication devices, it can be said that the extravehicular spacesuit itself is a miniature spacecraft, but the price is not cheap, more than 30 million yuan. In order to meet the needs of Chinese female astronauts, women's special spacesuits have also been successfully developed, which will make Wang Yaping's capsule smooth, safe and effective, which is also unique in the world.
It is worth mentioning that there is also an extravehicular mechanical arm, the extravehicular mechanical arm is powerful, in addition to arbitrarily grasping and releasing large loads, you can also "grab" the astronauts to send to the designated working surface and operation points, which greatly reduces the time for astronauts to "crawl" outside the cabin and greatly improves the efficiency of extravehicular operations. At the same time, the two robotic arms of the Chinese space station can also be combined and cascaded, becoming longer robotic arms to complete more space missions.
With the active promotion of space station construction projects, China's space station tonnage will also become larger and larger, more and more complex, more and more advanced, by the end of 2022, China will build a 100-ton space station, and normalize, manned long-term on-orbit operation. From the continuous technical verification and infrastructure construction of the Chinese space station to the technical application that has begun today, all of this is a major embodiment of China's aerospace science and technology progress. Although the spacewalk is only an important microcosm of manned spaceflight, the connotation of space science and technology reflected in it is enough to shock the international community, which fully shows that China has become a veritable space power.