As we all know, space is an extremely harsh environment with high vacuum, microgravity, strong radiation, and very drastic temperature changes, and once people are exposed to space, they will face four major dangers of pressure loss, lack of oxygen, high and low temperature radiation damage. So, space is a deadly environment for the human body. When astronauts carry out spacewalks, they must leave the cockpit environment that protects themselves and enter such a harsh environment, although they have the protection of extravehicular spacesuits, they are also full of dangers and may be dangerous at any time.
When the Chinese space station carried out its first outing of the space station, it encountered such a thrilling moment. At that time, Liu Boming and Tang Hongbo were responsible for the first mission out of the cabin, and the actual task of Liu Boming and Tang Hongbo at that time was to verify the reliability of the equipment related to extravehicular activities and to lift the panoramic camera a.
Panoramic cameras are very important for the space station. Due to the large size of the space station and the construction of multiple structures, there will also be frequent structural installations, extravehicular activities, orbit maintenance, angle maintenance and other operations during the operation process, and it is of great significance to monitor these processes and real-time operational status. In addition, the space environment is complex, and even occasional micrometeorites hit the space station structure, which must be monitored in real time and immediately risk assessment.
The camera is located near the control torque gyroscope between the large and small column segments in the fourth quadrant of the core cabin. Among them, Liu Boming was transferred through the mechanical arm, while Tang Hongbo was independently crawling to the work point through the main path handrail.
Before the task, Liu Boming and Tang Hongbo also installed a foot limiter on the robot arm. Otherwise, there is no way for the robotic arm to "tie" and carry the astronaut for extravehicular operations.
When Liu Boming carried out extravehicular activities, the ground monitored that the space station encountered abnormal radiation, we all know that space is full of radiation, space environment radiation is mainly composed of galactic cosmic rays, solar high-energy particles, south Atlantic anomalous radiation belt particles.
Galactic cosmic rays are streams of high-energy charged particles from outside the solar system. The energy of the particle is 108 to 1 020 electron volts, and the flux density is 2 to 4 / (square centimeters · seconds). Heavy ions are the most harmful in galactic cosmic rays, which can not only penetrate the bulkhead of spacecraft, but also cause serious damage to tissues and organs after hitting the human body.
When a solar storm erupts, it releases a large number of high-energy charged particles, including proton, electron, and heavy nuclear particle streams, the vast majority of which are protons, which can penetrate the space capsule and spacesuit, causing physical damage to astronauts' body organs.
Due to the deviation of the geomagnetic field from the Earth's axis of rotation (about 11.5°), the magnetic field magnetic field line drops almost vertically in the South Atlantic 15°N~55°S, 15°E~90°W region, which is the South Atlantic magnetic anomaly. In the altitude range of 16 km to 320 km in the South Atlantic Anomaly, the proton flux with energies greater than 30 megaelectronvolts is even 4 orders of magnitude higher than at the same altitude in other regions, which can pose a threat to astronauts who operate extravehicularly in low-orbit flights in this region.
All in all, space radiation can destroy the body's D NA, causing the body to gradually weaken, brain damage, leukemia, and increase the incidence of cancer. The current earth orbit flight, due to the protection of the earth's magnetic field, atmosphere and spacecraft cockpit, the radiation dose received by astronauts in space does not exceed the prescribed limits. The cabin of the Tiangong space station has a multi-layer protective structure, which can shield most of the dangerous radiation.
However, during the spacewalk, the radiation measurement of the astronaut will be higher than that in the cabin, and if the solar particles erupt at this time, there may be radiation sickness, and even, the astronaut will be hit hard.
Taking the United States as an example, the American "Gemini Constellation" 9 astronaut Jean Although Senna was not exposed to abnormal radiation, the outer layer of the back of his spacesuit was scratched, exposed to sunlight, his back was sunburned, and the heat of the sun also damaged the clothing's life support system. When returning to the spacecraft cockpit after the extravehicular activity, he had to enter the cockpit with the help of his companion Stav.
In the report, the astronauts did not specifically tell where the abnormal radiation came from. After receiving the instructions of the ground personnel, Liu Boming urgently returned to the cabin to avoid, the extravehicular activities are very testing the astronaut's arm strength, it is difficult for people to control themselves in the weightless environment, and they go out with light movement, but if they want to stop, they have to spend a lot of effort. Liu Boming successfully returned to the cabin before the arrival of abnormal radiation, and after the radiation passed, Liu Boming went out of the cabin again for operations.
After that, Tang Hongbo conducted emergency return training, and Tang Hongbo had to climb to the farthest end of the "Tianhe" core capsule with his bare hands. After receiving the evacuation order, he turned back at the first time, returned to the hatch as quickly as possible, and directly entered the node module. Successfully completed the emergency return drill.
In fact, astronauts on the space station to carry out the mission, the sacrifice made far more than we imagined, in the case of Nie Haisheng, Liu Boming, Tang Hongbo as an example, astronauts will lose the sense of direction after returning to the earth, and the movement control, balance, functional flexibility and cognitive ability have been reduced. And during their spaceflight, the brain moves above the skull, and the volume of gray matter in the somatic cortex (which is responsible for processing sensory information) increases or decreases.
Therefore, after returning to the earth, it is also necessary to tailor the recovery plan according to the long flight time of the mission and the characteristics of the astronauts themselves, so that the 3 astronauts can complete the physical gravity and readaption, and the physiological indicators will recover to reach the expected goals.