The 3 astronauts of Shenzhou XIII have entered the countdown to "going home"!
According to the China Aerospace Science and Technology Corporation, the three astronauts of Shenzhou XIII have been working on the mainland space station for more than 5 months, according to the plan they will work and live in orbit for 180 days, and now they have entered the countdown to go home, and the 3 astronauts will begin to enter the preparation stage of returning next week, one step closer to the day of returning home.
The challenge of returning home
Many people should still have an impression of the return of the 3 astronauts of Shenzhou XII to the earth, when the ground staff found the Shenzhou XII return capsule, the staff made a series of inspections and preparations for it before opening the hatch, and when the hatch was opened, the 3 astronauts did not walk out of the return capsule by themselves, but were carried out.
This is actually because the continental space station is running in an orbit of about 400 kilometers above the earth, in a microgravity environment, and human bones and muscles have long been adapted to the environment on the surface of the earth, so in the microgravity environment, the amount of bone will be lost, muscles will atrophy, etc., although astronauts actively participate in sports activities on the space station, delay muscle atrophy, etc., but just return to the earth still need to adapt to the earth's gravity.
In addition, there is a period of high-speed falling time when returning, and then the parachute will be opened, and the opening of the parachute will also cause a certain impact on the astronauts.
In particular, Shenzhou 13 has been working and living on the mainland space station for about 6 months, and the longer the life, the greater the impact on the body, so the astronauts who have just returned to the ship are very vulnerable, and even the out of the capsule needs help from others.
Japanese astronaut Naoko Yamazaki went to the International Space Station in 2010 and carried out a 15-day mission, which supposedly had little impact on the human body in such a short time, but she said: "I remember that my head weighed like a stone, and even holding a piece of paper in my hand felt very heavy."
There are also some astronauts who even need to relearn to walk after a mission to the space station. For example, American astronaut Andrew J. Feustel went to the International Space Station on March 21, 2018 for a six-month mission, and after returning to Earth, he could not walk and needed to relearn how to walk.
Of course, this situation usually occurs when it has just returned home, and it will recover when it slowly adapts to the earth's gravity. However, the astronauts who have just returned from the flight are more fragile and need to be strictly protected.
Why quarantine after returning?
Astronauts who have just returned to Earth are very vulnerable, especially after 6 months on the continental space station, at which time the astronauts' immunity will decline.
However, on the earth, pathogens are very common, even some very common and not fatal pathogens, for astronauts who have just returned to the earth are very dangerous, such as: influenza virus, etc., in order to protect the safety of astronauts, astronauts must first isolate and recover after returning to the earth.
Isolation recovery stage takes about 3-4 weeks, in the first week of return, the isolation system refers to the three-level isolation system, the astronaut's residence should be ventilated and disinfected every day, all the staff in the apartment should also be isolated in the apartment, can not go out at will, other personnel who need to enter the apartment should be physical examination and disinfection before entering, wear masks, wear white coats, even if they enter, they are not allowed to shake hands with astronauts, hugs, etc.
From the second week to the third week, the prevention and isolation system of grade II infectious diseases is referred to, and then it is adjusted to the prevention and isolation system of grade I infectious diseases.
At this stage, the main thing is to let the astronauts re-adapt to the earth's environment, so to fully ensure the rest and dietary nutrition of the astronauts, in addition to the advice of the nutritionist, the astronauts can also tell the staff their favorite food, and the staff will prepare it.
During this period, the astronaut's cardiovascular system, motor system, balance and coordination function changes will be paid attention to, and then the focus will gradually be on cardiopulmonary reserve function, motor system function and structural changes, and the comprehensive recovery of physical and mental state.
Isolation recovery is only the first stage, followed by a medical recuperation period, this period is about 20-30 days, during this time the astronauts will gradually increase the amount of activity, the medical team will make a recovery plan according to the situation of each astronaut, but also according to the astronaut's physical condition to add nutrients, such as: calcium supplementation and so on.
The third stage is the recovery period, which takes about 3 months, during which the astronaut's physiological parameters need to be restored to the pre-flight state.
Only when the astronauts' physical fitness returns to the state they were in before the flight, the astronauts will enter the next round of training for the mission.
At present, there are a total of 16 astronauts with flight capabilities on the mainland, and the third batch of astronauts are in training, and it will be 2-3 years before they have the ability to carry out space missions.
On average, the continental space station welcomes two groups of Shenzhou crews every year, each with 3 astronauts, each performing about 6 months of missions, that is to say, 6 astronauts will perform space station missions every year.
Astronauts need to isolate and recover after completing the mission, so during the 16 astronauts' space station mission, each person's task is very heavy, and the training intensity is relatively large, and even Yang Liwei participates in the training throughout the process, the purpose is to ensure the complete success of the manned launch mission of the space station.
At present, the 3 astronauts of Shenzhou XIII are about to enter the countdown to go home, and next week they will prepare for the return to the earth, and after the 3 astronauts return to the earth, the mainland will launch the Tianzhou IV cargo spacecraft, and after the launch of Tianzhou 4, the 3 astronauts of the Shenzhou XIV spacecraft will also enter the continental space station.
During the period when the 3 astronauts of Shenzhou 14 are in orbit, the mainland will also launch two experimental modules to dock with the continental space station, and after docking, the space station can ensure that 3 astronauts live for a long time and meet the accommodation needs of 6 astronauts in a short period of time, so the Shenzhou 14 spacecraft and the Shenzhou 15 spacecraft will be in orbit.
Finally, I wish the three astronauts of Shenzhou XIII a smooth return to the earth and a complete success in the mission of the continental space station.