Photo: History of Qingmei Kan
Editor|Ome Kanshi
It's been almost two months since we flew into space, and the astronauts on board our Shenzhou-17 finally announced their first out-of-cabin operation on December 21!
The mission of the Shenzhou-17 astronauts was called "the first extremely challenging mission", and the astronauts successfully completed the mission 7.5 hours after leaving the capsule, and all the crew returned to the space station safely.
This can't help but make people wonder what kind of "extremely challenging" mission the astronauts of Shenzhou-17 carried out, and why did they start carrying out it only two months after they landed in space?
Shenzhou XVII aviation mission
In fact, the space environment is more dangerous than we imagined! Our space station has been hit by tiny meteorites many times in space, and the space station's solar wings have been damaged in many places.
And one of the missions of our Shenzhou-17 astronauts this time is to repair these damaged solar wings. This is part of the construction of the continental space station, but it is also the first time that it has carried out a repair mission, and there is no relevant mission experience, so it is called a "very challenging extravehicular maintenance mission", and it also has a certain degree of danger.
Some people may wonder what dangers can be in space, could it be aliens? In fact, space is also full of dangers, and the source of danger is a large number of tiny meteorites in low-earth orbit.
Recently, the International Space Station released a photo, in which the robotic arm of the space station was damaged by a few centimeters, and the culprit of this damage was only a miniature meteorite with a diameter of two millimeters!
There are 170 million miniature meteorites like this in our near-Earth space orbit, and the number of space debris with a diameter of more than 10 centimeters exceeds 10,000!
A small two-millimeter debris can penetrate the robotic arm of the space station, and according to calculations, a 10-centimeter-diameter space debris impact can already destroy a spacecraft.
Because there are so many "little pitfalls" in low Earth orbit, our space station is designed to protect against them.
Through the detection device, the location of the surrounding space debris is captured in advance, and then their flight path is calculated, and if there is space debris that may collide with the space station, it will adjust its flight attitude to avoid these space debris.
The probe has been used effectively on the space station, thus avoiding many possible collisions with space debris. There was even a time when it was predicted that it would meet Musk's Space X Starlink satellites in a narrow way, and we immediately avoided it.
But even if we are equipped with such an advanced probe, we still can't detect all the "miniature meteorites", and the space wing of the space station has collided with satellite space debris many times, resulting in damage.
The space wing is an important solar power generation facility of the space station, which is related to the normal operation of the entire space station. Considering the importance of the space wing, the Chinese air station decided to repair the space wing, and the astronauts of the Shenzhou-17 spacecraft carried out this difficult task.
So why has Shenzhou 17 been in space for almost two months, and now it has come out to carry out the mission?
Why is it only now that the task is out of the warehouse?
It can only be said that there are unforeseen circumstances in the sky, and this time the astronauts of Shenzhou 17 bumped into the "unforeseen storm": a solar storm!
This year, solar activity has entered an active period, with not only a surge in sunspot numbers, but also multiple flare eruptions and coronal mass ejections. This November alone saw multiple flares in the sun.
On November 5, solar activity triggered a geomagnetic storm on Earth, followed by a geomagnetic storm in late November and early December, affecting a scale that could even be observed in the suburbs of Beijing.
The aurora in Beijing taken by netizens
At present, we cannot summarize the periodic law of solar activity, but can only observe it in advance. Our astronauts' plans to go out of the capsule were disrupted by this unpredictable solar activity.
Such frequent solar activity throws a large amount of high-energy particle radiation into space, and our aviation suits are currently unable to withstand this concentration of radiation particles.
Therefore, during the peak period of solar activity in November, astronauts were unable to go out of the capsule, and could only hide in the core area of the space station, relying on the space station to avoid radiation damage.
Space Weather Warning Centre
Even if they hide inside the space station, the astronauts will not be completely safe. Because other effects from solar storms still threaten the space station.
Limited by current technology, the world's major space stations are built in low-earth orbit and are not completely detached from the influence of the atmosphere, and our space station is no exception.
In addition to releasing a large amount of radiation particles, solar storms also release a huge amount of heat. This heat is absorbed and expanded by the Earth's atmosphere, which increases the flight resistance of the space station and causes slowdown. If it does not return to normal speed in time, the space station is very likely to fall into the atmosphere and crash.
There have been examples of this before. In 2022, Musk's new batch of Space X Starlink satellites encountered changes in atmospheric resistance caused by solar storms, and all 40 of the 49 satellites crashed just five days after launch.
This shows the dangers of solar storms. Our astronauts also carry out the mission after it is determined that the solar radiation in space has been reduced to a safe level.
But the astronauts haven't done nothing for the past two months. Due to the frequent activity of the sun, after getting acquainted with the facilities of the air station, the astronauts also carried out various emergency training and survival drills.
Some people may wonder whether it is possible to survive in space? Actually, it is possible, because our space station and the Shenzhou spacecraft are two independent operating systems, and as long as the spacecraft and the space station do not have problems at the same time, the astronauts still have the possibility of survival.
If there is a safety problem with the space station, the astronauts can move to the spacecraft for safety, and if necessary, they can abandon the station and return directly to the surface.
If the Shenzhou spacecraft is destroyed by a meteorite, then the astronauts will have to take it to the space station and wait for the ground rescue, and the ground will also start the rescue plan and launch a backup spacecraft to rescue the astronauts within 8 and a half days.
However, fortunately, the astronauts of Shenzhou 17 did not encounter such an extreme situation, and after determining that the external environment was basically safe, the astronauts began to carry out the maintenance tasks that had been formulated long ago.
Smoothly exit the cabin and complete the mission
On December 21, astronauts Yang Hongbo and Tang Shengzhuo carried out the maintenance of the space wing, and astronaut Jiang Xinlin cooperated in the space station.
Under the guidance of ground researchers and the assistance of robotic arms, after seven and a half hours, the two astronauts successfully completed the first out-of-cabin repair mission and returned safely to the space station.
This is the first time that mainland astronauts have completed extravehicular maintenance work, and the successful completion of this repair mission has accumulated valuable experience, which will be more conducive to carrying out more complex extravehicular missions in the future. According to the announcement of the China Space Administration, the Sanming astronauts of Shenzhou-17 will also carry out extravehicular maintenance missions several times.
epilogue
Success doesn't happen overnight, it's slow.
Here, I wish the astronauts of Shenzhou 17 a smooth sailing and success in their next maintenance missions, and we look forward to your triumph!