Some countries are eager to put out the new technologies that were just developed yesterday and put them on display today; some countries are sneaking around in a low-key manner, and high and new technologies only appear at the most critical juncture, and even after foreign media reports, they are "unavoidable to announce", and the mainland belongs to the latter.
On January 26, 2022, a number of foreign media suddenly hyped up the "Chinese satellite threat theory", on the grounds that the mainland satellite carried a secret weapon similar to a mechanical arm, which could "kill the satellites of other countries in one blow", or forcibly "drag and pull" the target satellites, so that they deviated from the original orbit and were eventually scrapped.
The original initiator was an analysis released by ExoAnalytic Solutions, a space monitoring company in the United States. Brian Flaeherin, the company's chief architect, made a remark at a webinar hosted by the Center for Strategic and International Studies, a US think tank, on the 26th, claiming that a long-defunct Beidou-2 navigation satellite in China had "inexplicably" disappeared. After investigation by his company, the vanished Beidou satellite was towed away by China's SJ-21 satellite!
China's SJ-21 satellite first quietly approached the Beidou satellite, and then implemented a "close operation", the Beidou satellite under the traction of the SJ-21 satellite carried out a "space shift", from the original orbit to the "super graveyard drift orbit"! After reaching the preset position, the SJ-21 satellite separated from the Beidou satellite and quietly returned to low Earth orbit!
Graveyard orbit is relative to the Earth orbit, the general height of 36,000 km below the near circular orbit is considered to be geosynchronous orbit, below 2,000 km below the low Earth orbit, the vast majority of the world's spacecraft are located in these two orbital range, near geosynchronous orbit above 300 km beyond the space orbit is called graveyard orbit.
Cemetery track is, to put it bluntly, a place to store "garbage". With the increasing number of communication satellites, meteorological satellites, and space stations launched by various countries, especially Musk's launch of 42,000 satellites, the Earth's orbit has long been "dense", then it is necessary to clean up these scrapped spacecraft, and dragging them to the orbit of a larger cemetery in space is one of the ways to deal with it.
Therefore, foreign media called continental satellites with offensive purposes all "slander", on the contrary, the mainland has made a significant contribution to the world's space industry, and the country that really needs to do this work is the United States, because a considerable part of the space garbage in modern orbit is produced by him.
Moreover, the United States is the master of trouble. In 2021, the US surveillance satellite "271" tried to approach the mainland's "Shixing 20" satellite, which is one of the most advanced satellites on the mainland, weighing 8 tons several times that of other satellites, and the solar plate presented after the wings are extended is about 45 meters long, 10 meters longer than the wingspan of the Boeing 737! "Practice 20" also used a number of black technologies for the first time, and carried a large number of scientific research instruments, the importance of which is self-evident.
Another thing is that in 2021, two satellites of Musk in the United States were close to the continental space station, causing the space station to implement emergency collision avoidance twice. Therefore, it is a joke in the press to say that the Western media indiscriminately spew everywhere and turn a blind eye to the real scourge!
And then there's space junk
How much space junk is there in low-Earth orbit? A report released by the United Nations Agency for Outer Space found that there are currently more than 8,000 satellites in Earth orbit, while only more than 4,000 are in working condition, and nearly half of the satellites have become space junk.
According to studies, there are about 23,000 space debris larger than 10 centimeters, and 70 million fragments have not been traced, a total of about 30,000 pieces; about 900,000 pieces of debris between 1 centimeter and 10 centimeters; and hundreds of millions of millimeter-level space debris! 60% of this space debris comes from the disintegration of the spacecraft and 8% from rocket wreckage.
The power of space debris cannot be underestimated! The velocity of the debris in space is close to 7.9 km/s, the first cosmic speed, and the space debris at this speed is like a time bomb, disintegrating a satellite in minutes.
On May 4, 2013, Ecuador's satellite suddenly deorbited and eventually crashed, and the result was that the satellite collided with a super-sized "space junk" that was the wreckage of a Soviet rocket mailbox that had been wandering in space for years!
On March 18 and March 19, 2021, the mainland and the United States have a satellite that somehow suddenly "disintegrated", of which the US NOAA-17 satellite is a typical meteorological satellite and has been decommissioned for 8 years; the mainland's Yunhai-1 02 satellite has only been in service for more than a year. Some scholars have analyzed the high probability that they have been attacked by space debris.
The large International Space Station is a "key target" for space debris. In 2016, a 7 mm diameter crater appeared in the glass window of the space station's dome capsule, and by 2021, there was another 6 mm diameter hole in the Canadian robotic arm, and the attached insulation material had obvious breakdown marks. Both were caused by space debris.
How to dodge space junk
In the face of hundreds of millions of space junk, there are currently two main ways, one is to actively avoid collisions, and the other is to clean up.
There are two ways to actively avoid collisions, one is to detect incoming space debris in advance, stagger the debris through the lifting and descending of the spacecraft, and stagger the original intersection point by speeding up or down the spacecraft. The data shows that as of 2020, the International Space Station has implemented 28 active avoidance, of which 3 have been implemented in 2020. According to the European Space Agency, satellites under its jurisdiction perform an average of two active avoidances per year.
Another approach is to completely destroy the space debris, and dragging the space junk into graveyard orbit is a compromise solution. There are two types of ways to clear space debris, one is to use a robotic arm to capture a net, which belongs to contact destruction. For example, the satellite approaches the space debris, then extends the mechanical arm and pushes the debris, and the fragment falls into the atmosphere after being forced, and eventually turns into ashes in the hot atmosphere. The mainland has made a similar attempt with a communications satellite carrying a small robotic arm, and the effect is good.
There is also a non-contact type, such as the use of laser thrust, ion beam push, etc. In 1993, NASA proposed the "Orion" program, which mainly used ground-based pulsed lasers to remove space debris from low Earth orbit, and later used a laser transfer to orbit to clear, that is, equipped with lasers on spacecraft.
In fact, the mainland has accumulated rich technology and experience in cleaning up space debris and is at the forefront of the world. In 2016, the mainland launched the "Aolong-1" space debris active clearance vehicle, which has all its independent intellectual property rights, successfully carried out the detection, identification, tracking and removal of debris, accumulated experience for the subsequent large-scale removal of debris, and also provided a protective armor for other spacecraft!
Original: Blog post