Recently, the permanent mission of China to the United Nations and other international organizations in Vienna rarely informed the Secretary General of the United Nations by note that the satellite chain satellite launched by SpaceX approached the Chinese space station twice this year, forcing the Chinese space station to take preventive collision avoidance control ("emergency collision avoidance"). Not long ago, the United States was playing up the threat of Russian space debris to the international space station, but its own satellites really threatened the Chinese space station. What worries the old driver is that according to the information provided by China, when the US satellite approached danger twice, the member groups of Shenzhou 12 and 13 astronauts were on the space station, which means that the life safety of Chinese astronauts is also directly threatened. What does the star chain satellite want?! According to the Chinese side's report, xinglian-1095 satellite originally operated in an orbit with an average altitude of about 555 kilometers. During the period from May 16 to June 24, it continued to descend the orbit to an average orbital altitude of 382 km and maintained its operation at that orbital altitude. On July 1, a close proximity event occurred between the satellite and the Chinese space station. For safety reasons, the Chinese space station took the initiative to take "emergency collision avoidance" on the evening of July 1 to avoid the risk of collision between the two targets. The old driver noticed that xinglian-1095 satellite left orbit on September 20 and may have fallen into the atmosphere and burned. In other words, on July 1, it is likely to pose a threat to the Chinese space station in the process of preparing for decommissioning in the automatic orbit reduction mode. A similar situation has happened. In 2019, the "Aeolus" earth observation satellite of the European Space Agency urgently changed its orbit to avoid the satellite chain-44. At that time, the star chain satellite dropped to an altitude of 320 km and tested its technology of automatic disengagement from orbit. As a result, it was close to the "Fengshen" satellite operating at this altitude, resulting in collision risk. The star chain satellite claims to be equipped with an automatic collision avoidance system, which can track on orbit debris and spacecraft and avoid them automatically, but the system has failed many times. It is said that this function needs to be matched with the space tracking system on the ground, but since there has never been such a huge space satellite group before, the existing system is not enough to deal with this situation. If the dangerous accident close to China's space station can be reluctantly explained by "failure of automatic avoidance function of retired satellites", I'm afraid the second time is not so simple. According to China's briefing, the second "dangerous approach to the Chinese space station" occurred on October 21, and the satellite xinglian-2305 had a close approach to the Chinese space station. Given that the satellite is in continuous orbit maneuver, the maneuver strategy is unknown and the orbit error cannot be evaluated, there is a risk of collision with the space station. In order to ensure the safety of astronauts in orbit, the Chinese space station implemented "emergency collision avoidance" again on the same day to avoid the risk of collision between two targets. It is worth noting that at present, xinglian-2305 satellite has returned to the normal orbit altitude of about 555 km. Why did the satellite suddenly lower its orbit by about 100 kilometers? Some aerospace experts believe that the purpose of this move may be to enhance the communication performance of satellite constellations in local areas. In the planning of SpaceX, the company also plans to deploy a large number of satellites in an orbit of about 330 km. But there is another possibility. The United States will use this to detect China's space perception and test whether China can accurately grasp their actions. You know, the star chain program is no longer a simple Internet satellite constellation. It has established close ties with the U.S. military. In March 2019, the US Air Force awarded SpaceX a contract worth US $28 million, requiring it to carry out military service demonstration and verification of the "star chain" within three years. In November 2019, the US Air Force conducted an early low orbit technology verification test on the "star chain", including the test of direct interconnection between the satellite and the antenna array of the US Air Force fighter. Therefore, at the request of the Pentagon, it is not impossible for SpaceX to test China's space perception with the help of dangerous proximity to China's space station. Anyway, once something happens, it can also defend itself as a "private company" so as not to cause big international trouble. In addition, experts also reminded the old drivers that the "emergency collision avoidance" action of China's space station needs to consume additional fuel. If the American satellite chain satellites carry out similar actions frequently, it will significantly affect the on orbit life and maintenance cost of the space station. According to China's note, at present, China requests the Secretary General of the United Nations to inform all States parties to the outer space treaty of the relevant situation and draw the attention of all States parties to the fact that, in accordance with Article 6 of the outer space treaty, States parties are required to bear international responsibility for their activities in outer space (including the moon and other celestial bodies), whether government departments or non-governmental organizations, and shall be responsible for ensuring that the implementation of their activities complies with the provisions of this treaty. I hope the United States can really shoulder its due space responsibilities. (Xinhua News Agency)