The Chinese space station urgently avoided collisions, why Is Musk's star chain so "arrogant" | quick comments

▲ Experts talk about the two times the US Star Chain satellites have approached the Chinese space station: the international community is coordinating the establishment of a mechanism to avoid spacecraft collisions. Photo / Beijing News our video screenshot

Recently, the official website of the United Nations Committee on the Peaceful Uses of Outer Space recently released news that on December 3, the Chinese Permanent Mission to the United Nations and other international organizations in Vienna sent a note verbale to the Secretary-General of the United Nations, informing them that the Starlink satellite launched by the US Space Exploration Technology Corporation (SpaceX) has approached the Chinese space station twice this year, posing a threat to the lives and health of astronauts on the Chinese space station.

Foreign Ministry spokesman Zhao Lijian also responded on December 28 that I can responsibly confirm to you that in July and October this year, the Starlink satellite launched by the US Space Exploration Technology Corporation approached the Chinese space station twice. During this period, Chinese astronauts are on missions inside the space station, and for safety reasons, the Chinese space station has taken emergency collision avoidance measures.

▲ "Tianhe" core module launch! Animation fully understands the Chinese space station. Video/Beijing News.

The Starlink satellite triggered an emergency collision avoidance incident, which is already a "habitual offender". On September 2, 2019, less than four months after SpaceX's first batch of 60 Starlinks was launched, the European Space Agency's (ESA) science satellite Aeolus evaded braking to avoid a collision with the Starlink-44 satellite. According to estimates at the time, the probability of a collision between the two was about one in a thousand, ten times the starting point of the European Space Agency's request to evade braking.

At the time, the European Space Agency tried to contact SpaceX, but SpaceX did not take any action. Afterwards, SpaceX claimed that a program failure of the company caused it not to receive emails from the European Space Agency.

In recent years, with the pace of human development of the universe, the safety problems caused by a large number of space satellites and space junk flying at high altitudes on the earth have become increasingly prominent. In 2009, a very famous satellite high-speed collision occurred, the American Iridium Company's commercial communications satellite Iridium 33 and the Russian military communications satellite Cosmos 2251 collided at a speed of 12 kilometers per second at a speed of 789 kilometers over the Temer Peninsula in Siberia, and a large amount of debris from the collision is still flying at a high speed of more than 700 kilometers in space.

Musk and SpaceX's Starlink program may pose more serious security risks. The goal of the Starlink program is to build a large constellation of satellites in low-Earth orbit. So far, SpaceX has launched a total of 1944 satellites, of which 1797 satellites are still in orbit. The future plans for the project are even more ambitious, with the Federal Communications Commission (FCC) already approving the launch of 12,000 Starlink satellites, and SpaceX is applying for a further 30,000 Starlink satellites on top of that.

According to statistics made by jonathan C. McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, 26 of the 1,797 starlink moons still in orbit have completely lost control, but they are still in low-Earth orbit, waiting for them to slowly descend under the action of the thin upper atmosphere and fall back to the surface.

The Starlink program has long provoked much discussion and criticism in the field of space exploration. In August, Hugh Lewis, a space debris expert and chief scientist in the astronautics research group at the University of Southampton in the United Kingdom, tweeted estimates of the close contact events caused by the Starlink program. He calculated the number of close-in encounter events using SOCRATES, a database of satellite orbital conjunction reports for assessing threatening space contact events. Since the beginning of 2019, a large number of close-up contact events between satellites (within 1 km) have been caused by starlink satellites.

After May 2021, more than half of the total number of close contact incidents caused by Starlink satellites has been achieved. In the face of widespread criticism and skepticism, SpaceX designed an automatic collision avoidance system for the Starlink program, but the Aeolus satellite in 2019 and the emergency collision avoidance incident on the Chinese space station this year show that this system is obviously not perfect.

In addition, another major problem caused by the Starlink program is light pollution. Numerous starlink satellites have seriously affected astronomical observations, triggering protests in the astronomical community. Musk claimed that he would modify the Satellite Chain satellites to reduce the reflectivity of the satellites to reduce light pollution. However, SpaceX's investment in this area is very limited, and the new modified satellites will still significantly interfere with astronomical observations.

These problems caused by starlink mean that how to coordinate the operation of many artificial satellites in the future, standardize space development, avoid causing security problems, and reduce the impact on other areas of human activity is a problem that government departments and space companies in the commercial space age must solve. No one wants scenes like the sci-fi movie Gravity to appear in reality. To this end, any space developer must bear corresponding international responsibility.

|, a special commentator of the Beijing News Telescopic (astrophysicist)

Edit | Chi Daohua

Proofreading | Li Lijun