On Dec. 3, 2021, the Permanent Mission of China to the United Nations (UN) submitted a note verbale to the UN’s Committee on the Peaceful Uses of Outer Space. It alleges that “Starlink satellites launched by Space Exploration Technologies Corporation (SpaceX) of the United States of America have had two close encounters with the China Space Station,” separately on July 1 and Oct. 21, 2021. So, it endangered the safety of the Chinese. Therefore, China Space Station had to implement preventive collision avoidance control.
In a Jan. 28 note verbale, Washington told the UN that since November 2014, the U.S. has provided spaceflight safety information to the Chinese regime, “including emergency notifications of high-risk collision hazards between crewed and robotic Chinese spacecraft and other space objects.”
The U.S. side also added, “Because the activities did not meet the threshold of established emergency collision criteria, emergency notifications were not warranted in either case.”
The U.S. note said they had calculated the two specific examples in the Chinese note verbale to the Secretary-General before the incident and concluded that the collision probability was insignificant.
The U.S. also said that “If there had been a significant probability of collision involving the China Space Station, the United States would have provided a close approach notification directly to the designated Chinese point of contact.”
The note verbale also stated that the U.S. was unaware of any contact or attempted contact by China with the U.S. Space Command, the operators of Starlink-1095 and Starlink-2305, or any other United States entity to share information or concerns about the stated incidents before the note verbale from China to the Secretary-General.
On Feb. 10, at a regular press conference of the Chinese Foreign Ministry, spokesman Zhao Lijian said that the U.S. side has no right to establish a threshold of emergency collision criteria unilaterally. Zhao added that after the incidents, the Chinese authorities tried to get the U.S. side by email several times but received no reply.
An astrophysicist at the Harvard-Smithsonian Center for Astrophysics, Jonathan McDowell, said no internationally accepted standard exists for an “emergency collision” in outer space.
McDowell, who has long tracked the trajectory of SpaceX’s Starlink satellites, explained that because Starlink satellites are constantly changing their orbits, this is the reason why the U.S. standard for the close-proximity standard is in question.
In addition, he said that each party involved should take responsibility for the Earth’s orbit becoming crowded. Without more collaboration among all parties, it would be difficult for these systems to be effective. He also cited that the International Space Station had to avoid debris from China’s 2007 anti-satellite test on several occasions.
A description on the Starlink website says the satellite has autonomous collision avoidance technology embedded in it that allows it to automatically dodge when it detects a possible collision with oncoming space junk, the space station, or any other space object.