US rejects charge that Starlink satellites endangered China’s space station

WASHINGTON: The United States, in an official “note verbale” to the United Nations, has refuted China’s unusual diplomatic accusation that SpaceX’s Starlink satellites have endangered, and continue to endanger, its crewed space station.

“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,” asserts the Jan. 28 missive filed with the UN Office of Outer Space Affairs in Vienna.

Beijing, in its own Dec. 3 note verbale to the same UN office, complained that on two occasions — once in July 2020 and once in October 2021 — the station’s newest core module, Tianhe, had to dodge a Starlink to avoid a crash. The complaint also asked the UN to “remind States parties” (i.e. the United States) about their obligations under the 1967 Outer Space Treaty to ensure that their space operators follow the treaty’s provisions. The move was politically odd, both in the fact that it seemingly came out of the blue and that the Office of Outer Space Affairs has no official role in mediating such disputes.

The US counter-missive stresses that US Space Command, via the 18th Space Control Squadron, routinely warns all nations, including China, of dangerously close approaches between space objects (both active satellites and debris). Since 2014, the note adds, the US specifically has been providing warning information to Beijing especially of emergency situations.

Further, the US asserts, Beijing didn’t use available communications channels to voice its concerns and seek to resolve them — and that, in essence, Chinese authorities have failed to avail themselves of the tools that would ensure they have advance warning of any dangerous on-orbit situations.

“The United States is unaware of any contact or attempted contact by China with the United States 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 prior to the note verbale from China to the Secretary General.”

SpaceX did not respond to a request for comment.

Noting that Washington believes bilateral information sharing is the best way to handle space collision risks, the US response “urges all nations, in particular those with human spaceflight missions, to provide updated contact information on designated entities authorized to engage in timely exchanges of appropriate information on on-orbit human spacecraft operations, in particular those entities that are responsible for adopting precautionary and response measures for crewed missions.”

Gaps In International Space Governance

Several analysts who keep close tabs on UN space diplomacy said the US-China tit-for-tat highlights the continued lack of international levers for dealing with rapidly increasing on-orbit congestion and the resulting rising risks to space operations.

“Clearly an exchange of diplomatic notes is better than an exchange of Twitter fire (or worse). But diplomatic notes won’t fill in the gaps in space governance and traffic safety,” Jessica West of Canada’s Project Ploughshares said.

“We have a huge infrastructure deficit when it comes to space governance, which stretches across the spectrum of uses and users,” she added. “We need better access to timely and trusted data, better points of communication and better ways to work with another to develop additional means and mechanisms of collective safety.”

Secure World Foundation’s Victoria Samson agreed that the situation “underlines the importance of information-sharing in a timely manner, particularly when it comes to concerns about the safety of human spaceflight.”

How Close Is Too Close?

Another problem, Samson said in an email, is that different nations — indeed, even different satellite operators from the same country — use different models to calculate collision risks, and have different thresholds for what is considered dangerous.

For example, there is no US national “threshold” for when an operator should maneuver its spacecraft (if it can) to avoid a collision; nor any rules for whose responsibility it is to move when the potential collision involves two active satellites. And while there are UN best practice guidelines set by the Committee on the Peaceful Users of Outer Space (COPUOS), they do not proscribe specifics on collision avoidance.

Thus, the heart of the US-China squabble may simple be a difference of opinion on how close is too close. (Sadly, neither the US or Chinese authorities or SpaceX have released the exact distance that the Starlinks passed by the Chinese Space Station.)

“Different operators have different concepts of risks,” Samson said. “It would be helpful to have at least a baseline level of risk (maybe related to human spaceflight) where if it is reached, information is shared.”

And even though the number of countries with their own radar and telescopes to “see” where space objects are moving is growing, those space situational awareness (SSA) capabilities are not coordinated and often come up with different results, she added.

“I also think it demonstrates that as we see the proliferation of SSA capabilities globally, we are going to run into more circumstances where the different networks have different takes on space objects’ placement and trajectories; we will need a process to iterate these differences, again in a timely manner, in the name of spaceflight safety,” Samson said.

The COPUOS Scientific and Technical subcommittee starts Feb. 7 in Vienna, and both space debris mitigation and enhancing current best practices are on the agenda, notes Chris Johnson, Secure World’s advisor on space law.

“It would be wise and ambitious if the Committee were to discuss openly and constructively about data sharing, lines of communication between human spaceflight programs, potential conjunctions and the risk threshold of how close is worrying, and basically how to not play ‘chicken’ in space,” he said in an email.