China filed a complaint with the U.N. Committee on the Peaceful Uses of Outer Space, claiming that SpaceX’s Starlink satellites nearly collided with its space station, Tiangong, on two separate occasions. It says that Tiangong had to maneuver to avoid the satellites on July 1 and October 21.
Chinese Ministry of Foreign Affairs spokesman Zhao Lijian says the United States should “take immediate measures to prevent such incidents from happening again.”
China alleges that the two incidents are violations of the 1967 Outer Space Treaty, which states that space should be used for the benefit of all humankind, not individual countries. It also says that each nation can be held liable for damage caused by objects in space that cause damage to another nation’s assets, regardless of whether the objects are owned by the government or private companies like SpaceX.
SpaceX maintains a headquarters in Hawthorne, California, which would put it within U.S. jurisdiction. It plans to eventually launch as many as 42,000 Starlink satellites into orbit and has already launched almost 2,000 of them.
Some experts say that as many as three percent of these satellites are already non-functional – essentially corpses of satellites that could easily collide with another entity’s functional hardware without even the ability to maneuver away from it.
This has led to complaints about the risk of increasing the amount of debris in orbit, which already includes numerous defunct satellites and spent rocket stages. In the past, the International Space Station has had to maneuver to dodge rocket stages that date back to the Space Race in the 1960s.
Most recently, the International Space Station dodged debris from a previous Chinese anti-satellite weapon test. The 2007 test created 3,500 pieces of debris that could be tracked from the ground and drew criticism from the international space community.
Astronomers have also complained about interference with their observations. SpaceX responded by taking measures to reduce the reflectiveness of its Starlink satellites.
Further complicating the issue, SpaceX prefers to launch the satellites into a lower Earth orbit than Internet satellites launched by competitors like ViaSat. Many existing Internet satellites orbit in a geosynchronous orbit, which requires the satellite to orbit the equator at an altitude of 35,786 kilometers.
Most already-launched Starlink satellites orbit at altitudes of between 1,110 kilometers and 1,325 kilometers. In April, the FCC approved the launch of some Starlink satellites to altitudes of 540 to 570 kilometers. This drew challenges from competitors like ViaSat and Amazon’s Project Kuiper, who both alleged that the FCC did not properly consider the potential environmental impact of launching satellites into the lower orbit.
Elon Musk fired back that ViaSat simply doesn’t like the competition. The lower orbit allows for lower latency times, which can make Starlink attractive to people who regularly use Internet-based applications that require fast response times but don’t have many good alternatives for high-speed Internet access.
For all the complaints, SpaceX has made some effort to reduce the risk that Starlink satellites will collide with somebody else’s space-based assets. Starlink is capable of maneuvering to avoid a collision, which was apparently a variable in OneWeb’s previous allegation that a Starlink satellite nearly collided with one of its own that was being launched. (SpaceX denied the allegation.)
SpaceX says the propulsion systems can deorbit a non-functional Starlink satellite and they will naturally deorbit if the propulsion system doesn’t work.
SpaceX has also signed a memorandum of understanding with NASA to share information about the orbits of Starlink satellites to help avoid collisions.