Two satellites from the fast-growing constellations OneWeb and SpaceX Starlink dodged dangerous convergence with each other in orbit over the weekend, according to representatives of the US Space Force and OneWeb. This is the first known collision avoidance event between two rival companies seeking to create new space broadband networks.

Starlink satellites in the night sky (Patrick Pleul | picture alliance | Getty Images)
On March 30, five days after OneWeb launched its next batch of 36 satellites with the help of the Russian Soyuz-2.1b rocket, the company received several “red warnings” from the 18th space control squadron of the US space forces about a possible collision with satellite Starlink. Since the operating altitude of the OneWeb constellation is much higher (about 1200 km from the Earth’s surface), during the launch, the vehicles must pass through the SpaceX Starlink satellite network, which rotate at an altitude of about 550 km.
One warning from the US Space Force pointed to a 1.3% chance of collision, with two satellites approaching 60 meters – dangerously close by the standards of satellites in orbit. If a collision occurs, it could cause disaster: hundreds of debris could damage the following satellites.

A batch of 60 250-kg Starlink Internet satellites (SpaceX)
Currently, there is no national or global body that would compel satellite operators to take action in the event of predicted collisions. Following urgent warnings from the U.S. Space Force, the OneWeb and SpaceX Starlink teams had to coordinate satellite maneuvers via email.
In coordination with OneWeb, SpaceX turned off its AI-powered automated collision avoidance system and allowed OneWeb to remove its satellite from the route, OneWeb spokesman Chris McLaughlin said. It was unclear exactly why SpaceX decided to shut down the system – the company is not commenting on this story.

36 ready-to-launch OneWeb satellites (left) and 60 – SpaceX Starlink (OneWeb | SpaceX)
SpaceX’s automated collision avoidance system has previously raised concerns with other satellite operators, who say they have no way of knowing which way the system will move the Starlink satellite in the event of a close encounter. “The problem is in the coordination of actions– says Mr. McLaughlin. – It is not enough to say, “I have an automated system,” because the other party may not have such a system and will not understand what yours is trying to do. “…
SpaceX has roughly 1,370 Starlink satellites in orbit and is preparing to launch thousands more, possibly tens of thousands in the future. So far, OneWeb has launched 146 satellites out of approximately 650 that it has planned for a similar global network operating in higher orbits. Jeff Bezos’ Amazon has pledged to join the race and plans to launch more than 3,000 satellites into low Earth orbit. China is also hatching such plans.

One of the satellites of the SpaceX Starlink constellation in orbit around the Earth (SpaceX)
“This event was a good example of how satellite operators need to be held accountable given the constraints of global best practices, – said the representative of the US Space Force Diana McKissock (Diana McKissock). – They shared their data with each other, contacted, and, I think, in the absence of any global regulation … it was the art of the possible “…
By the way, in September 2019, the European Space Agency (ESA) had to use an evasive maneuver on one of its spaceships at the last minute to avoid a possible collision with the Starlink satellite. The collision probability was 1 in 1000. This may seem like a minor threat, but NASA usually sends ships to the ISS with a collision probability of 1 in 100,000. ESA said it had to relocate its satellite because SpaceX did not have an action plan. SpaceX explained that it missed ESA’s emails about this issue due to a “bug” in its communications systems. Overall, it looks like such dangers will become the norm.
The working satellites have thrusters, but some of them fail and cannot be controlled from Earth. They gradually decrease and burn up in the atmosphere, but, while in orbit, they simply turn into a piece of space debris rotating at a tremendous speed. And if there are thousands of them, it may complicate the launch and exploration of outer space in the future.

One of the satellites of the OneWeb constellation in orbit around the Earth (OneWeb)
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