An updated version of the space safety document, approved by more than two dozen organizations, includes “rules of the road” for avoiding collisions with space objects. The updated Space Operations Sustainability Best Practices document, released April 4 by the Space Security Coalition (SSC), is a major revision of satellite operators’ guidance on minimizing the risks of collisions in orbit.

One of the biggest changes in the document is the inclusion of traffic rules to coordinate maneuvers between facilities. The report identifies five classes of objects – non-maneuverable, minimally maneuverable, maneuverable, automatic collision avoidance objects and manned spacecraft – and outlines the rules they must follow when performing a maneuver to avoid a collision, including two of them.

Generally, maneuvers are given priority in favor of more advanced spacecraft, unless otherwise agreed. For example, if a maneuverable spacecraft with automatic collision avoidance collides, the latter will maneuver. Special coordination may be required if two spacecraft of the same category collide.

The rules outlined in the report stem from governments’ interest in enacting similar mandatory rules in national regulations. “They want to develop traffic rules, but they don’t actually operate satellites, so they don’t have a clear idea of ​​which traffic rules will be at least commercially effective,” said Dan Oltrogge, founder and director of the Space Safety Coalition, in an interview.

He noted that many commercial satellite operators have coordinated among themselves and that the rules outlined in the document are based on this experience. “We came up with this approach to have something we can build on but have the essentials.”

The rules are somehow modeled on “give way” maritime rules, where smaller, more maneuverable boats will act to avoid larger vessels that can’t change course so quickly. He noted that one difference is that it may be more difficult to tell when a spacecraft is maneuvering because data about its orbit may not be updated as quickly. These rules do not replace the coordination between operators. “We can set all the traffic rules we want, but if we don’t emphasize coordination above all, we will miss the ferry,” Oltrogge said.

Traffic rules aren’t the only changes in the document. It specifically urges satellite operators to avoid deliberate fragmentation resulting from Russia’s 2021 anti-satellite weapons tests. “There are many strong opinions on avoiding deliberate fragmentation through impact, explosion, or simply released debris,” he said.

It refers to updated international guidelines and standards for space sustainability and debris prevention, as well as cyber security to prevent unauthorized access. There are updated guidelines for the destruction of spacecraft after missions, including the increased reliability of such efforts and the time it takes to “passigate” the spacecraft to prevent debris-forming explosions.

Since the publication of the updated version, the document has been supported by 27 companies and organizations. Major GEO satellite operators include Inmarsat, Intelsat and SES, and LEO satellite operators Iridium and Planet.

“These best practices make clear the desired goals to encourage all space actors to move towards a safer, more responsible and sustainable use of space,” said Charles Lowe, senior flight dynamics manager at SES. “Importantly, these best practices aim to avoid deliberate collisions and debris, and it’s encouraging to see a framework for sharing coordination and orbital information between maneuvering satellites.”

Oltrogge noted that 60 organizations have approved the old version of the guide and the SSC is working to get them and others to sign the new version. “I know a few operators who are actively looking and are likely to sign very soon,” he said. He described the report as a living document that will continue to change. “Maybe I’ll get some rest,” he said, “but space moves so fast we can’t really afford to breathe.”