Issue 91

Dec 2023: Robin Dickey from the Aerospace Corporation’s Center for Space Policy and Strategy released her paper looking into the potential use of the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs) to help create basic rules of the road for space. She notes the COLREGs contain several rules and principles that could be adapted to help identify collision risks in a conditions-based approach, make decisions on which satellites should maneuver to avoid collision, and facilitate communication between operators to resolve confusion or disagreements. Below is an excerpt from her most excellent 18-page paper (which you should read).

– In other domains, rules of the road help operators make decisions and take action to avoid collision, but these rules do not exist yet for space.

– Policymakers…may need to consider the approach of drawing lessons from other domains. Such analogies can take concepts from norms or rules that already work in one environment and translate them to the physical and legal context of space.

– COLREGs is a uniquely useful document to analogize to space because, unlike broader treaties such as the UN Convention of the Law of the Sea, COLREGs focuses exclusively on guidance for avoiding collisions.

-COLREGs exists in a legal environment that is more comparable

to space than the air domain…both sea and space include vast swaths of the domain where no national actor has sovereignty or responsibility and collision-avoidance decisions are up to the individual operators.

– COLREGs provides guidance for how to operate in a low visibility environment, highlights multiple paths for communication, and gives directions on how to respond if other safeguards fail, all of which could make similar situations in space less dangerous.

– COLREGs do not attempt to define a “safe distance” or a “safe speed.” Those terms are mentioned but are not assigned a specific number. Instead, the convention establishes a series of criteria to help the operators of vessels decide which situations are at high risk of collision or not…Many of these conditions are directly translatable to relevant concerns in space. Just like mariners, space operators must contend with problems related to “visibility,” maneuverability, and environmental hazards.

-The COLREGs conditions-based approach…complements the metric used to determine collision risk in space today. Operators currently look for a probability of collision based on where and when the paths of two space objects are expected to intersect and the margin of error for their predictions.

– COLREGs provides a multifaceted approach to determining right of way.

– The Space Safety Coalition updated its “Best Practices for the Sustainability of Space Operations,” including a matrix of which spacecraft should move to avoid a potential collision. There are five categories: (1) non-maneuverable, (2) minimally maneuverable, (3) maneuverable, (4) automated collision avoidance, and (5) crewed.

– Parts of the space community are already drawing from right-of-way models similar to what is established in COLREGs