The word “space traffic management” (STM) invariably conjures up images of air traffic control. It brings up images of controllers staring at screens, directing spacecraft to avoid collisions in the same way that air traffic controllers operate with planes. The truth is rather different. Unlike satellites, defunct aircraft do not linger in airspace for decades or years. Aircraft can also maneuver, something that debris and some satellites lack. And, to direct air traffic, the air traffic controllers have explicit authority on the national level and collaborate worldwide.

As a result, individuals working in space traffic management recognize that the name is a misnomer. In a lecture at the Advanced Maui Optical and Space Surveillance Technologies (AMOS), event in Hawaii in the mid-September, US Space Force Maj. Gen. DeAnna Burt, head of the Combined Force Space Component Command of US Space Command, said: “A lot of time we talk about space traffic management.” “I believe we are aware of space traffic.”

The difference, she explained, is that groups like the Space Force’s 18th Space Control Squadron monitor objects and predict probable collisions, but they don’t have the authority to prevent them. When the two things are debris, this is definitely the case. She admitted, “Those are tough days.” “We’ll get to see two dead objects perhaps crash, and then we’ll tell what happened,” says the narrator.

If either one or even both of the satellites are operating, Burt said she doesn’t have much more authority. “If that object isn’t a US-flagged Department of Defense asset, I’m alerting them to the fact that there’s a collision, and it’s up to them what they do,” she said. “We don’t have the power or the authority to instruct them what to do.”

Without the need for a space traffic control agency to direct satellite maneuvers, satellite operators must decide whether as well as how to maneuver their spacecraft to avoid any collisions. Operators are clearly driven to avoid collisions, not only due to the debris that they produce, but also because of the money lost if a spacecraft is damaged or destroyed.

When an active satellite is threatened by a piece of the debris, the scenario is simple: the satellite operator must decide whether the danger of collision is substantial enough to justify a maneuver, assessing that risk against the cost of propellant utilization, which reduces the satellite’s lifetime, and any service disruption caused by maneuvering. While the strategy is simple, it isn’t always followed. Research presented at AMOS by the commercial space situational awareness (SSA) provider COMSPOC Corp. showed no agreement among major satellite operators on the criteria they employ to decide whether to undertake a collision-avoidance maneuver.

COMSPOC collaborated with Space Data Association, a collection of satellite operators who exchange SSA data, to figure out what parameters’ corporations use to assess whether a close encounter is too near for comfort. For example, geostationary satellite operators employed criteria ranging from 1,000 – 15,000 meters for potential miss distances and 1 in 10,000 to about 1 in 1 billion for the probability of collision.

Leave a Reply

Your email address will not be published. Required fields are marked *