Space traffic experts suggest in a new report that world leaders safeguard the increasingly crowded confines of low Earth orbit by establishing a system similar to the aviation industry’s volume-based Class A, Class B and Class C approach.
“The Airspace Class system aviation effectively manages traffic volume and complexity by establishing specific entry requirements for different airspace volumes,” said the October 2024 paper presented by Mitre, a federally funded technology research and development group. “Similarly, an orbital classification system can enhance space safety and sustainability by tailoring requirements to the unique characteristics and capabilities of objects operating at various altitudes.”
The authors suggest a “LEO Class” system with five categories, starting at Class E, below manned spaceflight, and rising in order of altitude to Class A, congested; Class C, occupied; Class B, persistent; and Class D, lightly occupied. The U.S. airspace classification chart, by contrast, ranges from Class A to Class G and contains dozens of subcategories.
The paper is titled “Integrating Orbital Carrying Capacity into International Policy Constructs: Leveraging best practices from aviation’s risk-based norms,” and was presented at the 75th International Astronautical Congress in Milan, Italy. It identifies the six “neighborhoods” of low Earth orbit popularized by co-
author Darren McKnight with space tracking company LeoLabs.
These include the “Starlink Corridor” at 500 kilometers to 600 kilometers, where 40,000 Starlink satellites are planned by SpaceX alone but where spacecraft are actively managed for safety, and the corridor at 900 kilometers to 1,100 kilometers that’s dubbed Highest Collision for all of the uncontrolled old Russian rocket bodies there.
“The number of satellites alone is not an adequate measure of orbital risk,” the paper said. “It is important to factor the size, mass, maneuverability, and lifespan of the satellites in a particular orbit.”