Clear Orbit Secure Future 2026

1.1 Understanding the model Development of the orbital population model started from a full snapshot of the orbital catalogue as of May 2025, encompassing every known object tracked by the US Space Force and mirrored in the LeoLabs catalogue. Each object is classified into one of three categories: 1Operational satellites functioning payloads 2Intact derelicts inactive satellites and rocket bodies 3Fragments pieces of debris produced by explosions or collisions Using this baseline, the model projects in five- year  increments (2025–2030, 2030–2035 and 2035–2040), updating the population in each step by adding newly launched satellites, newly abandoned derelicts based on observed failure trends and newly generated debris from expected fragmentation events. Each step yields a spatial density map (how many objects exist in each 10 km altitude slice between 300 and 2,000 km) and applies representative assumptions for their size, mass and motion. A typical working satellite is modelled with a 3 m2 cross-section, an inactive rocket body with 8 m2 and 1,400 kg mass and debris fragments with 0.04 m2. Conjunctions and impacts in low Earth orbit occur at roughly 12 km/s, meaning even millimetre-sized fragments can puncture critical spacecraft components. To mimic real-world behaviour, the model also introduces expected fragmentation events, including rocket-body explosions in 2029, 2033 and 2037, each producing roughly 350 new tracked fragments and thousands of small non- trackable ones. For every catalogued fragment (>10 cm), there are an estimated 90 lethal non- trackable (>1–10 cm) pieces and 250 hazardous non-trackable (5 mm–1 cm) pieces, objects too small to track but capable of terminating or degrading a spacecraft’s mission. Clear Orbit, Secure Future: A Call to Action on Space Debris 8