Satellites Used to Have Months to Avoid Collisions–Now They Have Days
7 hours ago
- #satellite-collisions
- #CRASH-clock
- #space-debris
- Earth's orbit is increasingly cluttered with space debris from rocket launches, defunct satellites, and anti-satellite tests.
- The rise of mega constellations like SpaceX's Starlink has drastically reduced the time to avoid collisions, from months to less than a week.
- The CRASH Clock, a new measure, shows the shrinking reaction window for satellites to avoid dangerous close passes or collisions.
- As of June 2025, the CRASH clock value was about 5.5 days, down from 164 days in January 2018.
- Satellites in low-Earth orbit now face a 17% chance of a close approach that could lead to a collision within 24 hours.
- Communication issues and solar storms can hinder quick evasive maneuvers, as seen in a 2019 near-miss between ESA and Starlink satellites.
- The Kessler-Cour-Palais Syndrome describes the growing risk of cascading space debris collisions due to increasing satellite launches.
- Over 9,000 active Starlink satellites make up about two-thirds of all active satellites, with competitors like Amazon's Project Kuiper adding to the congestion.
- Future projects like orbital space mirrors and data centers could further complicate space traffic management.
- Coordinating collision avoidance among many independent organizations with differing tools and information-sharing practices is a major challenge.