Casualty risk on the ground – 2026 Space environment report

Evolution of the estimated on-ground casualty risk from uncontrolled reentries.

A new metric introduced in the 2026 report highlights the growing casualty risk on the ground from fragments that survive atmospheric reentry. While the probability of a casualty remains low compared with many everyday risks, the upward trend reflects the cumulative effect of more launches, more satellites and more reentries.

The casualty risk is computed leveraging the observed correlation between spacecraft mass and casualty area. This correlation was built starting from the data over more than 100 spacecraft for which a detailed reentry risk analysis was performed (see figure D in ESA Space Debris Mitigation Compliance Verification Guidelines).

A reduction in risk might be achieved through more controlled reentries of payloads and the wider adoption of design-for-demise technologies, which ensure satellites burn up as completely as possible during reentry.

Discover the 2026 ESA Space Environment Report.