Health Index – 2026 Space environment report

The Space Environment Health Index projects the total effect of satellites’ individual impact over time, normalised against the target of a sustainable environment as established in 2014. 

Just as climate scientists use temperature as a key indicator of global warming, the space community needs a clear, quantifiable metric to assess the impact of objects and missions on orbital sustainability. 

The Space Environment Health Index provides such a metric. It is a single score that reflects how healthy or stressed the orbital environment is and what the consequences will be. In 2014,  a reference scenario, based on high level of implementation of space debris mitigation measures, was defined and it is adopted here as a benchmark for an acceptable evolution of the debris environment. Anything above means that there will be that many times more strain on the orbital environment than is sustainable.  

The incredibly large jump of the Index from about 4 to 50 in just one year means that the already beyond sustainable effects of our space activities has worsened an entire order of magnitude in just one year’s time.  

Discover the 2026 ESA Space Environment Report.