The European Space Agency (ESA) has raised alarms regarding the health of the space environment, revealing a concerning status in its newly published Space Environment Health Index. Currently rated at level 4, this index significantly exceeds the sustainability threshold, prompting the agency to call for urgent and more rigorous measures to safeguard the future of space activities.
As congestion and pollution in Earth”s orbit worsen at a rapid pace, the need to quantify the effects of human behavior on the orbital environment becomes increasingly critical. In response, ESA has introduced the Space Environment Health Index in its Annual Report on the Space Environment, which summarizes the state of outer space in a single metric over time.
“The Space Environment Health Index is an elegant approach to link the global consequences of space debris mitigation practices with a quantifiable impact on the space debris environment,” stated Stijn Lemmens, an analyst specializing in space debris mitigation at ESA. “With this new metric, ESA promotes a common language to assess the impact of our space activities and to make the consequences tangible.”
To ensure a safe and sustainable space environment, there is a pressing need for an effective measure of its overall health and to quantify the impact of each new mission. Just as climate scientists use temperature as a key indicator of global warming, the space community requires a clear and quantifiable metric to evaluate the impact of objects and missions on orbital sustainability.
The Space Environment Health Index provides such a metric, offering a unique score that reflects the degree of health or stress within the orbital environment and its repercussions over a span of 200 years. While a single number cannot encompass all complexities, it will provide a useful overview of the space environment”s status, facilitating high-level discussions. Furthermore, it will serve as a framework for assessing the impact of each mission on the overall condition of space.
This index supports global sustainability efforts, including ESA”s own Zero Waste approach, which aims to eliminate waste generation from ESA missions by 2030.
