Certain valuable orbits may become unusable because of unsustainable levels of space debris concentration. Orbits that may be most affected are essential today for meteorology, climate research and disaster and environmental management, in addition to commercial and military applications. Satellites provide unique and irreplaceable observations. The growing risks linked to busy and crowded orbit are possible irreversible chain reactions of in-orbit collisions, the so-called Kessler Syndrome.

Addressing this issue will require stronger and more coordinated public-private collaboration, for example on data-sharing, international consensus on standards and best practices, technological development, and innovative policymaking supported by new economic instruments to increase satellite operators’ compliance. The OECD supports current efforts by providing new evidence on the economics of space sustainability.

Space activities can generate negative environmental effects on Earth and in the atmosphere, including stratospheric ozone depletion, air acidification, smog, toxic waste spills, water pollution, noise pollution, water consumption, and various types of material demands which can contribute to resource depletion. The growth in space activities also creates new light pollution impacting astronomical research. Existing satellites and debris already exceed the threshold of acceptable light pollution at astronomical observatory sites. The increased satellite traffic in the low-earth orbit is also problematic for radio astronomy, traditionally protected by “radio quiet zones” because it collects extremely weak and sensitive signals.

There is growing awareness within the sector to address these issues, but lacking observational data and limited access to industry data makes it more challenging to adequately identify and assess the full environmental impact of space activities. The OECD Space Forum conducts research on these issues to support the development of new evidence-based policies.

Growing evidence supports the “case for space”, documenting how space activities can have positive impacts on our societies, leading to ever more countries investing in space technologies for strategic and economic reasons. But certain inherent characteristics of the space sector, such as its limited visibility in official statistics, sensitive dual-use technologies developments, geopolitical considerations and industrial confidentiality make efforts to track externalities more challenging.

Governmental agencies and the private sector should not shy away from collecting more evidence on the positive and negative effects of conducting space activities. There is a need for more internationally comparable data, as well as to make better use of existing data through more transparency and data-sharing. This will support concrete orbital debris mitigation approaches and lead to more transparency on industrial practices.