Sustainable Space

As our reach extends outside our planet into Earth’s orbital space and beyond, the need for proactive research and equitable governance of human activity in outer space is more urgent than ever.

The rapid launch of hundreds of thousands of satellites into low Earth orbit will significantly alter our view of the sky and raise concerns about the sustainability of Earth’s orbital space. A new framework for sustainable space development must balance technological advancement, protection of space environments and our capacity to explore the Universe.

Earth Observation (EO) satellites have transformed understanding of the state and trajectories of Earth’s environment. Recent mushrooming of EO satellites and of resultant data that are stored, distributed and processed, often on the cloud, generate widespread environmental impacts that demand urgent consideration, particularly given that EO data outlive EO satellites.

Research on how to support human exploration and eventual habitation of outer space is advancing. However, while its aims are beyond our planet, space bioprocess engineering has practical sustainability applications here on Earth.

Crowded with satellites and debris, the orbital space around the Earth should be formally recognized as an ecosystem—like the ocean and the atmosphere—to ensure sustainable development and protection from irreversible damage.

Rocket emissions and debris from spacecraft falling out of orbit are having increasingly detrimental effects on global atmospheric chemistry. Improved monitoring and regulation are urgently needed to create an environmentally sustainable space industry.

Each uncontrolled rocket body in orbit poses a low casualty risk on reentry. But the cumulative risk is unacceptable and disproportionately borne by the Global South. Spacefaring states must stop exporting these risks and plan for safer reentries.

Astronomical research facilities, such as space telescopes, space probes or ground-based observatories, are the largest contributor to an astronomer’s carbon footprint, well beyond other activities such as flying to conferences or running computer simulations.

We report the outcome of an international optical observation campaign of a prototype constellation satellite, AST SpaceMobile’s BlueWalker 3, which features a 64.3 m² phased-array antenna and a launch vehicle adaptor.