Is outer space a global commons? Examine in the context of satellite broadband and the scientific use of the radio sky.

The Outer Space Treaty, 1967, declares space the "province of all mankind" (Art. I) and bars national appropriation (Art. II) [3]. In law, space is a global commons. In practice, mega-constellations are turning its orbits and radio spectrum into a crowded, commercially exploited resource.

Why space qualifies as a commons

• Non-appropriation and free access: no state can claim sovereignty over orbits [3].
• Due regard: Article IX requires consultation before activities causing harmful interference to others [3].
• Shared but finite: orbits and spectrum are open to all yet limited, the classic commons profile.

Satellite broadband: commons under commercial pressure

• LEO constellations (Starlink, OneWeb, China's Guowang) extend broadband and direct-to-cell service to remote areas [1].
• Each is licensed by one state, yet its satellites pass over every country [1]: national licensing, global spillover.
• Emissions go beyond licensed bands: harmonics (unwanted) and stray radiation from power converters and computers (unintended) [1].

Radio sky: science as the crowded-out user

• Australia's SNIFFLES programme tracked satellites for ~376 hours and found some signals 100 billion times brighter than cosmic sources [1].
• A OneWeb emission at 1,613.19 MHz overlaps the hydroxyl line used to map star-forming gas [1]. A spectral line cannot be relocated.
• One Starlink version emitted in ~77% of observations [1], pointing to a design trait, not a fault.
• Remote "radio-quiet" sites cannot help when interference comes from overhead. This is a negative externality borne by public science, including India's GMRT.

Where the commons label falls short

• Soft law only: the UN–IAU Dark and Quiet Skies process yielded recommendations, not binding rules [2].
• Weak enforcement: Article IX offers consultation, not emission limits [3]; consensus-based COPUOS lets one space power stall binding norms.
• Tragedy of the commons: voluntary shielding raises costs, so compliant operators lose out to free-riders.

Outer space is thus a global commons in law but an open-access frontier in practice. Commercial broadband is crowding out science. The remedy is managing the commons, not curbing connectivity: binding hardware-emission limits through COPUOS and the ITU, pre-launch emission testing in national authorisation (for instance by IN-SPACe), and protected radio-quiet zones. Such stewardship would give real meaning to the Treaty's "province of all mankind".