Mega-constellations in low-earth orbit are both a connectivity revolution and a threat to astronomy. Discuss, and suggest a regulatory framework that balances the two.

Low-earth orbit (LEO) mega-constellations such as Starlink, OneWeb and China's Guowang promise broadband anywhere on earth. But a study in Monthly Notices of the Royal Astronomical Society, based on the SNIFFLES monitoring programme, found that their radio emissions interfere with radio astronomy [1]. The task is to balance the two, not to choose between them.

Connectivity revolution

• Last-mile reach: serves villages, ships, Himalayan and border areas where laying fibre is not viable.
• Direct-to-cell services connect ordinary phones straight to satellites [1]. This helps disaster response and Digital India.
• Low latency compared with geostationary satellites supports telemedicine, e-learning and strategic communication.

Threat to astronomy

• Signal strength: some emissions were 100 billion times brighter than typical cosmic sources, strong enough to blind receivers [1].
• Lost science: a OneWeb signal at 1,613.19 MHz overlaps the hydroxyl line used to map star-forming gas [1].
• Persistent leakage: one Starlink version emitted stray radiation in about 77% of observations over ~376 hours [1].
• Regulatory gap: licences cover intended transmissions and limit unwanted ones (harmonics). Unintended radiation from power converters and onboard computers falls outside any spectrum licence [1].
• Remote sites no longer protect: Australia's Mopra and ATCA telescopes still picked up the signals [1]. India's GMRT faces satellites India never licensed.

A balancing regulatory framework

• Global: turn the UN Dark and Quiet Skies recommendations to COPUOS [2] into binding emission limits on satellite hardware. This would build on Article IX of the Outer Space Treaty, which requires states to avoid harmful interference.
• ITU: extend the Radio Regulations from transmitters to unintended radiation. Protect radio-quiet zones around observatories such as GMRT and SKA.
• National: IN-SPACe and DoT should require pre-launch test data on stray emissions before authorising operators. Shielding can only be added before launch.
• Operators: steer beams away from telescopes and share satellite-position data so astronomers can plan around passes.

Mega-constellations and astronomy share one radio sky, but the conflict is about engineering discipline, not connectivity itself. Pre-launch emission standards, binding multilateral rules and data-sharing can deliver universal access (SDG 9) and keep the sky open for science as a true global commons.