A mega-constellation is a satellite network of hundreds to tens of thousands of spacecraft, almost always in low Earth orbit, designed to provide global services such as broadband internet. SpaceX's Starlink (12,000+ authorized, 42,000 requested), Amazon's Project Kuiper (3,236 planned), and OneWeb (648 satellites) are the most prominent examples. The sheer number of satellites provides continuous, low-latency global coverage.
Mega-constellations have raised significant concerns about space sustainability. The orbital debris risk, light pollution for ground-based astronomy, radio frequency interference, and the challenge of managing thousands of objects in busy orbital corridors are all active areas of regulatory and technical debate. Responsible operators build in autonomous collision avoidance and guaranteed deorbit capabilities.