小型卫星星座

The concept of a satellite constellation is not new; the GPS system is a prime example. However, the ‘NewSpace’ revolution has been defined by mega-constellations composed of hundreds or thousands of small satellites in Low Earth Orbit (LEO). This architecture is fundamentally different from traditional geostationary (GEO) satellites. While a single GEO satellite can cover a large region, LEO satellites have a much smaller field of view and move rapidly across the sky. Therefore, a large number must be used in concert to provide continuous coverage.

This approach offers several advantages. The low altitude reduces signal latency, which is critical for applications like broadband internet. The high number of satellites provides high temporal resolution, or ‘revisit rate’, allowing for near-constant monitoring of the Earth’s surface. Furthermore, the system is resilient; the failure of a single satellite has minimal impact on the overall service. The primary challenge is deployment and maintenance. Launching thousands of satellites is a massive logistical and financial undertaking. On-orbit management requires sophisticated automation for station-keeping, collision avoidance, and de-orbiting at the end of life to mitigate the growing problem of space debris. For communications constellations, inter-satellite links (often using lasers) are necessary to route data around the globe without relying on ground stations.