Small satellites (smallsats) broadly encompass any spacecraft under 500 kg, including nanosatellites (1-10 kg), microsatellites (10-100 kg), and minisatellites (100-500 kg). The smallsat revolution has been driven by miniaturization of electronics, commercial off-the-shelf components, and dramatically reduced launch costs. Planet Labs operates the largest commercial smallsat fleet, with over 200 Dove and SuperDove imaging satellites each weighing approximately 5 kg.
Smallsats now perform missions spanning Earth observation, weather monitoring, ship tracking (AIS), aircraft tracking (ADS-B), IoT connectivity, spectrum monitoring, and synthetic aperture radar. The technology has fundamentally shifted the space industry from a model of few, large, expensive satellites to many, small, affordable ones that can be rapidly replaced and upgraded.