A Nanosatellite 3U refers to a specific type of small satellite that falls under the broader category of “nanosatellites“.
A 3U nanosatellite is typically a cube-shaped satellite measuring 10x10x30 centimeters, with a mass ranging from 1 to 10 kilograms. The “3U” designation refers to the number of “Units” the satellite takes up, where each “Unit” is equal to 10x10x10 centimeters in size. So a 3U satellite takes up three of these units stacked on each other.
Despite their small size, Nanosatellites 3U can perform a wide range of tasks and are relatively low-cost and quick to develop. They can be launched into space as secondary payloads on rockets carrying larger satellites or as part of a larger constellation of satellites.