Giove B, also known as GIOVE-B (Galileo In-Orbit Validation Element-B), is the second test satellite of the Galileo navigation system, Europe's own global navigation satellite system (GNSS). Giove B played a crucial role in the Galileo program by validating key technologies and system designs that would be used in the operational Galileo satellites. It helped refine the performance and reliability of the navigation system, contributing to the overall success of Galileo.