The "Automated Transfer Vehicle" (ATV) was a 1990s-design expendable cargo spacecraft. Each vehicle consisted of two distinct sections, the systems bus and the integrated cargo carrier. The system bus contained the ATV's propulsion system, avionics bays, and solar arrays; it was principally used following the vehicle's detachment from the Ariane 5 launcher to automatically traverse the remaining distance and dock with the ISS, the system bus would be inaccessible to the astronauts on board. The integrated cargo carrier consisted of a pressurised module, external bays for fluid and gas cargoes, further avionics and rendezvous sensors, and the docking mechanism. The primary structure of the ATV is protected by a meteorite and debris protection system.