A reusable crewed orbital transportation system. The space shuttle, along with crewless (robotic) expendable launch vehicles such as Atlas and Delta, make up the United States Space Transportation System (STS). The shuttle provides the unique capability for in-flight rendezvous and retrieval of faulty or obsolescent satellites, followed by satellite repair, update, and return to orbit or return to Earth for repair and relaunch. The space shuttle also plays an essential continuing role in the construction and provisioning of the International Space Station (ISS) by transporting major components, such as the giant solar-cell arrays and the Canadian computer-driven double-ended robotic arm, from Earth to the ISS and installing them using extended extravehicular activity (EVA, or space walks) by trained ISS resident and shuttle-visiting astronauts.