S82-41171 (29 Nov. 1982) --- NASA?s tracking and data relay satellite (TDRS) is gently mated to its inertial upper stage (IUS), which will propel the satellite to a higher geosynchronous orbit after it is ejected from the Challenger?s cargo bay during STS-6. Another TDRS will be placed in orbit on a later shuttle mission. The two will provide communications between orbiting shuttle mission craft and the ground, resulting in increased real-time communication and eliminating the need for much of NASA?s extensive world-wide system of ground tracking stations. A more distant plan is to launch other TDRS to be used for commercial telecommunications and for handling peak loads. Photo credit: NASA