TDRS-11, known before launch as TDRS-K, is an American communications satellite which is operated by NASA as part of the Tracking and Data Relay Satellite System. The eleventh Tracking and Data Relay Satellite is the first third-generation spacecraft. Following its arrival in geosynchronous orbit, the satellite underwent on-orbit testing. It was handed over to NASA in August 2013, receiving its operational designation TDRS-11. After its arrival on-station at 171 degrees west the satellite began its final phase of testing prior to entry into service at the end of November.