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.^[4]

TDRS-11 was constructed by Boeing, and is based on the BSS-601HP satellite bus. Fully fuelled, it has a mass of 3,454 kilograms (7,615 lb), and is expected to operate for 15 years.^[1] It carries two steerable antennas capable of providing S, Ku and Ka band communications for other spacecraft, plus an array of additional S-band transponders to allow communications at a lower data rate with greater numbers of spacecraft.^[4]

TDRS-11 was launched at 01:48 UTC on 31 January 2013, at the beginning of a 40-minute launch window. United Launch Alliance performed the launch using an Atlas V carrier rocket, tail number AV-036, flying in the 401 configuration.^[5] Liftoff occurred from Space Launch Complex 41 at the Cape Canaveral Air Force Station, and the rocket placed its payload into a geostationary transfer orbit.

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.^[6] As of May 2020, it was positioned at 174 degrees west.^[7]

• List of TDRS satellites