Mercury-17 (NROL-7)

The Mercury (MC) series, although known to the public as 'Advanced Vortex', are the latest generation of USAF ELINT/SIGINT satellites. They were focussed on communications intelligence (COMINT), focused at strategic level communications, but had the capability added to intercept also missile telemetry. These satellites were launched under the designation Mission 7500 and were part of NRO's Program A.