USA-200

USA-200, also known as NRO Launch 28 or NROL-28, is an American signals intelligence satellite, operated by the National Reconnaissance Office. Launched in 2008, it has been identified as the second satellite in a series known as Improved Trumpet, Advanced Trumpet, or Trumpet follow-on; a replacement for the earlier Trumpet series of satellites.

USA-200 was launched by an Atlas V launch vehicle, flying in the 411 configuration, operated by United Launch Alliance. The launch vehicle was the first Atlas V to launch from Vandenberg Air Force Base, flying from Space Launch Complex 3E. Liftoff occurred at 10:02 UTC on 13 March 2008. It was identified as NRO Launch 28, and was the thirteenth flight of an Atlas V. The launch vehicle had the tail number AV-006.

The satellite's orbit and mission are officially classified, however like most classified spacecraft it has been located and tracked by amateur observers. It is in a Molniya orbit with a perigee of 1,112 km (691 mi), an apogee of 37,580 km (23,350 mi), and 63.56° of orbital inclination and 684.33 minutes of orbital period.

In addition to its SIGINT payload, USA-200 also carries two secondary instruments; the SBIRS-HEO 2 missile detection payload as part of the Space-Based Infrared System programme, and NASA's TWINS-2 or TWINS-B magnetospheric science instrument as part of the TWINS programme.