These satellites at
geostationary orbits collect radio emissions (
SIGINT) and act as replacements for the older constellation of
Magnum satellites. The satellites have estimated mass close to 5,200 kg and very large (estimated 100 m diameter) radio reflecting dishes.
USA-223 (NROL-32), which is seen as the fifth satellite in the series, is according to NRO director
Bruce Carlson "the largest satellite in the world." It is believed that this refers to the diameter of the main antenna, which might be well in excess of . The mission and capabilities of these satellites are highly
classified, though targets may include telemetry,
VHF radio, cellular mobile phones, paging signals, and mobile data links. Earlier satellites with similar missions, the
Rhyolite/Aquacade series, were built by
TRW; it is not known who made the Orion satellites. File:USA202 Mentor4.jpg|USA-202 shows up as a
magnitude +8 "star" in this image. Note how the real stars are trailed in this 10-second exposure: the geostationary satellite is pinpoint. File:NROL-32b_ULA_21NOV2010.jpg|USA-223 (NROL-32), the fifth "Mentor" satellite, atop a Delta IV rocket File:USA202_Thuraya2.jpg|USA-202 and the nearby commercial geostationary satellite
Thuraya 2 == Satellites ==