The Orion 3 and 4 (RIO 3, 4) satellites, which are generally known as 'Advanced Orion' or 'Mentor', are geostationary signals intelligence satellites, which replaced the Magnum / Orion series. Their purpose is to intercept missile telemetry from Russia and China and the COMINT capability of the Mercury satellites was merged into this series. These satellites are launched under the designation Program 7600.
Although this satellite series was originally designed for FISINT (Foreign Instrumentation Signals Intelligence), they are now primarily used as COMINT collectors, with about 85% of their work is againt COMINT targets. Some were collocated with Thuraya mobile communications satellites.
These satellites feature a large dish antenna for signal reception, which has reportedly a diameter of ~100 m. The main body has the shape of an octagonal prism, carrying an large array of different antennas, among them a smaller deployable dish. The combination of fixed and steerable feeds allows simultaneous collection againt multiple signal types (COMINT, ELINT, MASINT, etc.) located across a broad geographic aera. The satellites of this series are injected directly into the final orbit by the launch vehicle's upper stage, so they do not feature an apogee propulsion system. These satellites have a significantly larger mass as the first two Magnum / Orion satellites.
Additionally to the SIGINT task, these satellites reportedly also included a communications cross-link system in space and had some limited data relay capability.
These satellites were succeded by the Mision 8300 Orion satellites.
|Type / Application:||SIGINT, ELINT, COMINT|
|Operator:||NRO, CIA, NSA|
|Contractors:||TRW → Northrop Grumman Space Technology|
|Configuration:||Large Dish Antenna, 3-Axis-Stabilization|
|Power:||Solar arrays, batteries|
|Orion 3 (RIO 3, Mission 7607, USA 110)||1995-022A||14.05.1995||CC LC-40||Titan-4(01)A Centaur-T|
|Orion 4 (RIO 4, Mission 7608 ?, USA 139, NROL 6)||1998-029A||09.05.1998||CC LC-40||Titan-4(01)B Centaur-T|