July 4, 2012: On June 29th the U.S. launched its sixth (since 1995) Mentor electronic reconnaissance satellite. These six ton birds deploy the largest antenna array (over 110 meters in diameter) ever used in a satellite. Details of how Mentor satellites operate is highly classified, but they are known to pick up a large number of electronic signals from ships, aircraft, and ground stations, as well as other satellites. This data undergoes some processing on the Mentor satellite, is then encrypted and transmitted to American ground stations for further analysis.
Little is said about these satellites because, more than photo satellites, these electronic listening birds can potentially pick up anything (radar, radio, whatever) that is broadcast from anywhere. This is an alarming possibility for producers and users of military electronics. Not knowing exactly what those enemy satellites are picking up is very disturbing. China, for example, has launched Cyber War type hacking attacks on American companies involved with collecting and analyzing Mentor satellite data. If the Chinese have reached the Mentor database, it has made Chinese electronics much less likely to encounter unpleasant surprises in wartime.