Northrop Grumman Aerospace Systems Sector on Jan. 19 said the pair of unclassified Space Tracking and Surveillance System (STSS) demonstration satellites it built for the U.S. Missile Defense Agency are ready to fully participate in ballistic missile defense tests following successful on-orbit calibration of the spacecrafts’ acquisition and tracking sensors.
Northrop Grumman said the sensor calibration was completed last November, marking the final major step in the satellites’ lengthy on-orbit commissioning. The U.S. Air Force launched the two STSS satellites aboard a Delta 2 rocket in September 2009 from Cape Canaveral Air Force Station, Fla.
In a separate announcement Jan. 18, Northrop Grumman said it and sensor payload provider Raytheon Co. had expanded the effectiveness of the STSS satellites by successfully activating a communications crosslink between them.
Doug Young, Northrop Grumman vice president for missile defense and warning programs, said in a statement that the radio frequency relay between the two missile defense satellites enables communications with one spacecraft that is out of view of a ground station when the other satellite is in range.
“The crosslink expands the regions of the world where both satellites are in communication, enabling closure of the fire control loop with missile defense interceptors,” Young said.