The U.S. Missile Defense Agency (MDA) has handed over control of a classified missile tracking demonstration satellite to Air Force Space Command, the MDA announced Feb. 26.

The MDA’s Space Tracking and Surveillance System (STSS) Advanced Technology Risk Reduction spacecraft was launched in May 2009 and successfully completed its test program, the press release said. In addition, it has been used to conduct space situational awareness activities, which Air Force Space Command will continue on an as-needed basis, it said.

The spacecraft was built by Northrop Grumman Aerospace Systems of Los Angeles, which also built two unclassified STSS satellites that launched a month later. The two unclassified satellites completed their calibration period in November and are ready to participate in ballistic missile defense tests, according to a Jan. 19 Northrop Grumman press release.