(www.mda.mil)

The Space Tracking and Surveillance System  is a new system by the MDA that will allow more precise tracking of ballistic missiles in orbit. It provide information on both ballistic and tactical missile. The first satellite that will be part of the STSS was delivered to the Air Force in June 2009 and is expected to be launched by the end of 2009.

STSS provides a number of improved and new functions to the missile tracking system. It operates in low earth orbit and can begin tracking missiles in the boost phase. It can then continure to track the missiles throughout the midcourse phase of flight. This is a majr obstacle as the missiles in midcourse no longer have a major heat signiture from the firing engine. This makes them much more difficult t track though a cool atmosphere. The system uses infrared sensors to track the missiles. In addition to its tracking capabilities, it will play a role in discriminating between missiles and decoys.

Anywhere from nine to 30 satellites may eventually be in orbit. The greater the number, the greater the coverage, with 30 providing coverage worldwide.