The Space Tracking and Surveillance System - Demonstrator. or STSS-Demo Program.
is a space-based sensor component of an evolving ballistic missile defense system.
Consisting of two satellites launching together.
the STSS Demo payload is designed to test new technology for missile detection.
tracking and discriminating ballistic missiles.
Owned by the U.S. Missile Defense Agency. the payload's two satellites were
successfully launched from Cape Canaveral Air Force Station
aboard a United Launch Alliance Delta II rocket on Sept. 25. 2009.
The vehicle's main engine and six solid rocket motors provided a combined thrust
of nearly 800.000 pounds as the rocket accelerated to the sky.
toward orbit nearly 840 miles above Earth.