Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida .

Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the first half of the two-part fairing is in place around the Space Tracking and Surveillance System – Demonstrator spacecraft. The fairing is a molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. STSS Demo is a space-based sensor component of a layered Ballistic Missile Defense System designed for the overall mission of detection, tracking and discriminating ballistic missiles. STSS is capable of tracking objects after boost phase and provides trajectory information to other sensors. It will be launched by NASA for the Missile Defense Agency between 8 and 8:58 a.m. EDT Sept. 18. Approved for Public Release 09-MDA-4934 (09-22-09) Photo credit: NASA/Cory Huston