Atlas V, secret satellite poised for launch

What may be a first-of-its-kind US spy satellite is set to lift off atop an Atlas V rocket.

The countdown from Cape Canaveral Air Force Station is set to begin after a more than two-week delay because of damage to an Air Force tracking radar needed to ensure public safety during the flight. The 19-story United Launch Alliance rocket and its classified National Reconnaissance Office payload returned to their Launch Complex 41 pad, repeating a trip they made March 24, the same day an electrical short disabled the tracking radar located on Kennedy Space Center.

Amateur astronomers who make a hobby of tracking satellites, including secret missions, suspect the payload is a signals intelligence, or SIGINT, satellite bound for a geosynchronous orbit more than 22,000 miles above the equator.

Signals intelligence satellites are designed to detect transmissions from broadcast communications systems such as radios, as well as radars and other electronic systems, according to an overview from the Federation of American Scientists.