ROUGH CUT - NO REPORTER NARRATION
An unmanned Atlas 5 rocket carrying a small robotic space shuttle lifted off from Cape Canaveral Air Force Station in Florida on Tuesday (December 11) for the third flight in a classified military test program.
The 196-foot (60-meter) rocket blasted off at 1:03 p.m. ET (1603 GMT) carrying the military's original X-37B experimental space plane, also known as an Orbital Test Vehicle, or OTV.
The unmanned, reusable space shuttle, one of two operated by the U.S. Air Force, spent 224 days circling Earth during its debut mission in 2010. A sister ship blasted off in 2011 and landed itself after 469 days in space, completing the second orbital test flight.
The military is not saying how long the third X-37B mission will last, nor what the vehicle will be doing in orbit.
U.S. military's secret mini-shuttle lifts off from Florida (1:26)
Dec. 11 - An unmanned Atlas rocket carrying a military experimental space plane lifts off from Cape Canaveral Air Force Station. Rough Cut (no reporter narration). ( Transcript )