CAPE CANAVERAL, Florida - The Air Force has launched a new classified spy satellite.

An un-manned Delta 4-Heavy rocket blasted off From Cape Canaveral Air Force Station on Sunday at 5:58 p.m. (2258 GMT)

It carried a satellite that was described in a news release from the National Reconnaissance Office as "the largest satellite in the world."

The mission is classified, so no other details are available.

The 23-story rocket took off after several delays over the past few months because of technical glitches, including a problem during fueling for a launch on Friday. Weather concerns on Sunday cleared shortly before launch time.