North Korea launch timing a surprise

The North Korean rocket launch caught the United States by surprise as it occurred earlier than expected, defense and senior U.S. officials said.

Military and intelligence were on heightened readiness for the launch because of intelligence and that North Korea had announced a window, according to a defense official.

One U.S. official disputed the suggestion that the launch was a surprise saying that "North Korea's launch occurred during the anticipated window."

But the general belief was that it would happen around Dec. 17, the defense official explained.

That belief was partly due to Pyongyang's statements about extending the window by a week due to technical problems.

The United States had satellite monitoring of the site. The military also had Aegis radar ships and other monitoring equipment positioned in the region, but mostly to detect the launch and the rocket's trajectory, according to the official.

Blastoff occurred on Wednesday morning from a space center on the North Korean west coast and the rocket apparently delivered a rudimentary communications satellite with limited capability into orbit, the U.S. defense official told CNN.

The satellite is in a Polar orbit meaning it moves between the North and South poles, the official said.