Outer space

Delta IV Heavy blasts off from Cape Canaveral with spy satellite

A U.S. spy satellite thundered toward orbit Saturday afternoon atop the most powerful rocket flying today, a 23-story Delta IV Heavy that blasted off from Cape Canaveral Air Force Station at 1:51 p.m.

Firing engines from three boosters strapped together, the United Launch Alliance rocket rumbled from its Launch Complex 37 pad with more than 2 million pounds of thrust, rising into low, puffy clouds before threading a white contrail through patches of blue sky.

The triple-bodied rocket — only the ninth flown since its debut in 2004 — and its National Reconnaissance Office intelligence payload flew southeast over the Atlantic Ocean, believed headed for a high orbit more than 22,000 miles over the equator.