Delta 4-Heavy rocket rolls out at Vandenberg

United Launch Alliance and the Air Force are readying the next Delta 4-Heavy rocket, the largest booster in the U.S. arsenal that is responsible for launching the nation's elite surveillance satellites. The rocket was rolled from its Horizontal Integration Facility to the Space Launch Complex-6 pad at Vandenberg Air Force Base on April 29 and went vertical on April 30.

See our full story on the rollout.

Photo Credit: United Launch Alliance