A Delta IV rocket roared off the launch pad at Vandenberg Air Force Base on Tuesday afternoon, carrying a classified reconnaissance satellite into Earth orbit.

The 200-foot-plus rocket left the launch as scheduled at about 4:12 p.m., according to United Launch Alliance, a joint venture of Lockheed Martin and the Boeing Co. that is in charge of the mission.

Launch officials had indicated earlier in the day that there was a 40-percent chance of favorable weather conditions for the launch, which was visible from various areas throughout the Central Coast.

The Delta IV Medium, as the rocket is known, uses a hydrogen first stage and a cryogenic second stage aided by solid-propellant boosters.

The Delta IV took off from Space Launch Complex 6 on south Vandenberg.

— Noozhawk executive editor Tom Bolton can be reached at tbolton@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.