A United Launch Alliance Atlas V rocket lifted off from Cape Canaveral, Fla., at 12:03 p.m. in what appeared to be a successful launch.

As of 12:15, mission control reported the rocket was flying at 13,000 mph and performing perfectly.

The Decatur-built rocket carried a reusable X-37B unmanned space plane, operated by the U.S. Air Force Rapid Capabilities Office, through a thin layer of clouds.

Another Atlas V launched the same plane in 2010, after which it orbited the Earth for 224 days.

A different X-37B, launched last year, was in orbit for 469 days before touching down in June.

Today’s flight was delayed several months as ULA investigated anomalies in a Delta IV launch in October. The launch was successful, but the upper stage did not perform as expected. The Atlas V uses a similar upper-stage engine.

The space plane, with a payload bay about the size of a pick-up truck bed, is 29 feet long and 15 feet wide. It looks like a miniature space shuttle.