Atlas 5 launches military payload from Vandenberg

Atlas V rocket lifts-off from California on a military flight. (ULA)

An unmanned rocket successfully launched on a classified military payload delivery flight this evening from the California coastline.

It was the twenty-fifth flight of an Atlas V rocket since the rocket series began in 2002.

In an unusual styled launch, the Air Force used a single solid rocket booster to aide the core engine's thrust at lift-off.

Lt. Col. Jenns Robertson with the 4th Space Launch Squadron operations said on Tuesday, "This Atlas rocket launch is unique in that it has just one booster attached to the side of the rocket."

The asymmetrical look of the vehicle with just one booster was drawn up over a decade ago to assist specific weight payloads at launch.

Lt. Col. Robertson added, "We didn't need two solids, with the powerful RD-180 engines on board, so we use just the one."

Lift-off of the United Launch Alliance Atlas V 411 occurred on time at 9:24 p.m. PDT (12:24 a.m. EDT today) from pad SLC-3East at Vandenberg, AFB in California. It was the fifth Atlas V launch overall from the West Coast.

"The wind cooperated with us this evening enabling us to launch without compromising public safety," 30th Space Wing commander Col. Richard Boltz stated minutes after lift-off. "Without a doubt, every launch is a major feat, and I'm extremely proud of Team Vandenberg for yet another job well done."

Winds were of concern earlier in the day, but it never delayed the Atlas from departing on time.

As the rocket soared into the dark night sky, it's Russian built RD-180 engine burned for just over four minutes providing over 930,000 pounds of thrust.

Meanwhile, the Atlas' lone booster burned in sync for just over ninety seconds giving the rocket an additional 285,000 pounds of thrust.

Following the booster's departure, the first stage engine shutdown on time and seconds later the first stage separated.

The Centaur stage then ignited pushing it's payload higher as it soared southerly out over the Pacific Ocean.

The classified payload is known as the NROL-34, a military satellite which will join the fleet of larger NROL satellites.

Specifics of the payload is unknown, but once operational in weeks, it will help support U.S. operations around the world, including early warning detection of enemy aircraft.

Tonight's launch marked the 605th Atlas launch since the first Atlas rocket's flight in 1957.

The next launch from this historic launch complex is a Delta II in June.