Live at The Cape: Atlas Aims To Launch Tuesday

A powerful Atlas V rocket is perched on a seaside launch pad at Cape Canaveral Air Force Station as engineers prepare to pick up the countdown to a planned launch Tuesday night.

The 192-foot United Launch Alliance rocket is scheduled to blast off from Launch Complex 41 at 9:24 p.m. EDT Tuesday. The launch window will extend until 10:01 p.m.

You can watch the launch live here in The Flame Trench. We'll webcast live United Launch Alliance coverage beginning about 25 minutes prior to launch and we'll have countdown updates in the blog throughout the day.

Forecasters at the Air Force 45th Space Wing Weather Squadron will be keeping close tabs on a cold front that is expected to sweep into northern Florida and then migrate into east central Florida on Tuesday. They say there is a 40 percent chance thick, electrically charged clouds or gusty ground winds could keep the Atlas V on the ground. In that case, the launch window on Wednesday would extend from 9:24 p.m. to 10 p.m.

You can check out all the details in the weather squadron's Official Launch Forecast.

The Atlas V 421 vehicle comprises a common core stage powered by a sporty Russian RD-180 rocket engine, two Aerojet solid rocket boosters, a Centaur upper stage powered by a single Pratt & Whitney RL10 engine and a four-meter-diameter payload fairing.

Nestled in the nosecone is a Wideband Global SATCOM spacecraft that is the second in a series of new-generation military communications satellites that will serve U.S. troops soldiering in theaters around the world.

The WGS satellites are replacing Defense Satellite Communications System spacecraft and are expected to operate for 10 to 15 years in orbit.

The Air Force paid $790 million for three of the Boeing-built spacecraft. The first of those was launched aboard an Atlas V 421 rocket in October of 2007. The third is tentatively scheduled for launch aboard a Delta IV at LC-41 in July or August.

The cost of launch services for the mission is $120 million, Air Force officials said in a recent media teleconference.

The Atlas V rocket began its slow move out of the 300-foot-tall Vertical Integration Facility at Launch Complex 41 shortly after 10 a.m. and made the one-third-of-a-mile trip out to the launch pad in about a half hour.

The mission is one of six Atlas V launches planned during the year. Five of those will be flown from Cape Canaveral. Next up for Atlas at the Cape: the May 20 launch of NASA's Lunar Reconnaissance Orbiter.

ABOUT THE IMAGES: Click to enlarge the United Launch Alliance images of the Atlas V rocket being transported to the pad at Launch Complex 41 from the 300-foot-tall Vehicle Integration Facility. You can also click on the enlarged image to get an even bigger view. Photo credit: Pat Corkery/United Launch Alliance.