Countdown To Atlas V Launch Underway At Cape Canaveral

The countdown to the planned launch tonight of an Atlas V rocket is underway at Cape Canaveral Air Force Station as United Launch Alliance aims to deploy a super-sleek mini-shuttle on a partly classified military mission.

Engineers were called to their station's about 12:42 p.m. and countdown clocks started ticking toward a planned liftoff to 7:52 p.m. The launch window tonight will extend through 8:01 p.m.

The next few hours are a fairly quiet time in the countdown. Propellant-loading operations are scheduled to begin about three hours prior to launch.

Join us for interactive Cover-It-Live coverage here in The Flame Trench beginning at 4 p.m.

In the meantime, check out this United Launch Alliance VIDEO. It shows the launch sequence through Centaur main engine cutoff 17 minutes into the mission. At that point, the flight goes into a cloak of classified secrecy and United Launch Alliance mission commentary will end.

The weather forecast is looking good. Air Force meteorologists say there is an 80 percent chance conditions will be acceptable for launch. The prime concern is the possibility of electrically charged clouds that could trigger bolts of lightning that could destroy the Atlas V in flight.

You can watch a United Launch Alliance WEBCAST beginning at 7:32 p.m.

Check out the full story on the mission HERE.

NOTE ON IMAGES: Click to enlarge the United Launch Alliance photo of the Atlas V rocket at Launch Complex 41 at Cape Canaveral Air Force Station. Photo credit: Pat Corkery/ULA. You can also click on the countdown bar chart from the United Launch Alliance mission booklet. It shows the timing of major countdown milestones leading up to the planned 7:52 p.m. launch. Click it twice for an enlarged version.