Atlas Rocket On Hold At T-Minus 4 Minutes Due To Wind

CAPE CANAVERAL, Florida  -- An Atlas V 551 rocket is on hold for launch from Space Launch Complex 41 at the Cape Canaveral Air Force Station at T-minus 4 minutes.  The forty-four minute launch window began at 5:46 p.m. E.S.T.

The Atlas payload is a U.S. Navy communications satellite dubbed MUOS, an acronym for Mobile User Objective System.  It is a next generation narrow-band tactical satellite communications system which will provide ten times more communications capability over existing systems.

According to the 45th Space Wing, weather balloons are released periodically throughout the countdown to measure the speed and direction of winds aloft. That information is computed and compared with the rocket's flight profile to ensure it is safe for the Atlas' ascent. At the current time, the situation is "red" while engineers assess the data.