Atlas V AEHF 2

United Launch Alliance Atlas V placed the USAF's AEHF 2 satellite into orbit on May 4th, 2012 at 2:42 PM EDT.  The vehicle flew in the 531 configuration with a 5.4 meter diameter payload fairing, three solid rocket motor boosters and one RL-10 Centaur upper stage engine. AEHF (Advanced Extremely High Frequency) satellites will supplement and eventually replace the Milstar constellation currently used by US Armed Forces.