United Launch Alliance has successfully launched the second advanced extremely high frequency (AEHF-2) satellite for the US military on 4 May from Kennedy Space Center (KSC) in Florida. The mission was delayed 24h due to issues with pre-launch helium injection into the Centaur upper stage adaptor.

All engine burns and throttling was reported successful. The launch marks the 30th launch for Atlas V, according to Flightglobal/Ascend's Spacetrak database, of which 29 were considered full successful.

The first AEHF launch in August, 2010, came close to disaster after an anomaly with the satellite's electric thrusters left it in a useless orbit. Operators managed to coax the satellite into a correct orbit after a series of corrective burns, which took more than one year to complete.

AEHF was launched atop an Atlas V 531, meaning the rocket had three solid rocket boosters and a single RL-10 in the Centaur upper stage. The next Atlas V launch is scheduled for 18 June from KSC, carrying a classified satellite for the National Reconnaissance Office.

Neither ULA nor the US department of defence immediately responded to questions.

Source: Flight International