ULA delays AEHF-6 launch due to technical difficulties ...

The United Launch Alliance (ULA) Atlas V rocket launch carrying the AEHF-6 mission for the U.S. Space Force’s Space and Missile Systems Center is delayed due to an off-nominal valve reading during launch vehicle processing. Additional time is needed for the team to replace and retest the valve. Launch is now scheduled for no earlier than March 21. 

United Launch Alliance will use an Atlas V 551 rocket to launch the sixth and final spacecraft in the Lockheed Martin-built Advanced Extremely High Frequency (AEHF) series for the U.S. Space Force Space and Missile Systems Center. AEHF satellites provide global, survivable, protected communications capabilities for strategic command and tactical warfighters operating on ground, sea and air platforms. Atlas V rockets successfully launched the first five AEHF satellites between 2010 and 2019.

The AEHF-6 launch will mark the 83rd Atlas V mission since the inaugural launch in 2002 and the 11th in the 551 configuration.