Liftoff of a United Launch Alliance Delta IV Heavy rocket from Vandenberg Air Force Base was delayed for a third time early Tuesday afternoon, this time due to high ground winds.
ULA announced the move about five hours ahead of the planned launch. The company said it is now aiming to have the launch go off during a window set to open at 5:44 p.m. Wednesday, Dec. 19, from VAFB's Space Launch Complex-6. The forecast at that time "indicates an 80-percent chance of favorable weather conditions for launch," ULA reported.
The launch is set to be part of a mission, dubbed NROL-71, for the National Reconnaissance Office. The rocket's payload was not revealed.
The launch had initially been planned for Dec. 7 but was postponed that day "due to an issue with a redundant communication link between the control center and the launch site," according to ULA.
It was rescheduled for Dec. 8 but was postponed again that day with just 7 seconds remaining in the prelaunch countdown "due to a problem detected by the Terminal Countdown Sequencer Rack," ULA reported.