"...According to the information available to us, the decision was taken late Friday 18 December following a US Air Force review of the readiness of the Air Force's satellite ground control system to support the ARGOS launch and subsequent operations. Earlier this year, the Air Force selected a new contractor to manage its ground operations system based at Kirtland Air Force Base in New Mexico. In September the Air Force decided to delay the ARGOS/Ørsted/SUNSAT launch from 17 December to 8 January to provide additional time for the new contractor to prepare and test the ground control system before the ARGOS launch. Apparently, during a review late last week, Air Force officials at Kirtland concluded that the ground system -- which will control and support ARGOS in orbit -- needed further testing and verification before a green light could be given for the launch...."
"..Assuming the above understanding is correct, we cannot place high confidence on the Air Force being ready on the 14th. NASA will discuss the situation further with the Air Force on Monday 21 December and may, following this discussion, be able to provide a more confident assessment..."
"...The final decision regarding a launch on the 14th will for practical reasons have to be taken on 4 January when the final spacecraft close out is scheduled to take place...."