The launch of a Delta IV Heavy rocket from Vandenberg Air Force Base was called off in the final seconds Saturday night, marking the second delay in two days for the planned liftoff.
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 been planned for 8:06 p.m. Saturday but was pushed back to 8:15 with about a half hour remaining before that targeted time. With just 7 seconds remaining in the final countdown, however, the launch sequence was halted "due to a problem detected by the Terminal Countdown Sequencer Rack," according to United Launch Alliance, which provided the rocket.
It was called off completely, at least for Saturday night, less than 15 minutes later.
No makeup date was immediately revealed.
The launch had initially been scheduled for Friday night, but was called off Friday evening "due to an issue with a redundant communication link between the control center and the launch site," according to ULA.