Launch of Delta IV with NROL-47 scrubbed for second day in a row

Photo Credit: ULA
United Launch Alliance scrubbed the second launch attempt of a Delta IV Medium+ (5,2) with the classified NROL-47 for the National Reconnaissance Office. However, the reason for today’s scrub differed from the prior day’s attempt.
United Launch Alliance issued the following statement regarding the scrub:
(Vandenberg Air Force Base, Calif. Jan. 11, 2018) – The launch of a United Launch Alliance Delta IV carrying the NROL-47 mission was scrubbed today due to an issue with a ground system valve.
The launch is planned for Friday, Jan. 12, from Space Launch Complex-6 at Vandenberg Air Force Base. The forecast shows a 90 percent chance of favorable weather conditions for launch. The launch time is 1:00 p.m. PT.
Jason Rhian
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.
This is going to be historic
Why? Delta IV rockets are pretty common place these days. What makes it special?
It did not fail like SpaceX Zuma- and nobody had any real worries after over 100 successes in a row. That’s why. Not blowing up or dropping a billion tax dollars in the ocean is how you make history.
All reports indicate the Falcon 9 launch vehicle performed as expected. Talk to Northrop about their payload if you want more information on what failed to deploy.
Delta IV has 36 launches under its belt, not over 100. Nice thought. Falcon 9 has 45 of 47 completed launch now. With the caveat of Zuma, which the truth may never be publicly known, making it 46/47. And the Amos explosion on the pad, 46/48.
Launch records aside, the question was “what makes this historic?”, your response was “its another routine launch”. Again I ask, what makes this historic?