UPDATE – The launch was scrubbed due to a hydrogen leak.
United Launch Alliance says the next launch window will open at 5:31 p.m. Thursday
Launch Alert: we have declared a scrub for today's launch of the #DeltaIVHeavy. We will set up for a 24 hour recycle and the next launch attempt will be 12/20 at 5:31pm PST.
— ULA (@ulalaunch) December 20, 2018
A Delta IV Heavy rocket is scheduled to launch from Vandenberg Air Force Base on Wednesday evening.
The launch window opens at 5:49 p.m.
Initially, the launch window opened at 5:44 p.m., but United Launch Alliance tweeted Wednesday that it had been pushed back a few minutes.
The launch time has been adjusted slightly to 5:49pm PST (8:49 p.m. EST; 0149 UTC) that takes into account the earlier brief hold in the countdown. #NROL71 #DeltaIVHeavy
— ULA (@ulalaunch) December 20, 2018
ULA officials have said there is an 80 percent chance of favorable weather conditions at the time of the launch.
One step closer to launch of the #NROL71 #DeltaIVHeavy. The MST is parked and processing continues as we work towards a 5:44pm PST launch tonight. Follow our live launch blog for updates at https://t.co/wLoggekye0 pic.twitter.com/qu9W55maOe
— ULA (@ulalaunch) December 19, 2018
The launch was scrubbed Tuesday evening because of high ground winds. It was delayed twice before, on December 7 and 8, due to technical issues.
The rocket will deliver a satellite for the National Reconnaissance Office into orbit.
Live on the west coast and wondering when you will see the #DeltaIVHeavy tonight? #NROL71 pic.twitter.com/poOJ6rLHxe
— ULA (@ulalaunch) December 19, 2018
