NROL-71 was scrubbed last night. New liftoff scheduled for 8:06 PM today at 70% Go Launch was scrubbed once more tonight at T- 7 seconds. No news on another attempt yet.
The Delta IV Heavy is a rocket you don’t see every day. The world’s largest launch vehicle, in terms of payload size, booster size, and capability*, is quite the sight. Using three Delta IV CBC cores strapped together, it has an impressive payload capacity beating all but the Falcon Heavy Expendable, a booster that probably won’t be seen for a very long time considering SpaceX’s current stance towards losing boosters, much less three of them.
This mission, NROL-71, is one of the few remaining DIV Heavy boosters. It’s a classified launch for the NRO, one of its optical “Keyhole” spy satellites. Not much else is known, due to its classified status.
It takes off, December 8, at 8:06 PM Pacific from SLC-6. Definitely not a launch to miss!
More information per ULA can be found here: https://www.ulalaunch.com/missions/delta-iv-nrol-71
UPDATE: ULA has released their mission profile.
(Image Credit: United Launch Alliance)
* Sidenote: While the Falcon Heavy is technically the most powerful booster flying, only the RTLS version has been flown. Per NASA LSP, the RTLS version is much weaker than the Delta IV Heavy, and only the Expendable edition beats it out. Even then, past 100km/s^2 of C3, the Delta IV Heavy again pulls ahead of FH, even though it has only demonstrated this once with Parker Solar Probe.