Here is the latest update from Elon:
All systems have passed their prelaunch checkout and we are go for launch tomorrow at 11 a.m. California time (7 p.m. GMT).
Over the past month, we have also improved and upgraded the countdown sequence in several ways:
- More computer controlled operations vs manual
- Improved ground support equipment to load propellant/pressurant faster
- Worked with range safety to speed up checkout of the thrust termination system
- Changed to simultaneous load of LOX and fuel on both stages
The Vandenberg hold down firing countdown was 5 hours, the first Kwaj countdown was 4 hours and now we are at 3 hours. Having a responsive launch capability is important to DARPA and the Air Force (and us for cost reasons), so we've put a lot of effort into streamlining the countdown.
A C-17 buzzes Falcon for good luck