The countdown continues toward liftoff at 4:30 p.m. EDT. Starting at about seven minutes before launch, the Falcon 9’s engines will be chilled to condition them for the super-cold oxidizer — liquid oxygen.
About three minutes prior to liftoff, the umbilical tower-like strongback support structure will be lowered away from the rocket.
At 90 seconds, the SpaceX launch director will verify “go for launch.”
With about 60 seconds remaining, the flight computer will run its prelaunch checks and the rocket’s propellant tanks will be pressurized.
The terminal stage of the countdown begins at T-minus 30 seconds.
Photo credit: NASA/Kim Shiflett