Launch Weather Officer Mike McAleenan of the U.S. Air Force’s 45th Space Wing briefed the launch team and the forecast remains the same: a 90 percent chance of favorable conditions for liftoff this morning, with light winds out of the southwest at 8 to 10 miles per hour and a temperature of 76 degrees Fahrenheit.
Here’s a timeline of today’s countdown and ascent milestones. All times are approximate.
COUNTDOWN
Hour/Min/Sec – Events
01:13:00 – SpaceX Launch Director verifies go for propellant load
01:10:00 – RP-1 (rocket grade kerosene) loading underway
00:35:00 – LOX (liquid oxygen) loading underway
00:07:00 – Falcon 9 begins engine chill prior to launch
00:01:00 – Command flight computer to begin final prelaunch checks
00:01:00 – Propellant tank pressurization to flight pressure begins
00:00:45 – SpaceX Launch Director verifies go for launch
00:00:03 – Engine controller commands engine ignition sequence to start
00:00:00 – Falcon 9 liftoff
LAUNCH AND DRAGON DEPLOYMENT
Hour/Min/Sec – Events
00:01:19 – Max Q (moment of peak mechanical stress on the rocket)
00:02:45 – 1st stage main engine cutoff (MECO)
00:02:48 – 1st and 2nd stages separate
00:02:56 – 2nd stage engine starts
00:08:31 – 2nd stage engine cutoff (SECO)
00:09:31 – Dragon separates from 2nd stage
00:11:00 – Dragon’s solar arrays deploy
02:20:00 – Dragon’s Guidance, Navigation and Control bay door opens