Packed with more than 6,500 pounds of research, crew supplies and hardware, the SpaceX Dragon spacecraft will launch on a Falcon 9 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida today at 5:07 a.m EST.
Here’s a look at some of today’s countdown and ascent milestones. All times are approximate:
COUNTDOWN
Hr/Min/Sec Event
– 00:38:00 SpaceX Launch Director verifies go for propellant load
– 00:35:00 RP-1 (rocket grade kerosene) loading begins
– 00:35:00 1st stage LOX (liquid oxygen) loading begins
– 00:16:00 2nd stage LOX loading begins
– 00:07:00 Falcon 9 begins pre-launch engine chill
– 00:05:00 Dragon transitions to internal power
– 00:01:00 Command flight computer to begin final prelaunch checks
– 00:01:00 Propellant tanks pressurize for flight
– 00:00:45 SpaceX Launch Director verifies go for launch
– 00:00:03 Engine controller commands ignition sequence to start
– 00:00:00 Falcon 9 liftoff
LAUNCH, LANDING, AND DRAGON DEPLOYMENT
Hr/Min/Sec Event
00:01:18 Max Q (moment of peak mechanical stress on the rocket)
00:02:30 1st stage main engine cutoff (MECO)
00:02:34 1st and 2nd stages separate
00:02:41 2nd stage engine starts
00:06:37 1st stage entry burn begins
00:08:38 2nd stage engine cutoff (SECO)
00:08:38 1st stage landing
00:11:49 Dragon separates from 2nd stage
00:12:35 Dragon nosecone open sequence begins
Follow launch activities on the mission blog, view more live coverage and countdown commentary beginning on NASA Television and the agency’s website, as well as YouTube, Twitter, Facebook, LinkedIn, Twitch, Daily Motion, Theta.TV and NASA’s App.