Key Milestones for Today’s Launch

CRS-23 mission Falcon 9 rocket and Dragon spacecraft
An instantaneous window for today’s CRS-23 launch from NASA’s Kennedy Space Center in Florida opens at approximately 3:14 a.m. EDT. Credit: NASA

Packed with more than 4,800 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 3:14 a.m.

Here is a look at some key milestones:

Mission Timeline (all times approximate)
COUNTDOWN
Hour/Min/Sec      Events
– 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 AND DRAGON DEPLOYMENT
Hour/Min/Sec      Events
– 00:01:12               Max Q (moment of peak mechanical stress on the rocket)
– 00:02:27               1st stage main engine cutoff (MECO)
– 00:02:30               1st and 2nd stages separate
– 00:02:38               2nd stage engine starts
– 00:05:49               1st stage entry burn begins
– 00:07:38               1st stage landing
– 00:08:34               2nd stage engine cutoff (SECO)
– 00:11:45               Dragon separates from 2nd stage

Follow launch activities at the mission blog and @NASAKennedy and learn more about space station activities by following @space_station and @ISS_Research on Twitter as well as the ISS Facebook and ISS Instagram accounts.