NASA’s SpaceX CRS-29: Countdown and Ascent Milestones

Here’s a full look at the countdown and ascent milestones for tonight’s launch, targeted for 8:28 EST from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. All times are approximate:


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 engine ignition sequence start

– 00:00:00             Falcon 9 liftoff


Hr/Min/Sec     Event

-00:01:12       Max Q (moment of peak mechanical stress on the rocket)

-00:02:17       1st stage main engine cutoff (MECO)

-00:02:21       1st and 2nd stages separate

-00:02:28       2nd stage engine starts

-00:02:34       Boostback Burn Starts

-00:03:28       Boostback Burn Ends

-00:06:10       1st stage entry burn starts

-00:06:22       1st stage entry burn ends

-00:07:19       1st stage landing burn starts

-00:07:36       1st stage landing

-00:08:33       2nd stage engine cutoff (SECO-1)