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Official Space & Missile Systems Center/DoD via TwitterAfter getting its behemoth rocket off the pad at Launch Complex 39-A, SpaceX has to deploy the two dozen spacecraft into multiple orbits around Earth over several hours. To do this, it must shut down and reignite the engine of an upper-stage rocket four times, according to the…
- Official Space & Missile Systems Center/DoD via TwitterAfter getting its behemoth rocket off the pad at Launch Complex 39-A, SpaceX has to deploy the two dozen spacecraft into multiple orbits around Earth over several hours. To do this, it must shut down and reignite the engine of an upper-stage rocket four times, accordingto the company.
One satellite holds NASA’sDeep Space Atomic Clock, which may change the way robots and astronauts navigate space. Another spacecraft is the Planetary Society’sLightSail, an experiment that could change how vehicles propel themselves to a destination. The National Oceanic and Atmospheric Administration is also launching six small weather satellites built in partnership with Taiwan.
There’s even a spacecraft holdingthe ashes of 152 people, and it will orbit Earth for about 25 years before careening back as an artificial meteor.
But SpaceX will also be attempting to land all three of the rocket’s 16-story boosters back on Earth for reuse in future launches. The two attached to the side of the Falcon Heavy rocket are set to touch down on land a few minutes after liftoff.
Meanwhile, the central or core booster — which will fire longer and disconnect from the upper-stage rocket later in the flight — will try to land on a drone ship sittingabout 770 miles (1,240 kilometers)off the coast of Florida in the Atlantic Ocean.
Watch SpaceX’s launch attempt live on Tuesday morning
There’s a 20% chance that SpaceX will delay its launch because of thunderstorms, according toa forecastissued by the US Air Force on Monday morning. If the launch is pushed to its backup window 24 hours later, there’s a 30% chance of delay.
If you want to follow the launch and deployment events, we’ve included a detailed timeline below the YouTube embed.
Launch events and timing relative to the moment Falcon Heavy lifts off the pad are outlined below and come from SpaceX’spress kitfor the STP-2 mission.
-53:00— SpaceX launch director verifies go for propellant load-50:00— First-stage RP-1 (rocket grade kerosene) loading begins-45:00— First-stage LOX (liquid oxygen) loading begins-35:00— Second-stage RP-1 (rocket grade kerosene) loading begins-18:30— Second-stage LOX loading begins-07:00— Falcon Heavy begins prelaunch engine chill-01:30— Flight computer commanded to begin final prelaunch checks-01:00— Propellant tanks pressurize for flight-00:45— SpaceX launch director verifies go for launch-00:02— Engine controller commands engine-ignition sequence to start-00:00— Falcon Heavy liftoff
Once the rocket lifts off, Falcon Heavy hardware and its payload will go through a series of crucial maneuvers. The side boosters and core booster will try to separate and land. Following that, the rocket’s upper or second stage will propel into orbit, then attempt to deploy its 24 satellites from a device called the Integrated Payload Stack over several hours.
The timing and events below are also relative to liftoff, in hours, minutes, and seconds.
00:00:42— Max Q (moment of peak mechanical stress on the rocket)00:02:27— Booster engine cutoff (BECO)00:02:31— Side boosters separate from center core00:02:49— Side boosters begin boost-back burn00:03:27— Center core engine shutdown/main engine cutoff (MECO)00:03:31— Center core and 2nd stage separate00:03:38— 2nd stage engine starts (SES-1)00:04:03— Fairing deployment00:07:13— Side boosters begin entry burn00:08:41— Side booster landings00:08:38— 2nd stage engine cutoff (SECO-1)00:08:53— Center core begins entry burn00:11:21— Center core landing00:12:55— Spacecraft deployments begin01:12:39— Second-stage engine restart (SES-2)01:13:00— Second-stage engine cutoff (SECO-2)02:07:35— Second-stage engine restart (SES-3)02:08:04— Second-stage engine cutoff (SECO-3)03:27:27— Second-stage engine restart (SES-4)03:28:03— Second-stage engine cutoff (SECO-4)03:34:09— Final spacecraft deployment