As the Artemis 2 mission has been declared a go, the countdown has entered T-10 minutes and counting.
These are the key milestones to come:
T-10M – GLS initiates terminal count
T-8M – Crew Access Arm retract
T-6M – GLS go for core stage tank pressurization
T-6M – Orion ascent pyros are armed
T-6M – Orion set to internal power
T-5M57S – Core stage LH2 terminate replenish
T-5M20S – LAS capability is available
T-5M20S – NTD lets commander knows LAS capability is available
T-4M40S – GLS go for LH2 high flow bleed check
T-4M30S – Flight termination system armed
T-4M – GLS is go for core stage auxiliary power unit (APU) start
T-4M – Core Stage APU starts
T-4M – Core stage LOX terminate replenish
T-3M30S – ICPS LOX terminate replenish
T-3M10S – GLS go for purge sequence 4
T-2M02S – ICPS switches to internal battery power
T-2M – Booster switches to internal batter power
T-1M30S – Core stage switches to internal power
T-1M20S – ICPS enters terminal countdown mode
T-50S – ICPS LH2 terminate replenish
T-33S – GLS sends “go for automated launch sequencer” command
T-30S – Core stage flight computer to automated launching sequencer
T-12S – Hydrogen burn off igniters initiated
T-10S – GLS sends the command for core stage engine start
T-6.36S– RS-25 engines startup
T-0 – Booster ignition, umbilical separation, and liftoff