The Artemis II launch team reports to their consoles in Firing Room 1 at Kennedy Space Center.
The official countdown clock starts ticking toward the planned liftoff time.
Liquid oxygen and liquid hydrogen system preparations begin for vehicle loading. Continues through L-42H30M.
The Orion crew module is powered up and brought online for pre-flight checkout. Continues through L-44H.
The SLS core stage is powered up for system checks. Continues through L-41H.
The interim cryogenic propulsion stage is powered up for pre-launch verification. Continues through L-40H30M.
Final preparations of the four RS-25 engines begin. Continues through L-35H30M.
The ICPS is powered down following initial checkout. Continues through L-34H10M.
Orion flight batteries are charged to 100% for mission operations. Continues through L-29H30M.
Core stage flight batteries are charged ahead of propellant loading. Continues through L-24H30M.
The ICPS is powered back up in its launch configuration. Continues through L-18H45M.
All non-essential personnel depart Launch Complex 39B as hazardous operations approach. Continues through L-14H.
Air-to-gaseous nitrogen changeover begins and the rocket cavity is inerted for safety. Continues through L-12H05M.
The ground launch sequencer (GLS) is brought online to manage the automated countdown. Continues through L-11H45M.
A planned 2-hour 45-minute hold begins, providing schedule margin before tanking. Continues through L-9H50M.
The launch team decides go or no-go to begin cryogenic propellant loading.
Orion enters a cold soak phase in preparation for propellant loading operations. Continues through L-9H35M.
The core stage liquid oxygen transfer line is chilled down to cryogenic temperatures. Continues through L-10H35M.
The core stage liquid hydrogen systems are chilled in preparation for propellant fill. Continues through L-9H55M.
The core stage liquid oxygen main propulsion system is chilled to operating temperature. Continues through L-9H40M.
Liquid hydrogen slow fill begins on the core stage to gradually cool the tank. Continues through L-9H25M.
The terminal countdown clock resumes from the T-8H10M mark after the built-in hold.
Liquid oxygen slow fill begins on the core stage. Continues through L-9H30M.
Core stage liquid oxygen transitions to fast fill rate for bulk loading. Continues through L-6H40M.
Core stage liquid hydrogen transitions to fast fill rate. Continues through L-8H.
The ICPS liquid hydrogen system is chilled down to cryogenic temperatures. Continues through L-8H30M.
ICPS liquid hydrogen fast fill begins. Continues through L-7H45M.
Core stage liquid hydrogen tank transitions to topping mode. Continues through L-7H55M.
Core stage liquid hydrogen enters continuous replenish mode through terminal count.
The ICPS liquid hydrogen vent and relief valves are tested. Continues through L-7H20M.
ICPS liquid hydrogen tank transitions to topping mode. Continues through L-7H10M.
ICPS liquid hydrogen enters continuous replenish mode through terminal count.
Orion radio frequency communications to mission control are activated. Continues through L-6H10M.
Core stage liquid oxygen transitions to topping mode. Continues through L-6H05M.
ICPS liquid oxygen main propulsion system chilldown begins. Continues through L-6H30M.
ICPS liquid oxygen fast fill begins. Continues through L-5H45M.
Stage pad rescue is prepared and the closeout crew assembles for crew ingress operations.
Core stage liquid oxygen enters continuous replenish mode through terminal count.
The flight crew receives a final weather briefing for launch and abort landing sites.
ICPS liquid oxygen vent and relief valves are tested. Continues through L-5H30M.
ICPS liquid oxygen transitions to topping mode. Continues through L-5H10M.
All stages enter replenish mode. A 1-hour 10-minute built-in hold begins. Closeout crew proceeds to the white room.
The Artemis II crew departs crew quarters and travels to Launch Complex 39B. Continues through L-4H10M.
The four crew members enter the Orion spacecraft and take their seats.
The Orion crew module hatch is prepared and closed by the closeout crew. Continues through L-3H10M.
Counterbalance mechanism hatch seal and pressure decay checks verify cabin integrity. Continues through L-2H45M.
Crew module hatch service panel is installed and final closeout work is completed. Continues through L-1H40M.
The launch abort system hatch is closed and secured for flight. Continues through L-1H30M.
The launch director reviews rocket and thermal protection system scan results with the imagery console.
The closeout crew departs Launch Complex 39B. The final NASA test director briefing is held.
A planned 30-minute hold begins for final readiness assessments before terminal count.
The team transitions to the Orion-to-Earth communication loop following the final NTD briefing.
The launch director polls the entire team to confirm they are go for launch.
The Artemis II crew lowers and locks their helmet visors for launch.
A short purge of the crew suit ventilation system is verified.
The ground launch sequencer initiates the final automated terminal countdown.
The Crew Access Arm is retracted away from the Orion spacecraft.
GLS commands core stage tank pressurization. Orion ascent pyros are armed and the spacecraft switches to internal power.
Core stage liquid hydrogen replenish flow is terminated ahead of flight.
Launch abort system capability becomes available. The NTD notifies the commander.
The ground launch sequencer commands the liquid hydrogen high flow bleed check.
The flight termination system is armed for range safety.
GLS commands core stage auxiliary power unit start. Core stage LOX replenish flow is terminated.
ICPS liquid oxygen replenish flow is terminated.
The ground launch sequencer commands purge sequence 4 for engine compartment inerting.
The interim cryogenic propulsion stage transitions to internal battery power for flight.
The solid rocket boosters switch from ground power to internal battery power.
The SLS core stage transitions from ground support to internal power for flight.
The interim cryogenic propulsion stage enters its final terminal countdown mode.
ICPS liquid hydrogen replenish flow is terminated.
GLS sends the go command for the automated launch sequencer to take control.
The core stage flight computer transitions to the automated launching sequencer.
Hydrogen burn-off igniters fire beneath the RS-25 engines to clear residual hydrogen.
The ground launch sequencer sends the command for core stage engine ignition.
The four RS-25 engines ignite in a staggered sequence and ramp to full thrust.
Solid rocket boosters ignite, umbilicals separate, and Artemis II lifts off from Launch Complex 39B.
SLS clears the tower and begins the programmed roll and pitch maneuver.
The launch vehicle passes Mach 1 during ascent.
Artemis II reaches max-Q, the peak aerodynamic stress point.
A precise burn raises the apogee for the next phase of the mission profile.
Both boosters separate after completing their ascent burn.
The launch abort system is discarded once it is no longer required.
Orion departs the ICPS and begins a proximity operations demonstration.
The Orion crew completes the planned proximity operations demonstration.
Orion conducts a separation burn to widen distance from the upper stage.
The ICPS disposal sequence begins following Orion departure.
The disposal burn refines the ICPS path toward atmospheric reentry and ocean impact.
CubeSats deploy at one-minute intervals after upper stage disposal maneuvers.
The SLS core stage shuts down its RS-25 engines.
The core stage separates from the ICPS in an initial parking orbit.
The ICPS extends the RL10 nozzle in preparation for later burns.
Orion performs a perigee raise maneuver after completing early orbit operations.
Orion deploys its solar array wings for long-duration power generation.
A major burn sends Artemis II from Earth orbit onto its lunar trajectory.
Navigation teams refine the outbound translunar path.
The first listed deep-space correction burn fine-tunes Orion's trajectory.
The ICPS performs a burn to raise the parking orbit perigee.
The crew conducts an in-flight CPR operations demonstration.
Controllers verify communications performance through the DSN.
A second trajectory trim maintains the targeted lunar flyby corridor.
The first shift reviews imagery and camera procedures for the lunar flyby.
The second shift finalizes lunar flyby observation procedures.
The crew practices rapid suit donning and pressurization procedures.
The third correction burn tunes the final approach to the Moon.
Orion crosses into the region where lunar gravity dominates the trajectory.
The crew begins planned lunar observation and flyby activities.
Artemis II reaches its nearest point to the lunar surface.
The mission reaches its farthest point from Earth during the lunar flyby.
Orion departs the Moon's primary gravitational influence on the return leg.
The crew and controllers review observations from the lunar flyby.
The first return-leg correction burn refines the Earth reentry corridor.
The crew performs a shielding procedure demonstration in deep space.
The crew demonstrates manual piloting and handling procedures.
The first shift evaluates garments intended to reduce post-landing intolerance.
The second shift continues post-landing garment assessment operations.
A second return-leg correction burn sharpens the reentry path.
The final listed return correction burn completes late-mission targeting.
The crew works the atmospheric entry checklist and dons entry suits.
The Orion crew module separates from the service module before reentry.
The crew module executes a final raise burn before atmospheric interface.
Orion reaches atmospheric entry interface about 400,000 feet above Earth.
The Artemis II crew module splashes down to conclude the mission.
Post-landing safing procedures begin for the crew module thrusters.
The Orion spacecraft completes final power-down after splashdown.