Making Synapses · Bringing Knowledge to Mankind
SpaceT-0: liftoff and ascent
The count reaches zero. The boosters ignite, the umbilicals let go and the rocket leaves the pad. You call each ascent milestone the way NASA called them for Artemis II, from the tower clear to booster separation, main engine cutoff and the solar arrays opening about 18 minutes after launch.
Free to startScenarios
- Artemis II: liftoff at 6:35 p.m. EDT from Launch Complex 39B at NASA's Kennedy Space Center.
- Each ascent milestone comes a few seconds early or late against its planned time.
The steps
- T-0: the twin solid rocket boosters ignite and deliver more than 75 % of the thrust needed to lift the 5.75-million-pound rocket.
- With the four RS-25 engines already at full thrust, the rocket makes 8.8 million pounds of force at liftoff.
- The umbilicals for power, fuel and data disconnect and retract into protective housings: the vehicle is free of the ground systems.
- 7 seconds: the rocket clears the launch tower and starts its roll and pitch maneuver.
- 56 seconds: supersonic speed. 1 minute 12 seconds: maximum dynamic pressure.
- 2 minutes 9 seconds: solid rocket booster separation; then the spacecraft adapter fairings separate and, at 3 minutes 13 seconds, the launch abort system is jettisoned.
- 8 minutes 2 seconds: core stage main engine cutoff; 8 minutes 14 seconds: the core stage separates from the upper stage.
- About 18 minutes after launch: the solar array wings deploy and lock, and Orion starts drawing power.
To pass
- Each milestone called in order, within several seconds of its planned time.
- Boosters, fairings, launch abort system and core stage separated in their order.
- Solar array wings deployed and drawing power.
Official source
NASA · Artemis II launch day
Artemis II Launch Day Updates
NASA publishes its Artemis II launch day updates free: liftoff, the thrust figures and every ascent milestone with its mission elapsed time.
Making Synapses is not affiliated with, sponsored by or endorsed by NASA, the FAA, the Canadian Space Agency or any launch provider. Agency, mission and program names are named only to describe the content.