A launch countdown includes “L Minus” to indicate how far away liftoff is in hours and minutes, and “T Minus” to show a sequence of events built into the launch countdown.

NASA completed the engine burn on April 2 that will send the four astronauts of Artemis II on their way around the moon — and deeper into space than any crew in more than 50 years.

Since launch, the vehicle has separated from its launch system and been manually piloted, testing how the Orion capsule will dock with future lunar landers.