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's Artemis II mission launched, marking the first crewed flight of the Orion spacecraft and Space Launch System.

Artemis II is NASA’s first crewed mission under the Artemis program and will launch from the agency’s Kennedy Space Center in Florida.