After a 50-year absence, NASA is aiming to go back to the moon.

The space agency has dubbed its newest lunar program “Artemis,” after the twin sister of Apollo in Greek mythology, with three flights planned to the moon: an initial unmanned flight, currently scheduled to launch on Saturday; a manned flight with four astronauts in orbit around the moon, launching no earlier than 2024; and then the final flight, in which two members of the crew will land on the moon’s surface, tentatively in 2025.