NASA stacked its Orion crew capsule atop its Space Launch System (SLS) megarocket at Kennedy Space Center in Florida on Wednesday (Oct. 20), notching a major milestone for the agency and its Artemis program of crewed lunar exploration.

This Orion-SLS duo will fly the first-ever mission in that program — Artemis 1, an uncrewed flight around the moon that's targeted to launch early next year. .

In photos: The Orion space capsule: NASA's next spaceship.

Artemis 2, a crewed trip to lunar orbit, is scheduled to lift off in 2023.

Then will come Artemis 3, which will land astronauts on the moon for the first time since 1972.

—NASA to land 1st person of color on the moon with Artemis program.

Artemis activities will extend far beyond Artemis 3's landmark touchdown; NASA wants the program to establish a long-term, sustainable human presence on and around the moon by the end of the 2020s. .