Three of the four RS-25 engines powering the Artemis II mission previously flew on NASA’s Space Shuttle fleet.

The Artemis II astronauts are officially on their way back home to Earth after their groundbreaking journey, becoming the first humans in more than 50 years to travel near Earth's celestial neighbor.

Artemis II chief training officer Jacki Mahaffey tells Tim, Maggie and Kristin how the crew were trained to expect the unexpected, how astronaut preparation has changed since the Apollo days, and how ...