As the four-person crew of Artemis II prepares to launch on a historic mission around the moon as soon as February, some experts are worried about the spacecraft’s heat shield.

A major change from the 25-day Artemis I mission in 2022 is the path the crew will take. Artemis II will use what NASA calls a "free return trajectory," which means once Orion heads toward the moon, gravity from Earth and the moon will naturally bend the spaceship's course back home, even if later engine burns fail.

Depending on the timing, NASA could launch a fresh crew to the space station while four other astronauts are flying around the moon.

America's next mission to the moon is happening in only a few weeks.

Earth’s atmosphere is slowly leaking into space, and new research shows some of it reaches the Moon, where it may be preserved in lunar soil.