After weeks of delays, NASA is counting down to April 1 for the launch of its historic Artemis II lunar flyby mission.

NASA's Artemis 2 mission will send four astronauts on a 10-day journey around the moon, the first crewed mission toward the moon in over 50 years.

Besides the Artemis II mission's primary four-person crew, NASA has picked two alternate crewmembers as backups.