Four astronauts have embarked on a high-stakes flight around the moon, humanity’s first lunar voyage in more than half a century. It’s the thrilling leadoff in NASA’s push toward a lunar landing in two years. The 32-story moon rocket blasted off from Florida’s Kennedy Space Center Wednesday evening, carrying three Americans and one Canadian. The Artemis II crew will spend a day in orbit around Earth checking their capsule before firing the main engine that will propel them to the moon. The nearly 10-day mission will see them fly around the moon and set a distance record, before coming straight back home.