Four astronauts have embarked on a high-stakes flight around the moon, humanity’s first lunar voyage in more than half a century.

Four astronauts embarked on a high-stakes flight around the moon Wednesday, humanity’s first lunar voyage in more than half a century and the thrilling leadoff in NASA’s push toward a landing in two years.

Carrying three Americans and one Canadian, the 32-story rocket rose from NASA’s Kennedy Space Center where tens of thousands gathered to witness the dawn of this new era. Crowds also jammed the surrounding roads and beaches, reminiscent of the Apollo moonshots in the 1960s and ’70s. It is NASA’s biggest step yet toward establishing a permanent lunar presence.