NASA has begun fueling its rocket today in preparation for launching the first crewed mission to the Moon in more than half a century, with liftoff expected this evening carrying four astronauts on board.

The launch team needs to load more than 700,000 gallons of fuel into the 32-story-tall Space Launch System rocket on the launch pad, before the Artemis II crew boards the spacecraft.

Artemis II marks the first step in NASA’s broader plans to establish a permanent base on the Moon, with the goal of carrying out a landing near the lunar south pole by 2028.