NASA has begun a two-day practice countdown for its first moonshot with astronauts in 53 years. The dress rehearsal that started Saturday night will culminate with the fueling of the space agency's new moon rocket.

With the wet dress rehearsal, essentially a critical fueling test of the Artemis 2 Space Launch System moon rocket, now back on Feb. 2, NASA said in a statement that it can no longer target Feb. 6 or Feb. 7, the first two days of its launch window. The Artemis 2 launch window originally ran from Feb. 6 to Feb. 10.

The rollout on Saturday, Jan. 17, of the Space Launch System (SLS) rocket is a crucial step signaling that NASA is in the final stretches to get its first crewed lunar mission in five decades off the ground. That mission, known as Artemis 2, will send three Americans and one Canadian on a 10-day trip around the moon.

NASA's space shuttle Challenger completed 10 missions before it broke apart during a launch in 1986, killing seven astronauts.

SpaceX will launch an advanced, jam-resistant GPS satellite for the U.S. Space Force from Florida tonight (Jan. 26), and you can watch the action live.