NASA engineers and astronauts are preparing to launch the Artemis II rocket to the moon.
The rocket will launch on Wednesday evening and loop astronauts around the moon to test critical spacecraft systems.
The mission will mark the first times human have traveled beyond low Earth orbit in decades.
Follow live coverage of the Artemis II mission, including a 24/7 live blog from pre-launch to splashdown, and major milestones on ABC News Live and streaming on Disney+ and Hulu.
Here are some key numbers involving the mission:
Number of astronauts: Four astronauts -- three Americans and a Canadian -- will be aboard.
Number of days: The entire journey, from launch to splashdown, is expected to take 10 days.
Miles traveled: Artemis II will take the astronauts on a 685,000-mile journey around the moon, known as a lunar fly-by.
Cost of the mission: The single mission is estimated to cost $4.1 billion, according to a 2021 audit from NASA’s Office of Inspector General. The entire Artemis effort was projected to cost NASA $93 billion up to fiscal year 2025, according to the audit.
Years since last lunar mission: 54. The Apollo 17 mission landed on the moon in December 1972.
Years until next Artemis mission: At least one. The Artemis III mission will launch a crew in the Orion spacecraft to test rendezvous and docking capabilities between Orion and commercial spacecraft needed to land astronauts on the moon, according to NASA. The launch is expected to take place in 2027.