Launch day has arrived for NASA's Artemis II mission—here's what to expect

NASA’s Artemis II launch window opens at 6:24 p.m. EDT for a nine-day crewed mission to loop behind the Moon.

The Orion crew of four will travel more than a quarter-million miles and reenter at about 25,000 mph.

Launch fueling will load over 750,000 gallons of cryogenic propellant and requires careful hydrogen leak monitoring.