At approximately 5 p.m. EDT today, the launch team arrived at their stations inside the Launch Control Center at NASA’s Kennedy Space Center in Florida to begin the wet dress rehearsal test for NASA’s Artemis I mission. The countdown began 30 minutes later at 5:30 p.m. or L-45 hours, 10 minutes before the initial target T-0 of 2:40 p.m. on Monday, June 20.
Overnight, teams will power up the Orion spacecraft and the Space Launch System core stage and prepare the rocket’s four RS-25 engines, which will not be lit during the test.
Weather constraints for propellant loading operations planned for Monday stipulate there must be less than a 20% chance lightning within 5 nautical miles of pad during the first hour of tanking. Winds also must not be above 37.5 knots and the temperature cannot be below 41 degrees Fahrenheit