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.
NASA is streaming live video of the rocket and spacecraft at Launch Pad 39B and will provide live commentary on the agency’s website beginning with tanking operations on June 20. Activity at the launch pad will likely not be visible during the majority of the countdown, but some venting may be seen during propellant loading.