The Space Launch System rocket’s interim cryogenic propulsion stage (ICPS) and boosters were powered up overnight. Teams are in the process of clearing all non-essential personnel from the launch pad area in preparation for propellant loading operations.
At 6 a.m. EDT, or L-8 hours, 40 minutes, the launch team is expected to reach a planned 1 hour, 30-minute built-in hold. During this time the mission management team will review the status of operations, receive a weather briefing, and make a “go” or “no-go” decision to proceed with tanking operations.
Tanking milestones include filling the rocket’s core stage with several hundred thousand gallons of liquid oxygen and liquid hydrogen. This will occur over a series of different propellant loading milestones to fill, top off, and replenish the tank. Because of an issue found several days ago with a helium check valve on the rocket which cannot be fixed at the launch pad, cryogenic propellant will not be loaded into the rocket’s upper stage.
NASA is streaming live video of the rocket and spacecraft at the launch pad on the Kennedy Newsroom YouTube channel. NASA is also sharing updates on the Exploration Ground Systems Twitter account