Watch live as NASA conducts crucial countdown test for its new Moon rocket

NASA is going to fuel its new Moon rocket, the Space Launch System (SLS) at launch pad 39B at the Kennedy Space Center for a practice countdown ahead of its planned inaugural launch this summer. This test, known as a wet dress rehearsal, started Friday and is supposed to culminate with a countdown cutoff at T-9 seconds. Due to a helium valve issue only the core stage of the rocket will be loaded with super cold propellants today. Follow the countdown with our live views of the mammoth rocket on launch pad 39B and commentary from Spaceflight Now’s editor, Stephen Clark. The Space Launch System rocket will launch NASA’s Orion capsule on a loop around the Moon on the Artemis 1 mission. Launch is currently targeted for June but that depends on the outcome of this countdown rehearsal. If you would like to support our coverage please consider becoming a Spaceflight Now Member: