SpaceX called off a test flight of its Starship rocket and Super Heavy booster after the countdown clock reached zero, with engines failing to start during the launch sequence.

The ambitious mission was set to lift off from Starbase, Texas, at 5:45 pm local time on Thursday. However, the computers controlling the countdown automatically aborting the launch due to engine issues.

Engineer teams are preparing to drain the rocket's propellant tanks and replace two of the Raptor engines. Elon Musk suggested a probable next launch attempt would be early next week.

The Super Heavy booster features 33 methane-fueled Raptor engines, each capable of generating more than half a million pounds of thrust. This test flight is the second to use SpaceX’s upgraded Starship Version 3 rocket and its third-generation Raptor engine design.