NASA has delayed the launch of its Artemis 1 moon mission which was supposed to take off on Monday.

The decision by NASA came after an official announced that the agency was worried about possible fuel leaks and a crack found during final preparations for liftoff.

NASA will reportedly not attempt another launch until at least Friday but it is likely the delay will be longer.

"The fear now is that the problem is in engine 3. If so, it can't be swapped out on the pad but will have to go back to the [vehicle assembly building]," former NASA engineer Homer Hickham told Fox News. “The delay will be not days but weeks. We shall see. There's tons of data for the engineers to study before they can come to any conclusion about today's attempt and whether the [Space Launch System] rocket can stay on the pad and try for Friday."

The fuel leak, which saw NASA unable to fully fuel the rocket with super-cooled hydrogen and oxygen, led to the cancelling of the moon mission's much anticipated scheduled takeoff. The leak was discovered in the same area that had issues with leakage during a spring run-through of the launch.

NASA officials said that a second leak in a valve was also found.

Further complicating the launch, a crack was discovered on the rocket’s core stage, the fuel tank with four main engines. It was spotted after frost appeared on the area, according to NASA officials.

The six-week mission’s goal is to place a crew capsule with three simulated astronauts into moon orbit. The flight is in preparation for NASA’s eventual return to the moon.

The 322-foot rocket is the largest of its kind built by NASA.