CAPE CANAVERAL, Fla. (AP) — Fuel leaks and a possible crack discovered during final liftoff preparations are threatening to delay the launch of NASA’s mighty new moon rocket Monday on its shakedown flight with three test dummies aboard. As precious minutes ticked away, NASA repeatedly stopped and started the fueling of the Space Launch System rocket with nearly 1 million gallons of super-cold hydrogen and oxygen because of a leak. Later in the morning, a possible crack or some other defect was spotted. The rocket is set to lift off on a mission to put a crew capsule into orbit around the moon. The launch represents a major milestone in America’s quest to put astronauts back on the moon for the first time since the Apollo program ended 50 years ago.