US govt says SpaceX Falcon 9 rockets are prone to cracks

An investigation by US' Government Accountability Office has revealed that Elon Musk-led SpaceX's Falcon 9 rockets are prone to cracks. The turbo blades' tendency to crack is a "major threat to rocket safety," since they pump fuel into Falcon 9's rocket engines, the agency said. SpaceX recently won a NASA contract to launch astronauts into space.