SpaceX launched its Falcon Heavy rocket on Tuesday from Kennedy Space Center in Florida.(File)

SpaceX launched its Falcon Heavy rocket on Tuesday from Kennedy Space Center in Florida, carrying 24 experimental satellites in what Elon Musk's rocket company called one of the most difficult launches it has attempted.The craft blasted off to cheers from onlookers at 2:30 am.

After a three-hour delay from the original launch time late Monday. The boosters separated safely and the craft began its six-hour mission to deploy the satellites.The mission, dubbed Space Test Program 2 (STP-2), is the third one for the Falcon heavy rocket, described as the most powerful launch system in the world.

It was commissioned by the US.

Department of Defense, the key contractor for commercial space companies such as SpaceX. The company is putting satellites into orbit for various agencies, including NASA, the National Oceanic and Atmospheric Administration (NOAA), various defense department laboratories, universities and a non-profit, SpaceX said