American space company SpaceX has successfully launched its large Falcon Heavy rocket on a flight to deploy 24 satellites. The rocket lifted off early Tuesday morning from Florida’s Kennedy Space Center. The Falcon Heavy is considered the world’s most powerful operating rocket. It was the third successful flight of a Falcon Heavy rocket. The U.S. Department of Defense ordered the current mission. The satellites will be used for experiments involving several U.S. government agencies, as well as some university projects. SpaceX chief Elon Musk said Tuesday’s mission was the company’s “toughest rocket launch ever.” It required four separate upper-stage engine firings. The satellites also needed to be placed in three different orbits. The process was expected to take about six hours. SpaceX uses reusable rockets to reduce the cost of space travel for its customers.