
Developing SpaceX’s Falcon Heavy rocket has proven more challenging than expected, according to SpaceX founder Elon Musk.Musk said at a conference July 19 that he originally thought the project would be straightforward because Falcon Heavy is based on the existing Falcon 9. For instance, Falcon Heavy uses the same Merlin first-stage engine, though it triples the number of those engines to 27. But that initial view turned out to be “pretty naïve,” Musk conceded.“It actually ended up being way, way…