In September, the Falcon 9 rocket exploded during fueling before the engine test fire. So far, the incident has been labeled "the most difficult and complex" in the company's 14-year history, Elon Musk, SpaceX's founder and chief executive, said. According to Washington Post, still images from the video became a reason for the visit. The pictures showed a strange shadow followed by a white spot on the roof of a nearby building of ULA, SpaceX's long-standing rival. The building is used for refurbishing rocket motors and has a Launchpad on its top.
Musk said, "We've eliminated all of the obvious possibilities for what occurred there. So what remains are the less probable answers."
Both companies compete over national security contracts worth hundreds of millions of dollars. Till 2014, ULA had a monopoly on them, but then faced competition from SpaceX. For now, learning about the reasons for the explosion is the company's "absolute top priority," but what caused the blast is still unknown, according to Musk.