On CNBC Thursday morning, host Jim Cramer asked Muilenburg whether he or Musk would “get a man on Mars first.” “Eventually we’re going to go to Mars and I firmly believe the first person that sets foot on Mars will get there on a Boeing rocket,” Muilenburg responded. Elon Musk offered a pithy response on Twitter: "Do it." This is not the first time Muilenburg has challenged Musk’s plans to initiate human travel to Mars. At a tech conference last year in Chicago, Muilenburg echoed a nearly identical sentiment. “I’m convinced that the first person to step foot on Mars will arrive there riding on a Boeing rocket,” he said, according to Bloomberg. In recent years, Musk has generally been recognized as the face of mankind’s goal to colonize Mars due to his celebrity status.