Boeing's CEO says the megarocket his company is helping to build for NASA will deliver astronauts to the Red Planet before billionaire Elon Musk's SpaceX. Space.com reports: According to Fortune, Boeing CEO Dennis Muilenburg was speaking on CNBC today when host Jim Cramer asked whether Boeing or SpaceX 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 said, according to Fortune. Boeing is the main contractor for the first stage of NASA's giant Space Launch System , which is designed to launch astronauts on deep-space missions using the space agency's new Orion spacecraft. (United Launch Alliance, Orbital ATK and Aerojet Rocketdyne are also SLS contractors.) NASA hopes to build a "Deep Space Gateway" near the moon before using SLS and Orion vehicles to send explorers to Mars. The first test launch is scheduled for 2019. "Do it," Musk tweeted.