SpaceX plans to use a Falcon 9 rocket to test some of BFR's key features even before the company builds a full-sized version of its interplanetary vehicle. The private space corporation's chief, Elon Musk, has revealed on Twitter (like he usually does) that SpaceX plans to upgrade the second stage of a Falcon 9 "to be like a mini-BFR ship." See, the BFR (or Big Falcon Rocket) comes with a passenger spacecraft that can carry up to 100 people and up to 450 tons of cargo. The company specifically designed it for manned and big cargo missions to the moon, Mars and farther locations. SpaceX is even hoping to use the BFR to establish a Martian base and colony in the future.