The SpaceX CEO stated via Twitter that he’s “confident” moving to Mars will one day cost $500,000 for a return ticket, possibly dropping further to below $100,000. These figures, Musk explained, are “very dependent on volume.” It comes as SpaceX is working to complete the Starship, a fully reusable stainless steel vehicle designed to comfortably transport around 100 humans to Mars and even beyond . The Starship uses liquid oxygen and methane to power its Raptor engines , meaning humans can set up a propellant plant on Mars to create more fuel and return to Earth. Musk claimed on Monday that “there’s a path” to building the Starship for less than the Falcon 9 SpaceX currently uses to send satellites into space, estimated to cost $62 million.