Illustration of a passenger-carrying SpaceX Starship spacecraft (upper right) being refilled with propellant from a tanker version of the Starship (lower left) while in space. Being able to refuel after launch substantially increases the payload weight that Starship is able to carry. This spacecraft is designed to be able to carry cargo and passengers to Earth orbit, the Moon, Mars and beyond as part of a two stage reusable launch system. The Starship is 50 metres long and nine metres in diameter with six methane/oxygen-propellant Raptor engines. It is constructed from stainless steel. Low altitude testing of Starship prototypes began in 2019. Its first private lunar passenger flight is scheduled for 2023.