SpaceX Mars program is a development program initiated by Elon Musk and SpaceX in order to facilitate the eventual colonization of Mars . The program includes fully reusable launch vehicles, human-rated spacecraft, on-orbit propellant tankers, rapid-turnaround launch/landing mounts , and local production of rocket fuel on Mars via in situ resource utilization (ISRU). SpaceX's aspirational goal since 2017 has been to land the first humans on Mars by 2024. A key element of the program is planned to be the SpaceX Starship, a fully reusable super-heavy lift launch vehicle under development since 2018. To achieve a large payload, the spacecraft would first enter Earth orbit, where it is expected to be refueled before it departs to Mars. After landing on Mars, the spacecraft would be loaded with locally-produced propellants to return to Earth. The expected payload for the Starship launch vehicle is to inject between 100–150 tonnes (220,000–330,000 lb) to Mars, SpaceX intends to concentrate its resources on the transportation part of the Mars colonization project, including the design of a propellant plant based on the Sabatier process that will be deployed on Mars to synthesize methane and liquid oxygen as rocket propellants from the local supply of atmospheric carbon dioxide and ground-accessible water ice. However, Musk has advocated since 2016 a larger set of long-term Mars settlement objectives, going far beyond what SpaceX projects to build; any successful colonization would ultimately involve many more economic actors —whether individuals, companies, or governments—to facilitate the growth of the human presence on Mars over many decades.