SpaceX initially envisioned a 12-meter-diameter ITS concept in 2016 which was solely aimed at Mars transit and other interplanetary uses. In 2017, SpaceX articulated a smaller 9-meter-diameter BFR to replace all of SpaceX launch service provider capabilities — Earth-orbit, lunar-orbit, interplanetary missions, and potentially, even intercontinental passenger transport on Earth — but do so on a fully reusable set of vehicles with a markedly lower cost structure.[49] A large portion of the components on Starship are made of 301 stainless steel, with some being manufactured from 304L stainless steel.[50] Private passenger Yusaku Maezawa has contracted to fly around the Moon in Starship in 2023.[51][52][53]