Musk's goal is to reduce the cost of human spaceflight by a factor of 10. In a 2011 interview, he said he hopes to send humans to Mars' surface within 10 to 20 years. In Ashlee Vance's biography, Musk stated that he wants to establish a Mars colony by 2040, with a population of 80,000. Musk stated that, since Mars' atmosphere lacks oxygen, all transportation would have to be electric. Musk stated in June 2016 that the first unmanned flight of the larger Mars Colonial Transporter spacecraft is aimed for departure to the red planet in 2022, to be followed by the first manned MCT Mars flight departing in 2024. In September 2016, Musk revealed details of his architecture to explore and colonize Mars. By 2016, Musk's private trust holds 54% of SpaceX stock, equivalent to 78% of voting shares.
In late 2017, SpaceX unveiled the design for its next-generation launch vehicle and spacecraft system—BFR—that would support all SpaceX launch service provider capabilities with a single set of very large vehicles: Earth-orbit, Lunar-orbit, interplanetary missions, and even intercontinental passenger transport on Earth, and totally replace the Falcon 9, Falcon Heavy and Dragon vehicles in the 2020s. The BFR will have a 9-meter core diameter. Significant development on the vehicles began in 2017, while the new rocket engine development began in 2012.Most of the info was from Wikipedia