SpaceX chief Elon Musk offered a detailed description Tuesday of his company's plans to begin private missions to eventually transport colonists to live on Mars.
He described a goal of lowering the estimated cost of transporting an earthling to the red planet from 10 billion dollars using existing techniques to 200,000 dollars, roughly the median cost of a home in the United States.
"You can't create a self-sustaining civilization on Mars if the ticket price is 10 billion dollars per person," he said in a live streamed address to the annual International Astronautical Congress in Guadalajara, Mexico.
SpaceX is one of two private firms contracted by US space agency NASA to deliver cargo to the orbiting International Space Station (ISS), using the company's Dragon capsule atop reusable Falcon 9 rockets.
Musk, an engineer and investor who made billions as a co-founder of online payment system PayPal, founded SpaceX.
SpaceX has struggled to successfully land its Falcon 9 rockets on an unmanned floating platform on rolling seas. It has successfully landed a reusable rocket on solid ground twice. A Falcon 9 exploded on September 1 on a launch pad at Cape Canaveral, Florida.
Musk argued that humanity's long-term survival requires "becoming a multi-planetary species," starting within Earth's solar system and someday beyond.
"Eventually, history suggests there will be some doomsday event," he warned.
Mars is the best target for human colonization, Musk said, and a self-sustainable city of 1 million people could be built within 40 to 100 years.
"How do we figure out how to take you to Mars and become a self-sustaining city?" he asked. "That's what we want."
He outlined a general strategy that includes using fully reusable spacecraft that eventually can carry at least 100 people, and producing fuel for transports using carbon dioxide and water available on Mars.
Musk said that he was continuing to amass his own fortune through investments with the main goal of helping "to make the biggest contribution I can to making life multi-planetary."