SpaceX CEO Elon Musk unveils his plans to colonize Mars during the International Astronautical Congress in Guadalajara, Mexico, September 27, 2016. [Photo/Agencies]

Musk said it would be a challenge to fund the Mars effort, with development costs estimated at $10 billion. "I'm personally accumulating assets in order to fund this," he said, adding that "ultimately this is going to be a huge public-private partnership."

SpaceX, which Musk founded specifically with the purpose of colonizing Mars, is one of several private and government-funded ventures vying to put people and cargo on the Red Planet and other destinations beyond Earth's orbit.

Mars is typically 140 million miles (225 million km) from Earth and landing the first humans there, after what traditionally has been a six- to nine-month journey, is an extremely ambitious goal. Musk expects his rocket to be able to cut the transit time to as little as three months and released a four-minute video showing the craft. (http://bit.ly/2dipzuU)

Amazon.com founder Jeff Bezos's Blue Origin space venture is also designing a heavy-lift vehicle and capsule called New Armstrong, that will be capable of Mars transport, company President Rob Meyerson said.

The US government is also stepping up efforts to venture beyond the moon.

NASA is supporting SpaceX's first mission to Mars, which is targeted for launch in 2018. SpaceX wants to send an unmanned capsule, called Red Dragon, to the surface of Mars to test descent, entry and landing systems.

NASA will be providing deep-space and Mars communications relays for SpaceX and consulting services in exchange for flight data. NASA wants to be able to land payloads weighing up to about 30 tons on Mars. So far, the heaviest vehicle to land on Mars was the one-ton Curiosity rover.

For now, Musk said SpaceX's top priority is tracing the cause of its Sept. 1 accident. "It's the most vexing and difficult thing  We've eliminated all the obvious possibilities," Musk later told reporters.

He characterized the accident, SpaceX's second in 14 months, as "a small thing on a long road," adding that the company has not lost a single customer.

SpaceX has a backlog of more than 70 missions for commercial and government customers, worth more than $10 billion.

"There probably will be other failures in the future," Musk said.