Founder of SpaceX and Tesla also sees intercontinental passenger rocket development
Musk aims for Mars cargo trips by 2022
Silicon Valley billionaire Elon Musk has outlined ambitious plans for a manned mission to Mars and a rocket capable of carrying passengers from one continent to another on Earth.
SpaceX plans its first trip to the red planet in 2022, carrying only cargo, to be followed by a manned mission in 2024, Mr Musk, who runs the company and the electric luxury car company Tesla, said in Adelaide.
Nasa's first human mission to Mars is expected about a decade later.
Mr Musk, the chief executive and lead designer of Space Exploration Technologies, said SpaceX has shrunk the size of the rocket ship it is developing to go to Mars, aiming to start construction on the first spaceship in the first half of next year.
As for the intercontinental passenger rocket - a concept familiar to science fiction fans - Mr Musk said: "If you build a ship that's capable of going to Mars, what if you take that same ship and go from one place to another on Earth? We looked at that and the results are quite interesting."
Mr Musk had previously planned to use a suite of space vehicles to support the colonisation of Mars, beginning with an unmanned capsule called Red Dragon in 2018, but he said SpaceX is now focused on a single, slimmer and shorter rocket instead.
The rocket would be partially reusable and capable of flight directly from Earth to Mars, could still carry 100 passengers, and could also be used for fast transport on Earth, Mr Musk said.
SpaceX is one of several ventures that have said they want to open up space routes to Mars.
Lockheed Martin announced separate plans for a manned Mars journey at the weekend, unveiling concept drawings of a "base camp" space station orbiting Mars and landing craft that would carry four astronauts to the planet's surface.
"We know its cold, it's pretty inhospitable, so we start with the robots and then we go down with these landers," said Rob Chambers, Lockheed's director of human space flight strategy.
Mr Chambers gave no date, but the planned mission would be a joint expedition with Nasa, which aims to reach Mars during the 2030s.
Mars is typically 225 million kilometres from Earth, and landing the first humans there, after what traditionally has been seen as a six to nine-month journey, is an extremely ambitious goal.
SpaceX, which Mr Musk founded with the aim of colonising 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.
Amazon.com founder Jeff Bezos' Blue Origin space venture is also designing a heavy-lift vehicle called New Armstrong that will be capable of Mars transport.
Russia and China are each preparing for manned missions to the moon, and Russia has agreed to work with Nasa planning a "deep space gateway" space station in lunar orbit, which would serve as a staging post for future missions.