SpaceX chief envisions 1000 passenger ships flying to Mars

His plans included a new 100-person SpaceX rocket that would take 26 months to reach Mars, though he estimated it would take more than 1,000 rockets to establish a city on the planet.

At the International Astronautical Congress meeting on Tuesday, the SpaceX founder revealed that humans will one day be able to travel to Mars for a meagre sum of $200,000 - if his grand plan succeeds. A self sustaining Mars city meanwhile will take anywhere between 40 to 100 years to complete.

In a tweet before the speech, which was titled "Making Humans a Multiplanetary Species", Musk said the rocket booster for his interplanetary transport system will measure about 39 feet in diameter, and the spaceship will be about 55 feet in diameter.

"One path is to stay on Earth forever, and there will be some extinction event", he said.

Musk, who also runs electric auto maker Tesla Motors, received a wildly warm reception at the International Astronautical Congress in Guadalajara, Mexico. "We do expect to generate a pretty decent net cash flow from launching satellites, servicing space station for NASA, transferring cargo to and from space station". Its Falcon rocket, though, is grounded for the second time in a year because of devastating accidents.

The rockets could ultimately be expanded to carry about 200 people. In fact, he's already begun work on the Mars Colonial fleet.

Yet he also noted that the "super-exciting" adventure to Mars would also be unsafe, at least for the first few trips.

SpaceX is working to bring that price down to the median cost of a house in the United States, which is certainly still expensive, but much more obtainable. He noted during his presentation that if the ideal colony is about 1 million people, it would require 10,000 trips by rockets carrying just 100 people.

Asked whether he would go, he said perhaps ultimately, but it would depend on whether he had a good succession plan in place.

"Basically, are you prepared to die, and if that's OK, then you're a candidate for going", he said.

SpaceX wants to send an unmanned capsule, called Red Dragon, to the surface of Mars to test descent, entry and landing systems.

While a private company, SpaceX has seen support from NASA both financially and with resources. The space agency has its own programme to get astronauts to Mars in the 2030s, using its own hardware.

The total cost for SpaceX to develop the interplanetary transport system could be $10 billion. Mars' lower gravity cancels the need for booster rockets.

The co-founder of Tesla Motors said the spaceship would be capable of carrying two or three tons per trip and would be propelled by reusable rockets that will return to Earth before taking off again to refuel the spacecraft.

The goal of course is colonisation, a motive which Musk says is necessary for the survival of humanity.

"What I really want to try to achieve here is to make Mars seem possible - like it's something we can achieve in our lifetimes", Musk told the audience.