At this point, the idea of a settlement on Mars is mainly limited to Hollywood movies like "Total Recall," but if Elon Musk, CEO of Space Exploration Technologies (SpaceX) has his way, a trip to Mars will be as commonplace as a trip to Europe in just several decades.

At this point, the idea of a settlement on Mars is mainly limited to Hollywood movies like "Total Recall," but if Elon Musk, CEO of Space Exploration Technologies (SpaceX) has his way, a trip to Mars will be as commonplace as a trip to Europe in just several decades.

At this point, SpaceX is focusing its efforts on commercial spaceflights to the International Space Station, the first of which will hopefully take place in December, Musk said today during an appearance at the AIAA propulsion conference. But in the coming years, Musk has high hopes for commercial journeys—and settlements—on places like the Moon and Mars.

"Ultimately, the thing that is super important in the grand scale of history is—are we on a path to becoming a multi-planet species or not? If we’re not, that’s not a very bright future. We’ll just be hanging out on Earth until some eventual calamity claims us," Musk said.

Challenges abound, of course, not the least of which is how to transport the supplies and people needed to make a new settlement workable. SpaceX thus far has a high-level idea of what is needed to make a journey to Mars possible, though "I wouldn't say it was fleshed out to a detailed level," Musk said.

First on the list would be a vehicle that's capable of delivering substantial mass to Mars and then returning to Earth. The company's planned Falcon Heavy rocket, the plans for which were , could conceivably carry 12 to 15 metric tons, but "I think you'll probably want a vehicle that can deliver something on the order of 50 metric tons ... in a fully reusable manner," Musk said.

The Falcon Heavy, which will be the world's largest rocket, will have its inaugural flight in late 2012.

When asked about using nuclear propulsion on Mars, Musk was skeptical that people would approve. "I think it's going to be tough to convince the public that we should launch large reactors into space" and possibly spread uranium on Earth, he said. It might be possible to build a reactor on Mars or the Moon, but people usually forget how heavy reactors are and that many of them usually have a source of water nearby to drive the steam turbine. If fusion were to become a reality, "that would be very cool," Musk said, but solar panels are also an option.

At this point, however, the main goal is to actually get to Mars. As soon as a base is established, there will be a bigger incentive to improve transportation, he said, pointing to ships that first traveled to the American colonies.

"Before the U.S. colonies were established, there was no forcing function for improving trips across the Atlantic. But when there was, there was a need to make those ships better and better," Musk said.

Cost, of course, is also a factor. At this point, the cost per pound for the Falcon Heavy is about $1,000, but to make this a sustainable effort, the cost per pound would probably need to be well under $100, probably closer to $50, he said. Making the Falcon Heavy totally reusable would help drive down costs.

Musk expects the effort to be a combination of private and government funding, though he said it's hard to predict what percentage would come from the government.



