How Does SpaceX Plan To Move Thousands Of Humans To Mars?

Founder Elon Musk said he wants to send 80,000 people to Mars--per year.

SpaceX founder/Tony Stark movie inspiration Elon Musk made some heads turn this week, as heads are wont to do when they hear someone plans to ship 80,000 people to Mars. In a talk at the Royal Aeronautical Society, Musk offered early ideas on how to start a colony on the Red Planet. Then, yesterday, he doubled down with a tweet.

Millions of people needed for Mars colony, so 80k+ would just be the number moving to Mars per year news.yahoo.com/huge-mars-colo… -- Elon Musk (@elonmusk) November 27, 2012

So, to recap: Musk wants his private spaceflight business to send 80,000 people to Mars every year. They're not going to do that themselves, probably, but the company would certainly be leading the charge.

How are they going to do that?

Well, as Talking Points Memo writes, one of SpaceX's big pushes is for reusable rockets. We've had something like that in the form of NASA's classic space shuttles, but the refurbishing, Musk has said, is too much to truly make repeat space-travel cost-effective. In the RAS talk, he says that technology is still some time away--maybe five to six years before we can fully reuse a craft.

Whatever that reusable craft for colonists is, it's not going to be a current SpaceX model, like the Falcon 9 rocket. They're going to need a bigger boat: shipping off a considerable amount of people and cargo isn't feasible with the spacecrafts we have now. (Even with SpaceX's 22-story Falcon Heavy rocket, capable of carrying 117,000 pounds.) The new spacecraft, whatever it looks like, would probably run on methane, which Musk determined was the cheapest option.

But Musk, in the talk, adds a caveat to all of this: that five or six years for a reusable rocket has a "hopefully" tagged on to it. Some of these plans rely on improvements in technology, and he admits those improvements aren't simple to predict. It helps to remember, too, that this is still a sketchy idea: we need to have an infrastructure on Mars for those colonists, and it's not clear how long the gap is between "having the technology" to "sending people to Mars with the technology." Musk said last year that we were between 10 and 20 years away (worst-case scenario) from putting people on Mars, and that SpaceX would just handle transport, not the actual colonies.