At a presentation today, SpaceX founder Elon Musk basically said that his life's mission is to make humans an interplanetary species. "The main reason I'm personally accumulating assets is in order to fund this," he said at the 67th annual International Astronautical Conference in Guadalajara, Mexico. "So I really don't have any other motivation for personally accumulating assets except to be able to make the biggest contribution I can to making life multi-planetary." In addition to reinforcing his passion and commitment to Mars travel (which shouldn't come as a surprise to anyone who follows space news), Musk also laid out his plan to get humanity to the Red Planet in great detail.
Here are some highlights and quotes from the hour-plus presentation.
Orbital refueling for the Mars Colonial Fleet
Unlike other space-going vessels, the SpaceX ship that will make the journey to Mars will first be launched into a stable orbit around Earth. The booster rocket that puts it there will then return to the launch site to pick up a fuel tank, which will deliver fuel to the craft in orbit and likewise return to Earth. The ship itself will then blast off to Mars.
The actual launch process is dramatically detailed in this video, which was released today to coincide with Musk's presentation.
While the video shows just one capsule leaving for Mars, Musk today said that it's more likely that an armada of ships would head off to the Red Planet. "Over time there will many spaceships," he said. "You'd ultimately have upwards of, I think, a thousand or more spaceships waiting in orbit. And so the Mars Colonial Fleet would depart en masse, kind of like 'Battlestar Galactica.'"
Move to Mars for less than US$100,000
As you might expect from the former CEO of PayPal, Musk said that one of the key components of SpaceX's plan is bringing the cost down, which we've heard from him before. Flights to the Red Planet need to be made attractive and relatively affordable in order to make the project viable, he said. To do this, Musk laid out a four-part plan that includes the aforementioned refueling in space, along with full reusability, choosing the right propellant, and manufacturing that propellant on Mars.
As we saw repeatedly this year, SpaceX has made great progress in the reusability arena regarding the safe return of its Falcon 9 booster rockets. Musk said that kind of thinking will continue in the Mars program, with the booster able to make an estimated 1,000 launches and returns over the course of its lifespan. He also indicated that the tanker that will refuel the ships would be able to operate for about 100 times.
Musk showed this slide to emphasize how important it is to have reusable craft in the space program. If Boeing could only use their 737 one time, the price per ticket would be US$500,000.
As for the propellant, Musk said that SpaceX has decided to go with methane, a decision that was actually announced several years ago. The fuel choice again contributes to lower costs and also helps with the fourth pillar of affordability – the ability to manufacture it once on Mars. Using the planet's CO2 and water ice stores, SpaceX believes a methane-manufacturing plant could be set up there that uses the Sabatier reaction, which converts those two compounds into methane gas and water using high pressure, high temperature and a nickel catalyst.
Thanks to all of these cost-reduction methods, Musk said that the average price of moving to Mars – including luggage and life support – could come in below US$100,000.
As for the booster itself, which Musk said is a scaled-up Falcon 9, SpaceX decided to start by designing the most difficult components first – the Raptor engines that will power it.
"This is going to be the highest chamber-pressure engine of any kind and probably the highest thrust-to-weight," he said. "It's a full-flow stage-combustion engine which maximizes the theoretical momentum you can get out of a given source of fuel.
"We sub-cool the oxygen or methane to densify it," he continued. "Propellants are used close to their boiling points in most rockets, in our case we actually load the propellants close to their freezing points and that can result in a density improvement of up to 10-12 percent, which makes an enormous difference in the actual results of the rocket."
The booster, which will accelerate the spacecraft to 8,500 km/h (5,282 mph), will contain 42 of the company's raptor engines, seven of which will be gimbaled in the center for steering purposes. The high number of engines, Musk said, will be in part for redundancy so that if any of them fail to function, the mission could still continue safely.
Musk showed footage of the rocket being fired at the presentation and thanked his SpaceX staff for getting it operational before the conference.
A million Martians
As for the size of an eventual Mars city, Musk indicated that a million inhabitants felt about right. To get there, he said that the spaceships, which will hold 100 people each, would obviously need to make thousands of flights. Because the ships could only be sent about once every two years when Earth and Mars are at their closest, Musk estimated that it would take between 40 to 100 years for the fully self-sustaining settlement to be established. He also noted that he expects the size of the spacecraft to eventually be able to hold up to 200 people.
Fun and games
Musk said that depending on the particular Earth/Mars rendezvous that passengers wanted to catch, the trip time while traveling at six kilometers (3.7 miles) per second would be about 88 days. "Ultimately I'd suspect you'd see Mars transit times in as little as 30 days in the more distant future. So it's fairly manageable considering the trips that people used to do in the old days, such as sailing voyages that would take six months or more."
So what will people do during that time?
"In order to make it appealing … it's got to be really fun and exciting," Musk said. "And it can't feel cramped or boring. So the occupant compartment is such that you can do zero-g games, you can float around, there'll be movies, lecture halls and a restaurant. It'll be like, really fun to go. You'll have a great time."
A look inside the fuel tank. While the interior surface looks faceted, Musk said it's actually completely smooth. The effect is created by the carbon fiber from which the tank is made.
2002, A space odyssey
When speaking about the history of SpaceX and how far it's come, Musk said that in 2002 he thought the company really only had about a ten percent chance of accomplishing its goals. But that didn't dampen his drive.
"I came to the conclusion that if there wasn't some new entrant into the space arena, with a strong ideological motivation, then it didn't seem like we were on a trajectory to ever be a space-based civilization and to be out there amongst the stars," he said. "In '69 we were able to go to the moon, and then the space shuttle could get to low-Earth orbit, and then space shuttle got retired, so the trend line is down to zero.
"I think what a lot of people don't appreciate is that technology doesn't automatically improve. It only improves if a lot of really strong engineering talent is applied to the problem. And there are many examples in history where people have reached a certain technology level and have fallen well below that and then recovered only millennia later."
For more of Musk's thoughts on SpaceX's Mars program and a look at many of the slides shown during the presentation, scroll through the images in the photo gallery.
The full presentation can be viewed below.