In perhaps the most eagerly anticipated aerospace announcement of the year, SpaceX founder Elon Musk has revealed his grand plan for establishing a human settlement on Mars.

In short, Musk thinks it’s possible to begin shuttling thousands of people between Earth and our smaller, redder neighbor sometime within the next decade or so. And not too long after that—perhaps 40 or a hundred years later, Mars could be home to a self-sustaining colony of a million people.

“This is not about everyone moving to Mars, this is about becoming multiplanetary,” he said on September 27 at the International Astronautical Congress in Guadalajara, Mexico. “This is really about minimizing existential risk and having a tremendous sense of adventure.”

Musk’s timeline sounds ambitious, and that's something he readily acknowledges.

“I think the technical outline of the plan is about right. He also didn’t pretend that it was going to be easy and that they were going to do it in ten years,” says Bobby Braun, NASA’s former chief technologist who’s now at Georgia Tech University. “I mean, who’s to say what’s possible in a hundred years?”

National Geographic Channel is currently in production on MARS, a global event series set to premiere November 14. Join the journey at MakeMarsHome.com. #CountdownToMars

And for those wondering whether we should go at all, the reason for Musk making Mars an imperative is simple.

“The future of humanity is fundamentally going to bifurcate along one of two directions: Either we’re going to become a multiplanet species and a spacefaring civilization, or we’re going be stuck on one planet until some eventual extinction event,” Musk told Ron Howard during an interview for National Geographic Channel’s MARS, a global event series that premieres worldwide on November 14.

“For me to be excited and inspired about the future, it’s got to be the first option. It’s got to be: We’re going to be a spacefaring civilization.”

Mars Fleet

Though he admitted his exact timeline is fuzzy, Musk thinks it’s possible humans could begin flying to Mars by the mid-2020s. And he thinks the plan for getting there will go something like this:

SpaceX Interplanetary Transport System Watch an animation of Elon Musk's vision for how to send humans to Mars.



It starts with a really big rocket, something at least 200 feet tall when fully assembled. In a simulation of what SpaceX calls its Interplanetary Transport System, a spacecraft loaded with astronauts will launch on top of a 39-foot-wide booster that produces a whopping 28 million pounds of thrust. Using 42 Raptor engines, the booster will accelerate the assemblage to 5,374 miles an hour.

Overall, the whole thing is 3.5 times more powerful than NASA’s Saturn V, the biggest rocket built to date, which carried the Apollo missions to the moon. Perhaps not coincidentally, the SpaceX rocket would launch from the same pad, 39A, at Kennedy Space Center in Cape Canaveral, Florida.

The rocket would deliver the crew capsule to orbit around Earth, then the booster would steer itself toward a soft landing back at the launch pad, a feat that SpaceX rocket boosters have been doing for almost a year now. Next, the booster would pick up a fuel tanker and carry that into orbit, where it would fuel the spaceship for its journey to Mars.

Once en route, that spaceship would deploy solar panels to harvest energy from the sun and conserve valuable propellant for what promises to be an exciting landing on the Red Planet.

As Musk envisions it, fleets of these crew-carrying capsules will remain in Earth orbit until a favorable planetary alignment brings the two planets close together—something that happens every 26 months. “We’d ultimately have upward of a thousand or more spaceships waiting in orbit. And so the Mars colonial fleet would depart en masse,” Musk says.

The key to his plan is reusing the various spaceships as much as possible. “I just don’t think there’s any way to have a self-sustaining Mars base without reusability. I think this is really fundamental,” Musk says. “If wooden sailing ships in the old days were not reusable, I don’t think the United States would exist.”

Musk anticipates being able to use each rocket booster a thousand times, each tanker a hundred times, and each spaceship 12 times. At the beginning, he imagines that maybe a hundred humans would be hitching a ride on each ship, with that number gradually increasing to more than 200.

By his calculations, then, putting a million people on Mars could take anywhere from 40 to a hundred years after the first ship launches.

And, no, it would not necessarily be a one-way trip: “I think it’s very important to give people the option of returning,” Musk says.

Colonizing Mars

After landing a few cargo-carrying spacecraft without people on Mars, starting with the Red Dragon capsule in 2018, Musk says the human phase of colonization could begin.

For sure, landing a heavy craft on a planet with a thin atmosphere will be difficult. It was tough enough to gently lower NASA’s Curiosity rover to the surface, and at 2,000 pounds, that payload weighed just a fraction of Musk’s proposed vessels. For now, Musk plans to continue developing supersonic retrorockets that can gradually and gently lower a much heavier spacecraft to the Martian surface, using his reusable Falcon 9 boosters as a model.

And that’s not all these spacecraft will need: Hurtling through the Martian atmosphere at supersonic speeds will test even the most heat-tolerant materials on Earth, so it’s no small task to design a spacecraft that can withstand a heated entry and propulsive landing—and then be refueled and sent back to Earth so it can start over again.

The first journeys would primarily serve the purpose of delivering supplies and establishing a propellant depot on the Martian surface, a fuel reservoir that could be tapped into for return trips to Earth. After that depot is set up and cargo delivered to the surface, the fun can (sort of) begin. Early human settlers will need to be good at digging beneath the surface and dredging up buried ice, which will supply precious water and be used to make the cryo-methane propellant that will power the whole enterprise.

As such, the earliest interplanetary spaceships would probably stay on Mars, and they would be carrying mostly cargo, fuel, and a small crew: “builders and fixers” who are “the hearty explorer type,” Musk said to Howard. “Are you prepared to die? If that’s OK, then you’re a candidate for going.”

While there will undoubtedly be intense competition and lots of fanfare over the first few seats on a Mars-bound mission, Musk worries that too much emphasis will be placed on those early bootprints.

“In the sort of grander historical context, what really matters is being able to send a large number of people, like tens of thousands if not hundreds of thousands of people, and ultimately millions of tons of cargo,” he says. “I actually care much more about that than, say, the first few trips.”

In short, his vision for establishing a settlement on Mars is more an endurance sport than a sprint.

Rocket Man

But Musk is used to that. In 2001, he founded SpaceX with one goal in mind: put humans on Mars. At the time, he recalls, he found himself thinking about why, after the successful Apollo missions to the moon, humans hadn’t visited Mars—or reached very far into space at all.

“It always seemed like we should have gone there by now, and we should have had a base on the moon, and we should have had space hotels and all these things,” he said to Howard. “I’d assumed that it was a lack of will … it was not a lack of will.”

Instead, resources devoted to space exploration were scarce, and government spaceflight programs couldn’t assume the kind of risk that a private endeavor could tolerate. With an accumulated fortune from his time at Paypal, Musk founded a company dedicated to building rockets and vastly improving the vehicles that form the foundation of an interplanetary journey.

Contracts with private clients and the U.S. government followed, and now SpaceX is working on a version of its Dragon capsule that can send humans to the International Space Station.

Over the years, the company has had many high-profile successes—including landing the first suborbital reusable rocket stages on land and at sea—and its share of failures, with rockets exploding on the launch pad or en route to orbit.

That’s no surprise for any big technology development. But putting humans on Mars is a completely different challenge from sending humans into orbit, or even to the moon, especially when the goal isn’t just a few casual trips.

“I think what we want to avoid is a replay of Apollo,” Musk says. “We don’t want to send a few people, a few missions to Mars and then never go there again. That that will not accomplish the multiplanetary goal.”

Funding Muskville

Musk’s ultimate vision of a second, self-sustaining habitat for humans in the solar system is grand and lofty, but by no means unique. What makes Musk’s plan stand out from centuries of science fiction is that he might actually be able to make it happen—if he can bring costs down to his ideal levels.

“Entrepreneurs are able to look at questions that we think about, but we’re not quite ready to go there yet, things like supersonic retrograde propulsion,” said NASA administrator Charlie Bolden during a panel at the IAC.

"I think we can quibble over the numbers and the dollars and the timeframes and all, but we shouldn’t lose the fact that this guy went out on the international stage today and just laid it all out on the line," Braun adds. "I found it refreshing."

But for Mars to be a viable destination, Musk says the cost of the trip needs to come down to about $200,000, or the average price of a house in the United States. Trouble is, that’s a significant decrease from current cost estimates.

Musk doesn’t anticipate being able to do all of this on his own and said to Howard that some sort of synergistic relationship between governments and private industry will be crucial.

View Images Elon Musk at the Dragon 2 unveiling in May 2014. Photograph by Jae C. Hong, AP

“I think we want to try to get as much in the way of private resources dedicated to the cause, and then get as much as possible in the way of government resources, so that if one of those funding sources disappears, things continue.”

But combining different management styles, abilities to assume risk, sources of funding, and working with old institutional road maps will be a challenge, to say the least.

How might that all work? “With difficulty,” says space policy expert John Logsdon, professor emeritus at The George Washington University. “It will involve breaking things.”

For instance, reaching Mars in the 2020s will require a bit of a kick in the pants for SpaceX on the technology front. The massive rocket featured in the simulation is much more powerful than anything in the company’s current arsenal. The first iteration of that futuristic rocket, a gargantuan stepping stone known as the Falcon Heavy, has already been delayed for years.

These types of delays are one of the reasons why space policy experts are skeptical about the timing of Musk’s plan, which he acknowledges is murky at best.

“Based on past performance, I don’t know how you could say, well, yeah he’s missed all these other deadlines, but this time he’s gonna do it,” Logsdon says. “So I think the reasonable posture is that I’ll believe it when he does it.”

If humans do manage to touch down on Mars, Musk thinks the momentum from such an achievement will propel additional developments, just as early explorers searching for glory, gold, and spices drove improvements in ship technology and global industry.

Ultimately, Musk believes this kind of endeavor will bring Mars out of the realm of science fiction and transform it from a world fraught with difficulty and danger to one that humans might actually enjoy living on—including Musk.