One year after announcing an intrepid plan that he claimed could put a million people on Mars by the 2060s, Elon Musk is fine-tuning his roadmap for putting humans on the red planet.
In a somewhat disjointed presentation at the International Astronautical Congress in Adelaide, Australia, on September 29, Musk outlined an edited version of his original scheme. His final vision didn’t change much, but he did highlight revisions to a planned 42-engine rocket Musk has nicknamed the BFR, as well as a vague proposal to pay for that rocket by using it to deliver satellites into orbit and to service the International Space Station.
Plus, in future years, the BFR’s targets may multiply. Musk suggested that the rocket could also be used to transport people between any two points on Earth in less than an hour— or perhaps help build an outpost on the moon.
“This will enable the creation of a lunar base. It’s 2017. We should have a lunar base by now. What the hell’s going on?” said Musk, who founded SpaceX and Tesla Motors.
Musk has spoken frequently about his desire to die on Mars—just not on impact—and his belief that for humans to survive, we must become a multi-planet species. At the same conference last year, which was held in Guadalajara, Mexico, Musk outlined his highly anticipated strategy for achieving that existential imperative by settling Mars.
The first iteration of the Interplanetary Transport System relied on the BFR, a humongous 42-engine rocket roughly 400 feet tall when completely assembled. That rocket’s booster would act like a much larger version of the reusable Falcon 9 rockets that SpaceX has already started flying, repeatedly delivering fuel tankers and spaceships capable of carrying up to 100 passengers into Earth orbit. (We’ve had robots on Mars for 20 years straight—and they’ve taken outstanding photos.)
Ultimately, Musk had envisioned as many as a thousand spaceships in a holding pattern in orbit around Earth. Then, every 26 months or so when Earth and Mars favorably aligned, that fleet of ships would sail toward our nearest neighbor, unfurling solar panels along the way.
After a journey lasting three to six months, those ships would fire up some supersonic retrorockets and gently land on the Red Planet, depositing human cargo and supplies. (Musk hasn’t yet specified how all those humans will survive once they’ve landed on a world with noxious soil and a suffocating atmosphere.)
This year’s revision downsizes the BFR to something that’s only a bit larger than the Saturn V rocket, which propelled astronauts to the moon during the Apollo era. To be clear, BFR 2.0 is still huge: It can carry a cargo payload with a living space that’s eight stories tall and holds more volume than an Airbus A380’s passenger cabin. It also sports a snazzy fin on the back that will help it land on bodies with thick, thin, or no atmosphere, which vastly increases its usefulness across the solar system.
Musk anticipates beginning construction on the rocket within the next year. He adds that it’s not entirely implausible for two such vehicles containing just cargo to launch in 2022. That may not sound like too far from now, but “five years seems like a long time to me,” Musk says.
If SpaceX meets that deadline, Musk says the company would next aim to launch four vehicles in 2024: two containing cargo, and two containing crew. The two missions would be tasked with finding Mars’s best sources of water and constructing a propellant plant on Mars, which SpaceX would need to sustain round-trip journeys between Earth and Mars.
He Doesn’t Think It’s Gonna Be a Long, Long Time
Downsizing that giant rocket isn’t an entirely unexpected move.
Musk is known for being ambitious; SpaceX is the first company to reliably reuse portions of rockets, Tesla’s electric cars (models S3X and the forthcoming Y) have waiting lists several years long, and the Hyperloop—which could whittle travel time between San Francisco and Los Angeles to a paltry 45 minutes—is in development.
But his timelines have generally elicited a bit of an eyeroll from some spaceflight experts who know not to necessarily trust his projected deadlines. As an example, SpaceX has promised to roll out the big, bad Falcon Heavy rocket for years. But that rocket, which plays a crucial role in Musk’s plans to send humans around the moon and put a lander on Mars in 2018 – hasn’t been tested yet.
Perhaps responding to some of the criticism about delays, Musk wryly noted that the 2022 first launch date was not a typo—but acknowledged that it is “aspirational.”
“While the timeline and capabilities are certainly ambitious, I’m bullish on U.S industry's ability to carry out challenging and far-reaching goals,” says the University of Colorado, Boulder’s Bobby Braun, who is NASA’s former chief technologist. “It’s great to see the private sector lead in this way, and I hope we see more of it.”
Musk’s Mars dream is audacious, to say the least. But achieving it wouldn’t require unprecedented technical innovation. The science and engineering are set on solid foundations, and already, Braun notes that SpaceX has achieved portions of the plan that once sounded beyond bold, such as reusable rocket boosters.
“It’s this type of pragmatic and continuing technology advancement that could open up the solar system in new and fascinating ways to humanity,” he says.
Instead, one of the major hurdles is financial. SpaceX simply doesn’t have enough cash to fund the venture on its own, and convincing public or private partners to buy in isn’t exactly as easy as running on Mars, where gravity is about one-third that of Earth’s.
Musk addressed that point, too.
“I think we’ve figured out how to pay for it,” he said. “This is very important.”
Right now, that scheme involves building a pile of Falcon 9 and Dragon capsules, and selling as many rides to space as possible for cargo missions.
Within a few years, Musk says, all of SpaceX’s resources will turn toward building BFR—which he says could transport humans around the world in less than an hour, or even ferry us to the moon. “We believe that we can do this with the revenue that we receive for launching satellites, and of re-servicing the space station,“ he adds. (See SpaceX’s spacesuit of the future.)
One Planet, Two Planets, Red Planet, Blue Planet
But parking humans on Mars also poses major ethical concerns that Musk did not address—among them, the possibility that we and our hardware might contaminate the planet. This could either damage any life that’s already on there, or erase any chance we have of finding out whether alien life forms were ever there at all. (Find out how going to Mars could mess up the hunt for alien life.)
Putting humans on Mars is only the first step toward settling the planet. It also needs to actually be habitable. By human standards, Mars is lethal right now: It has air we can’t breathe, toxic soil, and water that’s locked into subsurface ice deposits.
In the past, Musk has acknowledged this problem and proposed terraforming Mars into a lush world capable of supporting life. His method of choice? Nuking the planet’s poles and releasing all the water currently locked into buried ice deposits.
Such drastic action would likely be catastrophic for any life that had managed to make Mars home before humans showed up. Lucianne Walkowicz, the Library of Congress’s chair of astrobiology, has said that using another world as a backup planet—and destroying it in the process—is a deeply flawed idea.
“There are many excellent reasons to go to Mars, but for anyone to tell you that Mars will be there to back up humanity is like the captain of the Titanic telling you that the real party is happening later on the lifeboats,” Walkowicz said during a TED talk on the ethics of Mars exploration last year. “If we can understand how to create and maintain habitable spaces out of hostile, inhospitable places on Earth, perhaps we can meet the needs of both preserving our own environment and moving beyond it.”
Editor's note: This article has been updated with additional comment.