The first space race of the 21st century has Mars as its finish line. While victory is still likely years, even decades away, Elon Musk and SpaceX have made the most tangible progress toward the red planet, and one person with plenty of first-hand expertise in all things space thinks the company could get us to Mars sooner than anybody would have guessed.

British astronaut Tim Peake, who has spent 185 days aboard the International Space Station, offered his thoughts on the future of Martian exploration at a recent event organized by the charity Aerobility. He said the first humans on Mars will likely get there in about two decades, if government agencies remain the main drivers, but there’s a chance private spaceflight could accelerate that timeline.

“Humans on Mars, I think will be the late 2030s,” said Peake. “That’s what the government space agencies and the International Space Exploration Group are working towards. It could be that some of [these people’s] programs bring that date forward. But, the late 2030s would be a realistic time frame. What could throw a big bowling ball through all that is commercial spaceflight.”

Musk and SpaceX aren’t the only players in the commercial field, of course. There are Richard Branson and Virgin Galactic, Jeff Bezos and Blue Origin, and more conventional private contractors for government projects, like Boeing and Lockheed Martin. But Musk’s company has raced ahead of its competitors in demonstrating the actual practical usability of its rocket technology, especially after last month’s Falcon Heavy launch.

“We have seen the ambitions of people like Elon Musk,” said Peake. “There are several other companies that also have ambitions to send people to Mars. I think that we will end up working very closely with these companies in public-private partnerships when we eventually go to Mars.”

That idea of public-private partnerships is an intriguing one. For his part, Musk has spoken exclusively about SpaceX when detailing his plans for Mars. A partnership with NASA on a Mars mission — perhaps one where NASA astronauts and terrestrial support staff conduct a mission using one of SpaceX’s planned BFR craft to get to the red planet — is certainly conceivable, but it’s not the plan right now.

Still, such a plan could prove the most effective way to combine SpaceX’s cutting-edge rocket tech with NASA’s institutional experience, but that’s not the plan right now. It’s also possible that NASA or another space agency — like Peake’s own European Space Agency — could team with another private spaceflight company, assuming Musk plans to go it alone.

The point is, though, that all those possibilities suggest an acceleration of government agencies’ current plans for spaceflight. If the set target is the late 2030s, it’s possible market competition could knock several years off that, especially if SpaceX can find the same success with the BFR that it did last month with the Falcon Heavy.