A panel of administrative judges at an obscure federal agency ruled this week that a largely behind-the-scenes clash of billionaire entrepreneurs, which pits Elon Musk against Jeff Bezos, can continue.

The dispute centers on a patent awarded to Bezos’ Blue Origin space company that gives it the right to launch and then land rockets on a floating barge in the ocean. But Musk’s SpaceX, which earlier this year became the first company to attempt such a landing, challenged the patent, saying that the idea on how to pull off a landing at sea had been discussed in space circles for years.

Earlier this week, administrative patent judges at the U.S. Patent Trial and Appeal Board agreed with SpaceX's arguments—or most of them—and is allowing the issue to go to a full administrative hearing before the U.S. Patent Trial and Appeal Board.

Both companies declined to comment. Bezos, the founder of Amazon.com, also owns The Washington Post.

At stake is the right to pursue what many view as a potentially momentous breakthrough in space flight: the ability to launch a rocket into space, return it to Earth, and then launch it again as if it were a commercial air plane.

The ability to reuse rockets could dramatically lower the cost of space flight. And whoever is able to do it first could capitalize in a huge way.

While Musk, who founded Tesla Motors and Paypal, has pioneered many innovations in electrical cars and e-commerce, he is also keenly focused on rocket reusability. SpaceX has been working on the technology for years, and in January it attempted the unprecedented feat of landing the first stage of its Falcon 9 rocket on a floating barge it calls an autonomous spaceport droneship.

The rocket hit the platform and exploded. But even making it to the barge was considered something of a triumph, and the company is forging ahead with plans to try again.

If Blue Origin is able to hold on to its patent, SpaceX’s ability to carry out its plans could be cut short. But with the patent board’s ruling that seems unlikely, said Andrew Rush, a patent attorney specializing in aerospace who is not affiliated with the case.

He called it a “preliminary win” for SpaceX.

The ruling "doesn’t necessarily mean that SpaceX will succeed, it means there’s a reasonable likelihood of success,” he said.

In a separate decision denying two of SpaceX's claims, the judges said there was not enough specificity in Blue Origin’s patent, and therefore it could not reach a determination on them.

Before the patent fight, Musk and Bezos fought over which company would use a NASA launch pad at the Kennedy Space Center. After SpaceX won the lease, Blue Origin protested to the Government Accountability Office, but lost. And Musk took a shot at Bezos’s startup space company.

“If they do somehow show up in the next 5 years with a vehicle qualified to NASA’s human rating standards that can dock with the Space Station, which is what Pad 39A is meant to do, we will gladly accommodate their needs,” Musk wrote in an e-mail published at SpaceNews.com. “Frankly, I think we are more likely to discover unicorns dancing in the flame duct.”

The Blue Origin suborbital spacecraft, New Shepard, has never been launched into space, but Bezos has said recently that crewed flights could take place toward the end of this decade.

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