Markings on one of the Saturn 5 rocket engine thrust chambers recovered from the bottom of the Atlantic in March read Bezos Expeditions

That's one small serial number on salvaged hardware, one giant leap for space history: Amazon.com billionaire Jeff Bezos says markings on one of the rocket engine components recovered from the bottom of the Atlantic in March confirm that it came from Apollo 11's first stage.

"Forty-four years ago tomorrow, Neil Armstrong stepped onto the moon, and now we have recovered a critical technological marvel that made it possible," Bezos said Friday in an update to his Bezos Expeditions website.

Bezos suspected that the F-1 engines came from the mission that delivered humans to the moon for the first time in 1969, but he held off from confirmation until the evidence could be documented.

That evidence, in the form of serial numbers, had been hidden by heavy corrosion on the parts. The rocket components were part of a five-engine complement that pushed the Saturn 5 rocket off its launch pad at Kennedy Space Center in Florida. The engines, along with the rest of the rocket's first stage, were jettisoned minutes after liftoff and made a fiery plunge into the Atlantic, where they sat for more than four decades.

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Bezos, a space enthusiast who founded the Blue Origin rocket venture, backed a months-long effort to recover the engines. The hardware was sent to the Kansas Cosmosphere and Space Center for conservation.

"One of the conservators who was scanning the objects with a black light and a special lens filter has made a breakthrough discovery – '2044' – stenciled in black paint on the side of one of the massive thrust chambers," Bezos wrote on Friday. "2044 is the Rocketdyne serial number that correlates to NASA number 6044, which is the serial number for F-1 Engine No. 5 from Apollo 11."

Bezos said "the intrepid conservator kept digging for more evidence, and after removing more corrosion at the base of the same thrust chamber, he found it – 'Unit No 2044' – stamped into the metal surface."

Any piece of a flown Apollo moon rocket would be a plum for any museum, but the fact that the thrust chamber played a part in the very first lunar landing is likely to add to its cachet. Enough components were recovered to produce two engine exhibits — one for the Smithsonian Institution's National Air and Space Museum, and one for Seattle's Museum of Flight.

The Cosmosphere's president, Jim Remar, says he expects the conservation work to be finished by 2015.



Update for 3:34 p.m. ET: Are all of the engine components that were recovered from the ocean floor from Apollo 11? Robert Pearlman, editor of the CollectSpace website, counsels caution.

"It may be too soon to say that all the F-1 engine components raised by Bezos came from Apollo 11," he said in an email. "It may be that other parts are from the same No. 5 engine, or other Apollo 11 engines, but depending on where they were recovered, they could be from other Saturn 5 launches. I think we will need to wait until additional serial numbers are found on the other components to say for sure. Still, if they raised only one part from Apollo 11, the thrust chamber is definitely an impressive part to behold!"

More about space history:

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.