WHEN the Saturn V moon rockets blasted off from Cape Canaveral in Florida, their flight paths took them east, over the Atlantic ocean. The Saturns were made up of three stages. When the first had used up all its fuel, two and a half minutes into the flight, it was unceremoniously jettisoned and left to splash into the sea, safely away from any human habitation. The rocket stages, and the engines that were attached to them, have sat in their watery junkyard for almost half a century. Now, though, they are beginning to return. On March 20th, in a blog post, Jeff Bezos, the founder of Amazon and a confirmed space cadet, announced that his project to bring some of the Saturn’s mighty F1 engines back to the surface had been successful.

It is an impressive feat of engineering, reminiscent of the effort that located the wreck of the RMS Titanic in 1985. NASA’s flight data gave Mr Bezos’s team a rough location to begin the search. They then used sonar to pinpoint the engines’ precise locations. Undersea robots, similar to those used to investigate the Titanic, were sent down through more than 4,000 metres (13,000 feet) of water to confirm the find.

There are a few caveats. It seems Mr Bezos has not managed to recover any complete engines, though he reckons he has enough pieces to cobble together two complete examples. The original goal had been to recover the engines from the most famous flight of all—Apollo 11, whose crew became the first humans to walk on another celestial body. But time, salt water and the effects of smashing into the sea at high speed have left the engines battered and bruised, and the serial numbers on their components (which would enable NASA to identify the specific rocket from which they came) cannot always be read.

When the future becomes the past

Nonetheless, it is the most impressive feat of the new—and poignant, or ironic—field of space archaeology. Space travel has been synonymous with the idea of the future for over a hundred years. The Saturns themselves were in many ways out of their time. At 111 metres tall, they were the size of a small office building, and even half a century later they remain the most powerful rockets ever to have flown. Yet these days, the future that the Saturns represented has become an object of study for those who investigate the past, as the heroic space age dreamed of by science-fiction authors since Jules Verne has resolutely failed to materialise. Ever since the cancellation of the Apollo programme in 1970, astronauts have been stuck in low Earth orbit.

There are plenty of others besides Mr Bezos who are keen to investigate and preserve that vanished future. In 2011, for instance, NASA released high-resolution pictures from its Lunar Reconnissance Orbiter spacecraft, showing the various Apollo landing sites, as well as some of the robotic craft sent to the moon in the 1970s by the Soviet Union. A team of amateur astronomers is attempting to locate the ascent stage of Snoopy, Apollo 10's lunar module, which (intentionally) did not actually land and which was abandoned into a sun-circling orbit. And, spurred by the lunar ambitions of China, as well as by the prospect of visits by privately financed robotic spacecraft under Google’s Lunar X Prize, NASA last year released a document requesting that any new visitors to the moon keep their distance from the Apollo landing sites, in order to "protect lunar historic artifacts".

As for Mr Bezos’s engines, they remain the property of NASA. Raising them from the ocean floor was a passion project. If they can be reassembled, he intends to put them on public display. One will presumably end up at the Smithsonian National Air and Space Museum in Washington, with the other perhaps going to the Museum of Flight in Seattle, near where Mr Bezos lives. There they will join the dusty spacesuits, scorched crew capsules and model rockets that mark a future that never quite came to be.