Scientific Method / Science & Exploration

Confirmed: F-1 engine salvaged from ocean floor is from Apollo 11 rocket

Timely discovery coincides with 44th anniversary of first lunar landing tomorrow.

Back in March, we reported on founder Jeff Bezos' company Bezos Expeditions, which raised a significant amount of Saturn V F-1 engine components from the floor of the Atlantic ocean. Bezos Expeditions suspected that many of the components they had recovered belonged to not just any Saturn V, but to SA-506—the rocket that carried three men to humankind's first moon landing in July of 1969.

In a blog post this morning, Bezos Expeditions confirmed that careful analysis has revealed a faintly visible serial number stamped on several parts of one of the recovered thrust chambers. That serial number—2044—corresponds with F-1 engine number F-6044, which was installed in the center position as engine #5 in SA-506.

Bezos Expeditions

Recovery of anything from three miles beneath the ocean's surface is a significant achievement, of course, but the very rocket engines that flew humans to their first lunar landing are obviously of particular historical importance. Bezos and his company plan to restore the components to construct at least one museum-quality engine for public display.

Enlarge / Apollo 11 and Saturn V number SA-506, moments after lift-off.

The F-1 remains a monumental technical achievement, and one that is still being studied today. Each of the Saturn V's first stage F-1 engines gulped one ton of fuel and two tons of oxidizer per second, and they produced a staggering 1.5 million pounds of thrust. At peak thrust, the Saturn V's five F-1 engines together produced the equivalent of 60 gigawatts of energy—roughly equal to the peak electricity demand of the entire United Kingdom.

For all its power, engine F-6044 burned in flight for only about two minutes—right at 120 seconds, give or take a few. In those two minutes, the first stage burned more than four and a half million pounds (about two million kg) of propellant. In fact, engine F-6044 in its central #5 position would have been turned off about thirty seconds before the other four, which cut out at about the 150 second mark. The engines burned so much fuel so quickly that their monstrous thrust quickly gained the ability to push the Saturn V to unsafe levels of acceleration as the launch vehicle burned away fuel mass during launch.

At 1:50, the first stage of rocket SA-506 cut off, explosive charges separated it from the upper stages, and retrorockets mounted at its base fired to pull it away from the rest of the stack. From there, SA-506 followed a ballistic trajectory, silently arcing higher before beginning its long fall to the waters off of the coast of Florida.

Video from aft-facing cameras on the unmanned Apollo 4 test flight, showing the S-IC stage falling away toward Earth.

And there the engine has waited, under three miles of water, until now. We'll continue to keep tabs on the restoration effort as it progresses under the eyes and hands of engineers at the Kansas Cosmosphere and Space Center.

Listing image by Image KSC-69PC-442, courtesy NASA

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