On December 21, 1968, millions of people flocked to Cape Canaveral and millions more sat glued to their TVs to watch Apollo 8 launch for the moon. It was the first time the mammoth Saturn V launch vehicle carried men, and must have been an awe-inspiring sight. At 363-feet tall and capable of generating over 8.7 million pounds of thrust, it was the workhorse designed specifically to take Apollo to the moon, and the technology that cinched the space race for the United States.

Seven years later the Saturn V was gone.

There are a lot of stories about why NASA's most powerful rocket disappeared from the line up of launch vehicles. Some propose that NASA didn't want to pay for a storage unit to keep all the relevant files. Moon hoax theorists love to suggest that the US government was so desperate to kill Apollo that the records were destroyed. Perhaps more likely is that the blueprints were stored in a system that's no longer accessible; or another common story that when Apollo was cancelled, the engineers left without consolidating relevant documents.

I didn't design the Saturn V – if I did I wouldn't be writing about its disappearance – so I can't say what happened to it. But I can speculate. My research into the Saturn V reveals an intricately complicated rocket built in pieces. The most probable reason the rocket is gone is because the handful of men who knew how the whole thing worked are also gone.

The Saturn V was conceived by Wernher von Braun's rocket team at the Army Ballistic Missile Association in 1960. Its sole purpose was to generate enough lift to send a spacecraft to the moon, and it did this through its three-stage design.

The first stage, the S-IC, provided raw power. 800,000 litres of refined kerosene and 1.3 million pounds of liquid oxygen (lox) fuelled five F-1 engines to produce 7.5 million pounds of thrust. The SI-C burned for a minute and a half, sending the spacecraft to an altitude of about 38 miles. With its fuel exhausted, the empty stage fell away, prompting the second stage to take over. The second stage, the S-II, used five liquid hydrogen and lox fuelled engines to produce 1 million pounds of thrust. The stage burned for 6 minutes bringing the spacecraft to an altitude of 114 miles. The third stage, the S-IVB, fired last. Its single liquid hydrogen and lox fuelled engine fired for 2 minutes and 45 seconds to bring the Apollo spacecraft to an orbital height of 115 miles.

The third stage fired a second time for five minutes and 12 seconds to propel Apollo to the moon, a manoeuver called the translunar burn.

But the Saturn V wasn't just powerful; it was highly sophisticated. Its designers gave it a certain degree of autonomy. The brain of the rocket was its instrument unit, a ring of computerized components situated above the third stage.

The most important part of the instrument ring was the stabilized guidance platform. The Saturn V's onboard guidance system was aligned to the "fixed" stars, enabling it to navigate in space without the need for any Earthly reference points.

This autonomous guidance platform also enabled the rocket to steer itself on its prescribed flight path without any input from the astronauts on board. Directional control was achieved through the arrangement of the first stage's five engines. The central engine was fixed, but the outer four could swivel to direct the rocket's thrust in the necessary direction.

With such sophistication comes complexity, and the Saturn V had a lot of moving parts that all had to work together. But before it could send a spacecraft to the moon, the main question facing the rocket's designer was who would actually build the mammoth launch vehicle?

With the aim of combining the greatest talent in the aerospace industry, von Braun enlisted the expertise of the best engineers in leading aerospace companies by giving each piece of the rocket to a different subcontractor.

Boeing built the first stage, North American Aviation (who built the X-15 and the Apollo command module) built the second stage, and Douglas Aircraft built the third stage. The inertial guidance system and instrumentation was built by IBM but managed by NASA's Marshall Spacecraft Centre – it made sense to keep the brains of the rocket close to the men who would program it for launch.

Development proceeded at an impressive speed. Each element was tested and the first complete or "all up" test of the Saturn V was in 1967 – it launched the unmanned Apollo 4 into Earth orbit.

The division of labour on the Saturn V's construction proved to be a bit of a double-edged sword. On one hand, it facilitated the rocket's completion in time for the end-of-decade moon-landing deadline; it is certainly responsible for the success of the Apollo program.

But on the other hand, employing so many subcontractors spread the knowledge of the rocket across a wide base. Meanwhile, the people who oversaw the actual assembly and understood the overall working of the Saturn V were few. Each contractor recorded the workings of their stage and records survive about the engines used, but only a handful of engineers from NASA's Marshall Spacecraft Centre knew how Saturn V puzzle fit together.

There are complete Saturn Vs on display in museums. From these it's possible to reverse engineer at least structural parts of the rocket. But this doesn't mean anyone could know how it worked. It's likely that the rocket will never see a rebirth and reuse in manned spaceflight.

Without a planned used for the Saturn V after Apollo, most of the comprehensive records of the rockets inner workings stayed with the engineers rather than the institution. Fascinating documents – the key to rebuilding Apollo's workhorse and realizing von Braun's dream of a Saturn V-assisted trip to Mars – may be living unknown in someone's basement in a pile of papers in a cardboard box.