Saturn V rockets

Genesis

The Saturn V (‘Saturn five’) that took Apollo astronauts to the Moon was the most powerful rocket ever made. It was the culmination of the Saturn rocket series developed at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

Over 1960–62 the Marshall Space Flight Center developed rockets C-1 to C-4, later renamed the Saturn series. The first of these rockets pioneered the use of multiple stages, each of which could be jettisoned after its fuel was spent.

The Apollo 11 Saturn V rocket lifts off from Kennedy Space Centre July 16, 1969.

The Apollo 11 Saturn V rocket lifts off from Kennedy Space Centre July 16, 1969. Credit: NASA

The design of the rocket to go the Moon depended on just how the astronauts were to reach the Moon’s surface. After much debate, NASA opted for ‘lunar orbit rendezvous’: a command module would go into orbit around the Moon, while a lunar module would descend to the surface then ascend to meet the main craft. This plan was settled by January 1962, letting NASA announce that production would begin on the Saturn C-5 (now called the Saturn V).

Construction

In the form used for the Apollo missions, the Saturn V was a three-stage rocket. It was as high as a 36-storey building and gulped 13 tonnes of fuel a second upon lift-off.  The first stage had five F-1 engines producing a calculated thrust of 3.4 million kg (7.5 million pounds). The second stage’s five J-2 engines created 454,000 kg (1 million pounds) of thrust, and the single J-2 engine of the third stage a respectable 102,000 kg (225,000 pounds).

The Marshall Space Flight Center designed the rocket’s stages; external contractors constructed the flight versions. Boeing built the first stage (S-IC) and was also responsible for the assembly and integration of the three stages. North American Aviation built the second stage (S-II) and Douglas Aircraft the third (S-IVB), while IBM delivered the instrument unit controlling the rocket.

A cutaway diagram of the Saturn V launch vehicle showing the three stages, instrument unit, and Apollo spacecraft.

A cutaway diagram of the Saturn V launch vehicle showing the three stages, instrument unit, and Apollo spacecraft. Credit: NASA

The engines for all three stages were built by North American Aviation’s Rocketdyne division (which later became part of North American Rockwell).

Armed only with slide rules, these companies’ engineers wrestled with their huge task. The first few test firings of the stage one engines broke windows in downtown Huntsville. Unstable combustion threatened to explode the engines, until the engineers found a new way to inject the fuel. The builders of stage two, in California, had trouble applying insulation: they turned to surfboard makers for help. When welding was difficult, the engineers redesigned the welding machines. When equipment blew up under test, they patiently tracked down the fault and redesigned the failed part.

Launch

The first test of the complete Saturn V was the launch of Apollo 4, on 9 November 1967. The rocket had well over a million parts, and they all had to work together.

The massive F-1 engines used on the Saturn V.

The massive F-1 engines used on the Saturn V. Credit: NASA

They did. It was a textbook flight.

The second launch, Apollo 6, did not go to plan. Two engines shut down. The rocket limped into orbit, but only just.

Kennedy had said his country would have a man on the Moon within a decade. By December 1968 NASA was under pressure to put men into orbit around the Moon. This mission, Apollo 8, was the third flight of the Saturn V. The rocket was also used for Apollo 9 and 10, which tested the lunar lander.

The next launch, on 16 July 1969, was Apollo 11.

The Saturn V was used for the rest of the Apollo missions too, and never failed to deliver.

The size of the Apollo 11 Saturn V rocket compared to some of Australia’s biggest antennas.