The Apollo 11 moon landing, 45 years on: Looking back at mankind's giant leap

On July 20, 1969 -- 45 years and one day ago -- Neil Armstrong became the first human to walk on the Moon. Buzz Aldrin would soon follow suit and climb down the ladder of the Apollo 11 Lunar Module (the Eagle), and the pair would then spend two and a half hours being the first ever humans to explore the surface of another world. It's funny, but also a little bit sad: More than four decades later, Apollo 11 and the six further landings between 1969 and 1972 are still some of humanity's greatest technological achievements. In the years since, with political objectives sated and the Cold War diffused, funding for space exploration has all but dried up.

For now, though, let's take a retrospective look at some of the awesome photos from Apollo 11, and explore some of the fun (and perhaps lesser-known) factoids from the mission.

The sheer size (and cost) of the Apollo program

When you think of Apollo 11, the first thing that probably comes to mind is Neil Armstrong's fateful first words from the Moon: "That’s one small step for man, one giant leap for mankind." It's important to remember, though, that Apollo 11's Moon landing was the culmination of decades of work by hundreds of thousands of people working across dozens of science, technology, and engineering disciplines.

Back in 1973, the total cost of the Apollo program reported to Congress was $25.4 billion. By far the most expensive parts of the mission were the Apollo spacecraft (the Command Modules, the Lunar Modules) and the monstrous Saturn V launch vehicles. A single Saturn V launch cost up to $375 million in 1969 -- or, in today's money, a few billion dollars.

In 2009, NASA looked back at the cost of the Apollo program in its entirety, and arrived at a figure of $170 billion in 2005 dollars (or around $200 billion in today's money). Compare these costs to modern day space travel, where companies like SpaceX charge just $133 million to launch a spacecraft to the International Space Station. The Falcon Heavy, which will be comparable to the Saturn IV, will be in the same price region.

Whether the Apollo program was worth that kind of expenditure is a question that has been argued about for decades. NASA's funding peaked at a massive 4.4% of the federal budget in 1966. Between 1975 and 2000 it has generally floated at around 1% of the fed budget, and since the mid-90s it has slowly declined to just 0.5%.

The technological legacy of the Apollo program

While the Apollo program pushed the state of the art forward in many different disciplines, the most significant was NASA's pioneering research into integrated circuits. Prior to Apollo (and also the closely related Minuteman intercontinental ballistic missile, ICBM), the smallest computers were the size of a room. The Apollo Command Module and Lunar Module obviously couldn't house a room-sized computer, and so NASA -- working with MIT and Fairchild Semiconductor -- created the Apollo Guidance Computer. The AGC was one of the first computers to use integrated circuits (i.e. computer chips), and using bleeding-edge resistor-transistor logic (RTL) they managed to get the clock speed up to a fantastic 2.048MHz.

The entirety of the AGC's software, which managed primary guidance, navigation, and control of the spacecraft's various systems, was squeezed into just 36 kilowords of ROM (about 72 kilobytes in modern-day terms).

Other technologies that were invented or helped along by the Apollo program include: Heat resistant materials, the cordless vacuum cleaner, and freeze drying.

Live, from space

Not only did NASA manage to put two men on the Moon, and then get them (and Command Module pilot Michael Collins) back to Earth in one piece, but it also managed to live stream the whole thing to everyone on Earth with a television set (video above). I think that's one of the reasons the Apollo 11 Moon landing was so impactful: at least 600 million people watched Armstrong and Aldrin climb down the ladder of the Lunar Module and bounce around on the Moon.

Of course, getting a video and audio feed from the Moon back to Earth was no mean feat in 1969. The television camera used by Aldrin and Armstrong was initially mounted outside the Lunar Module, where it captured Armstrong's first steps on the Moon. The camera was then picked up and mounted on a tripod about 70 feet (20 meters) away from the Lunar Module. The camera is notable because it used the slow-scan television (SSTV) standard to transmit data back to Earth, rather than a broadcast standard like NTSC or PAL. SSTV only requires a tiny amount of bandwidth (a 3KHz voice channel), so it was ideal for long-distance transmissions from the Moon -- but with the caveat that it can take several seconds to transmit a single still image. Most of the SSTV footage was picked up by the Parkes radio telescope in Australia, which had a better view of the landing site than the Goldstone radio telescopes in the US.

Somewhat amusingly, slow-scan TV was incompatible with broadcast TV, so the footage that everyone saw on July 20, 1969 was from a broadcast TV camera pointed at a slow-scan TV set. This is why all of the broadcast TV footage of the Moon landing is low quality. Not so amusingly, the original, high-quality slow-scan TV footage was erased by NASA in the 1980s -- NASA was facing a "major data tape shortage" at the time and needed to reuse some tapes.

To this day, incidentally, NASA maintains that Neil Armstrong originally said, "That's one small step for a man, one giant leap for mankind," but the a was obscured by static. This is fairly plausible, given there was a storm near Parkes observatory. Since then, though, even Armstrong himself has admitted(Opens in a new window) that he simply flubbed the line -- fair enough, I think, considering the stress he was under.