December 2022 marks an important anniversary. It’s been 50 years since humans last travelled to the Moon.
The original NASA Apollo program planned to land nine missions on the Moon. In the end, just six crewed Lunar Modules made it to the Moon’s surface. It started with Apollo 11 in July 1969 and stopped with Apollo 17 in December 1972. (If you’ve seen the Tom Hanks movie, you’ll know Apollo 13 suffered a mishap and orbited the Moon once but never landed. Apollo 8 orbited the Moon in December 1968 and Apollo 10 in May 1969 as successful test flights. Neither mission attempted to land on the Moon.)
If you’re ever asked in a pub trivia how many astronauts walked on the Moon – the answer is twelve!
A further three Apollo missions – Apollo 18, 19 and 20 – were originally scheduled but were cancelled in 1970.
After Apollo 17, NASA launched several Earth orbiting missions to Skylab and the Apollo-Soyuz mission with the USSR. However, no humans have ventured beyond Earth orbit since 1972.
Apollo 17 lifted off on the 7th of December 1972 with the first night launch of a Saturn V rocket. It splashed down in the Pacific Ocean on the 19th of December 1972 after spending three days exploring the Taurus–Littrow valley. A notable inclusion in the Apollo 17 crew was Harrison Schmitt, the only professional geologist to travel to the Moon.
Dr Harrison Schmitt on the surface of the Moon during the Apollo 17 mission
Why did the Moon landings stop at Apollo 17?
There’s been millions of words written about the Apollo program, and this has always been a thorny question, but the short answer is money. Sending each rocket to the Moon was an extraordinarily expensive undertaking. The Apollo program cost around USD$26 billion dollars, which is some USD$260 in today’s money.
From the public’s point of view, the main reason for going to the Moon was to “beat the Russians”. This had clearly been done, so why spend any more money? Public interest in the missions after Apollo 11 waned quickly, even if the drama of the rescue of Apollo 13 captured global attention. Once travelling to the Moon became routine, it ceased being newsworthy. The Vietnam war was raging, and global conflict was threatening.
(A number of prominent figures have also suggested NASA was also worried about losing further missions and astronauts.)
What did the Apollo program achieve?
There were a number of major “firsts”
From a geo-political perspective, the “space race” allowed a head-to-head contest between the USA and USSR to take place from 1957 to 1969 without resorting to an armed conflict.
Secondly, the entire Apollo spurred several technological advances that no doubt would have occurred in time but were pushed along with such a massive infusion of government funds. People might jokingly mention non-stick Teflon frying pan coatings and “Tang” juice mix as being the main but products of the space race. However huge leaps in electronics, miniaturisation and microchips were needed to get Apollo to the Moon. Had the Apollo program not taken place, our day-to-day world might look very different to the way it is today.
A major scientific legacy of the Apollo program was the discovery that planets do not form cold. Prior to Apollo, planets were thought to form from an accumulation of material. Apollo found the Moon was molten at some point allowing a planet wide sea of magma that allowed minerals like plagioclase to float atop it. This revolutionised our idea about planetary formation.
Can I see the Moon landing sites with my telescope?
Yes. All Apollo landings took place on the side of the Moon that faces the Earth. You can see where each mission landed.
Apollo landing sites. Image via NASA
You cannot see Apollo hardware left on the Moon, including the descent stages of the Lunar modules with any telescope. They are too far away and too small. Traces of the Apollo 17 landing including astronaut’s footprints were spotted by NASA’s Lunar Reconnaissance Orbiter (LRO).
Apollo 17 landing site. Image via NASA
Unless beaten the by SpaceX or another private space company or national space program, the earliest NASA plans to return humans to the Moon will be on the Artemis 3 Mission scheduled for 2025.