Although we are celebrating the 40th anniversary of the first lunar landing, for many 21 December 1968 is the more important date. It was then that man first left the confines of Earth, when Apollo 8 became the first manned spacecraft to travel moonward. To some, this was the greatest achievement of the Apollo programme; astronauts Borman, Lovell and Anders were the first to see the Earth as a planet. Each hour, it had receded a little more into the great cosmic dark. But for the public and the politicians it was actually setting foot on the Moon that mattered, and, just after Apollo 8 made its triumphant return, the crew of the first lunar landing mission were selected.
Even as Armstrong and the crew of Apollo 11 walked on the Moon, Nasa's budget was being cut. At an Apollo party, President Nixon said "Here's to the Apollo program. It's all over." In a way he was right. Apollo had become a closed ambition, and, having beaten the Soviets, the politicians couldn't see what else there was to do. Nasa had enough hardware for nine more landings leading up to a grand finale: Apollo 20 and a touchdown in the dramatic Copernicus crater.
Apollo 12 descended into the Ocean of Storms, and when Charles Conrad stood on the surface he spotted Surveyor 3, which had landed two and a half years earlier. When Apollo 12 returned, Apollo 20 had been cancelled and 18 and 19 looked uncertain. Apollo 13 limped back to Earth having suffered an explosion that destroyed all hopes of a landing. Until that drama, public interest in the mission was low. Keeping the crew alive for 87 hours, their only protection thin flight-suits as the interior temperature dropped to that of a refrigerator; their fatigue; the wet and clammy capsule which saw them through the fiery re-entry – this was a tour de force that gripped the world.
When they returned, however, the White House let it be known that, henceforth, space exploration no longer held such a high position in the national list of priorities. The hopes of a manned flight to Mars were gone, and the space shuttle and space station were in peril.
In 1971, Apollo 14 landed in the Fra Mauro highlands, touching down on material ejected billions of years ago from the great Imbrium basin, 400 miles to the north. With Apollo 15, the programme really hit its stride. It landed near a vast chasm in the lunar surface called Hadley Rille. During a Moon walk, David Scott saw a small white rock which he immediately recognised as anorthosite – part of the Moon's primordial crust, the so-called Genesis rock, which is 4.5bn years old. Apollo 16 touched down in the central highlands in April 1972, Apollo 17 in a steep canyon in December of the same year. And then it was over. The cold grey Moon was alone again.
But, apart from history, what did Apollo leave us? It inspired a generation to become involved in an engineering feat that fertilised many areas of American industry: microelectronics, computers, avionics and advanced materials all benefited from the missions. Indeed, extraordinary manufacturing processes had to be developed to produce the mighty Saturn 5 rocket. Years later, President Bush senior said that Apollo was the best return on an investment since Leonardo da Vinci bought a sketchpad. Apollo, more than any other space project, showed us where we live in the universe, and started the global ecological awareness that lives today. And, of course, Apollo also gave us the Moon.
Thanks to Apollo and a few other space programmes, we know more about the Moon than we do about any other object in space, with the exception of our own planet. We have 2,000 samples from nine sites, 382kg from the six Apollo landings, as well as 0.3kg from three Soviet automated sample-return probes. The samples tell us that the Moon is rich in minerals and has in its rocks geological wonders and a record of the solar system's history. Apollo taught us that the Moon was probably formed from the debris thrown into space when an object the size of Mars struck the proto-Earth when the Sun was young.
Following Apollo, the US and the USSR turned away from the Moon. The USA looked to Mars and the outer planets, as well as the space shuttle and the space station; the USSR to Venus and to their space stations. It wasn't until 1990 that the Japanese probe Hiten returned to the Moon, followed by the US Clementine mission and in 1998 the US Lunar Prospector. It was these later missions that changed many minds about the Moon. Prospector found evidence of water ice in the dark depths of polar craters that never receive any sunlight. The Moon still had secrets that surprised those who took a "been there, done that" attitude.
In 2004, President Bush reshaped Nasa's priorities, saying the space shuttle should be retired, and a replacement built which would send astronauts back to the Moon by 2020. In the following years, other nations took an interest as the Moon underwent a renaissance. Craft were sent by the European Space Agency, China, India and Japan. Recently, the USA launched the largest and most sophisticated probes ever sent to the Moon. And more unmanned probes are planned in the years ahead.
But what of the next "small step" on the Moon? The present plan calls for a June 2019 touchdown of the Altair landing craft as part of the Orion 15 mission, which will stay on the moon for a week. Recently, Nasa chose a handful of new astronauts for training and some of them may be onboard.
When we return, we will probably go to the "peak of eternal light". This is the north-facing lip of a crater near the lunar south pole. It is in sunlight for all but a few hours every month because from this part of the Moon the Sun skirts the horizon and never truly rises or sets. It's a perfect position for solar panels to generate electricity. Next to the peak of eternal light are the craters of eternal night; as the name suggests, there is nothing like it on any other world in our solar system, and in their endless shadows may be ice deposits.
In lunar rocks there is everything required for supporting life – and many industrial processes, too. It's all there: hydrogen, aluminium, iron, helium and oxygen. The possible discovery of ice at the lunar poles changed everything. Before, it was thought that hydrogen was the scarcest commodity on the Moon, but now that ice has been detected the economics of a lunar outpost have changed dramatically. Water – oxygen and hydrogen – is also rocket fuel.
When the history of the exploration of our Moon is written, historians will recall the first landings and a lull before we returned. Generations have grown up without the inspiration of watching a live landing on the Moon. That will change. Soon, schoolchildren will log on to the lunar base website for science lessons from the Moon and go on virtual reality Moon walks – and, once more, they will dream of being astronauts themselves.
Dr David Whitehouse is author of 'One Small Step: Astronauts in their own words' (£15), published on 9 July by Quercus. To pre-order a copy for £13.50 (free P&P) call Independent Books Direct on 08700 798 897, or visit independentbooksdirect.co.uk