A short diversion for mankind: Christopher Priest on how, overnight, the Space Age dream became a yawn

THROUGHOUT my 1950s adolescence I lived in the certain knowledge that, as an adult, I would enjoy the Space Age. I grew up with Frank Hampson's futuristic Dan Dare artwork for Eagle magazine. This depicted a society based on what were then solid British values: interplanetary travel as it might be flown by the RAF, a social-democratic world government as it might be run from Westminster, plus technology (such as computerised newspapers emerging from slots in the wall) that never broke down. There was also Professor Jocelyn Peabody to look forward to. It was not just a possible future. It was the future. After all, the Great Powers were even then starting the race into space.

What neither I nor any of my contemporaries foresaw was that the Space Age - in which men flew to other worlds - would last just three years. It began 25 years ago this week, when men first landed and walked on the Moon. It ended in 1972.

This is not the official view, of course. The space shuttle and Mir are still flying, and orbiting telescopes, even as you read this, are peering at comets colliding with Jupiter. Men and women continue to venture into low-orbit space; communications satellites have transformed the way the world is run. Space is still with us, but the Space Age has passed because it never, in truth, came into being.

The Space Age really began for me - and I suspect for many other people - not with the Moon landing, but seven months earlier in December 1968, when three American astronauts flew aboard Apollo 8 to the Moon, circled around the back of it, then returned safely to Earth. It was a sensational voyage, now largely forgotten. It is, though, the one Nasa adventure that still has the power to move me. It was the first time that men travelled to a place from which, temporarily, they could not see Earth. Apollo 8 seemed to represent a symbolic step into the Space Age, a crossing of a spiritual threshold, which chimed with the Age of Aquarius.

But Apollo 8 also established some fundamental and more mundane conditions for human spaceflight, which held good for the Moon landing. First, it needed perfect or near-perfect technology: a rocket with millions of components that either did not fail or had back-ups on hand to avert disaster. It is hard to remember now how wondrous this seemed. When I was a child, technology was unreliable: televisions burst their tubes, cars their big ends. Now, cars, cameras, computers, domestic hardware are far more reliable. We expect a video recorder or fax machine to work as soon as we take it out of the box, and to continue doing so for several years.

Second, spaceflight needed human courage. We never doubted this; the shock was that astronauts seemed not to convey it. Courage is not a word in the astronaut lexicon. Last year, I worked with Helen Sharman, Britain's first astronaut, on her autobiography. I asked if she felt she was braver than other people. No, she said. A space mission relied on high levels of training, and teamwork between those who have trained together. Later, she described sitting in a Soyuz TM rocket during blast-off. She told her story of loud bangs, violent vibrations and dizzying views of the Pacific in a calm and matter-of-fact way; yet it kept me sleepless for the next three nights.

Third, and most important, there was television coverage. Few moments in human endeavour have been so widely anticipated as the first Moon landing. Science fiction writers had been describing it for years in innumerable novels and stories. Many of them forecast the techniques - the Moon landing craft, for example - with remarkable accuracy. But without exception they got one thing wrong. None of them foresaw that millions of people would watch the event live on television. For that, we can forgive Jules Verne and H G Wells, who wrote before television was invented, but not their successors.

Yet we can now see that the Moon landing was a quintessential television event, a media happening, a child of the age - and, eventually, a victim of it. There came a moment when Apollo 8 was midway between Earth and the Moon, and they pointed a television camera back at the Earth and beamed the images down. Pictures from later missions were clearer, better, more intrinsically interesting, but Apollo 8's were the first. There was our world, a whole planet visible in one glance. It was a poignant, slightly shocking image, a revelation of our ultimate human isolation and vulnerability.

Television demands drama or novelty or wonder or human interest - preferably all four. Apollo 8 provided elements of these; so did the Moon landing. Thereafter, space travel struggled to meet television's demands. Apollo 12 had trouble with the cameras. It ended up with the sort of ratings normally associated with late-night arts programmes. Apollo 13 blew up in mid-flight and, miraculously, limped back home. Even though there were no pictures from the capsule, the drama briefly restored public interest.

Subsequently, television made the Moon, and the experience of space travel, all too familiar. The very things that made space travel possible - reliable technology and the calmness of the astronauts - turned it into a televisual bore. We were left with bland jargon and modest insights. Beep] 'Boy, what a view]' Coverage was reduced to summaries on news bulletins. Curiosity fatigue was as real 20 years ago as it is now. Perhaps it started on the Moon.

The reasons for the end of the Apollo programme were complex, but the lack of popular will and interest was behind them all. Generations had dreamed of the Space Age. Nobody had dreamed of the numbing effect of the media, and so nobody found a way to preserve the dream.

The author wrote 'Seize the Moment' with Helen Sharman, published last year by Gollancz. He is presently completing a novel.