I'm old enough (just) to remember the sheer excitement of the later Apollo missions. I remember the buzz that went round my school when Viking landed on Mars, and the first pictures of marmalade rocks and tangerine skies were beamed back. But nowadays the space race is ancient history. Pundits in the TV studios of the 1960s confidently predicted hotels on the moon by 2000, interplanetary trade by 2020. This has not, to state the obvious, come to pass. Re-watching the film Apollo 13 recently brought home a terrible truth: 'going to the moon', which generations of eager SF fans looked forward to is no longer something in mankind's future. Travelling to the planets is not something we do, and almost certainly won't be something our descendants will do. Instead, it is something our ancestors did, like building pyramids or hand gilding editions of the Bible. Apollo 13 works brilliantly at evoking the Saturn V launch and the weightlessness of the astronauts; it works just as well evoking the cultural milieu of the early 1970s. But we live in a new century now. Heroic space explorers will not walk on other worlds. The most we can hope for now is that a computer chip the size of a Sugar Puff fitted to an thirty-kilo nuclear motor will have the glory of clapping its silicon eyes on the outer planets. It is simply not the same.

I'm very far from being alone among SF authors in lamenting this state of affairs. Steven Baxter, to drop one name, has a near-obsession with the glories of the old space race. His novel Titan (1998) even resurrects the last great Saturn V from its lying-in-state at Cape Canavaral, scrapes off the rust and sends it booming into space again. He applied for (and was turned down for) the space programme. But I can't imagine there is a hard SF author in the West who doesn't share Baxter's obsession to some degree. Personally, I'd happily sell my granny to realise the dream - assuming I could find a senior-enough member of NASA prepared to take the old lovely in part exchange for a place on the next shuttle launch.

The big question we have to answer is - what happened? Why did the space race, which we confidently thought was a London Marathon, turn into a 100-metres dash, and then into a miniaturised slo-mo Robot Wars? Who is to blame?

Do you want to know the terrible truth? We are. SF authors and SF fans are. It is the very success and popularity of science fiction itself that finished off the space race. There was once a space shuttle called Enterprise which spent most of its life sitting on the platform waiting for the clouds to thin out sufficiently to allow a launch, and a goodly portion of that time being wheeled back into its mega-garage because a light drizzle had started up. It looked like an overfed aeroplane, with Homer Simpson curves and stubby little chicken-wings. It was crewed by a few decent, dull, smiling professionals. It flew up a few miles, circled round, and flew back down again. Then there was another space-craft called Enterprise crewed by an ethnically diverse mix of charismatic, sexy, passionately-overacting humans. This Enterprise flew near-instantly to all the most exciting corners of the galaxy, got into edge-of-the-seat dramas, zoomed into and out of danger. It looked - madly, but somehow rightly - like a white Frisbee with spreadeagled legs, weirdly insect-like and techno, plausible and yet out-of-this-world. Which last thing is, when you think about it, exactly what you want a spaceship to be.

Which would you rather watch? Be honest. SF is too good at what it does. Why should people bother with real space flight when fictional space flight is so much better - better in every way, more exciting, more engaging, more satisfying (and you get a better view)? The idea of travelling to the stars is something that touches the souls of most human beings, but why should they invest emotionally and intellectually - and therefore financially - in actual space technology when they can get so much more from fictionalised space flight? It goes even further than this: SF has been so convincing that many people now assume we can zap from planet to planet, from star to star - hence the X-Files-ish culture that just knows Roswell is full of futuristic spaceships operated by the US government. And what do these spaceships look like? Not like gone-to-seed 747s with withered wings sitting on their tails, that's for sure. No - like the Millennium Falcon. Like the fighters from Independence Day (woo-hoo!). If all the money invested in SF films over the last thirty years had been given to NASA, we'd have a moon base and a Mars base by now. But which would you rather? A photo of a smiling, bland-faced ex USAF pilot standing in a flabby white suit on Mars? Or Stars Wars, Alien, Terminator and all the rest?

I have another memory of the real space race, one shared by millions. I remember exactly where I was when Challenger blew up. Something important is crystallised by the contradictory emotions experienced by those watching that terrible disaster. On the one hand, it was something appalling and tragic, something that moved many people to tears as it happened. But on another level, the live TV pictures bumped people from one mode of watching to another, and gave a guilty undertow to the emotions - the Challenger launch was certainly the most memorable and in a terrible way the most exciting of all the shuttle launches. This is the case precisely because shuttle launches, as I've been saying, are renowned for being dull, for being always delayed and postponed, and then for providing us, when they finally happen, with a dull repetition of all the other dull launches. What the Challenger disaster did was suddenly, momently, shift modes: from the 'real' mode of an actual launch, to the 'SFX' mode of a film. In SF films, spaceships explode all the time, and it is exciting. When the Challenger exploded, the moment collapsed together our perceptions. That was one reason why, apart from being so terrible, it was so unsettling. Ever since that moment, culture has striven to separate SF from space travel, to emphasise the dullness and routine-ness of the former in a way that turns people thoroughly off the reality. At the same time the culture industry churns out brilliantly-realised images of space travel that people turn on to in increasing numbers. These pathways continue to diverge, and that is the death-knell for real space travel, because if people don't want it then politicians won't spend money providing it. The future isn't real; it is better-looking than that.

I have seen the future and it doesn't work; it produces glittering images of pretend-working instead. We are to blame!