Lost in space: the making of '2001'

This cannot have been music to the ears of Stanley Kubrick's studio, MGM, which had given him four years, a free rein, and a staggering budget of $10m to develop his interstellar epic. The original title, Journey to the Stars, had given them the impression that Stanley's film would be a rip-roaring space adventure, but when they finally got to see it, they were gripped by fear.

Who in God's name would go and see this thing, which leapt from a story of cavemen to futuristic space exploration and was laden down with mind-bending astrophysics? 2001 did find an audience, initially the potheads and pill-poppers of the late 1960s counterculture: one particularly enthusiastic hippie is said to have charged at the screen shouting "it's God!"

A wider audience who were ready to appreciate the film's astonishing technical achievements and tolerate its excessive length followed. It made its money back, and Kubrick moved on: it was only over time that the significance of 2001: A Space Odyssey would truly be felt.

I must admit it's not my favourite Kubrick film (that would be Paths of Glory), but it's probably his most important. Fifty years later, when so much has changed in terms of special effects and cinematography, its achievements seem all the more remarkable. There's a purity, a startling clarity, to the deep-space scenes that's unequalled by any of the films that copied it. Geoffrey Unsworth's cinematography is resplendent, and the detail in Kubrick's sumptuous 70mm compositions is astonishing.

What's most impressive, though, is Stanley's sheer ambition: who else would have conceived of a film that aimed to imagine not only man's conquest of space but also our relationship with the universe, light-speed travel, the time-space continuum and the possible nature of God? And if Kubrick's aims sometimes exceeded what was possible, the result was fascinating.

Stanley was interested in aliens. After finishing Dr Strangelove, he became obsessed by them, and started dreaming up ways in which he could cinematically leap into the future to depict man's first encounters with extraterrestrials. He began reading Arthur C Clarke, and decided the elusive British sci-fi writer might be his perfect collaborator.

What one wouldn't give to have been a fly on the wall at Trader Vic's restaurant in Manhattan, on April 22, 1964, when the two men first met. Clarke was perhaps the most celebrated science-fiction writer of his age, an inventor, undersea explorer, the "prophet of the space age". But the two men didn't seem like a natural fit. Kubrick had previously described Clarke as "a nut who lives in a tree in India or somewhere", while the writer was only too aware of Stanley's difficult reputation.

But they hit it off, thanks to their shared fascination for space. In Clarke's memoir, he recalled Kubrick telling him he wanted to "make a movie about man's relation to the rest of the universe - something that had never been attempted in the history of motion pictures". No pressure then, and a lot of hard work lay ahead.

After reading through Clarke's work, Kubrick chose a 1948 short story called The Sentinel, which described a monolithic beacon left behind on the Moon by aliens to warn them whenever bellicose mankind becomes sophisticated enough to start making war in space. The two men then began meeting daily in Kubrick's office in Central Park to work simultaneously on a movie script, and a standalone novel.

They read voraciously about astrophysics, the universe, philosophy and space travel. And when Stanley began drawing designs for the shoot, he wasn't satisfied with rockets and space stations that looked nice: he wanted them to be as scientifically credible as possible. Arthur C Clarke's contacts came in handy: he introduced Kubrick to Harry Lange, who had worked with Wernher von Braun at NASA on spacecraft design. The resulting models were described by special-effects supervisor Douglas Trumbull as "probably the most precisely detailed ever constructed for a film".

The astronomer Carl Sagan was also consulted, on how best to depict extraterrestrial life, which must have been an interesting conversation, and as work on the screenplay dragged on for over two years, MGM began to get nervous. Things got worse when Stanley started shooting, and an original budget of $5m was eaten up by model-making, and monster sets at Shepperton Studios in England.

Shooting began in December of 1965, and lasted two years, as the director pushed himself and everyone tirelessly towards the holy grail of authenticity. A huge sticking point was the central plot device of HAL 9000, the Discovery spaceship's onboard computer which has a kind of nervous breakdown at a crucial moment. IBM executives were consulted about how HAL might best be rendered, and were helpful until one of them realised that 'HAL' was three letters away from 'IBM'. Was somebody having a laugh? Clarke always insisted this was a coincidence, but it seems unlikely.

Music, costumes, spacecraft, sets, the accurate depiction of zero gravity - every single aspect of the film was gone over with a fine tooth-comb. Kubrick combined classical pieces like 'The Blue Danube' and 'Thus Spake Zarathustra' with images of rocket ships gliding through deep space to create something jaw-droppingly beautiful. And the film's storytelling audacity was just as impressive. 2001 opened on a bleak pre-historic African plain, where a group of Neanderthals face extinction as they're constantly driven away from a watering hole by a rival tribe. Then they find that giant, faceless alien monolith, which in some mysterious way inspires one of them to use a jawbone as a weapon. When they defeat their rivals in bloody combat, an alpha male throws the bone triumphantly into the air, where a famous jump cut catapults the viewer millions of years into the future, as a similarly shaped satellite orbits the Earth.

The apes' descendants have prospered, and a daring mission is en route to Jupiter to investigate its potential when something goes awry. HAL will end up turning on his human masters, one of whom will be flung through the universe in a terrifying accelerated ride.

Expecting Flash Gordon, MGM executives were baffled by the 161-minute, largely wordless epic that was screened for them in the spring of 1968. Nothing like it had ever been seen before, and they must have wondered how they were going to market it. Frantic studio spinning came up with posters promising "an epic drama of adventure and exploration", and the slightly trimmed behemoth was ushered into American cinemas with low expectations in early April 1968. It was a huge risk for Kubrick, whose reputation as a director who combined bold, original cinema with strong box office returns would have been destroyed had it failed, ruining the creative autonomy he'd won by moving to England.

As we've mentioned, lots of critics initially hated it, and accused Kubrick of monomania, and pretension. But 2001 had the great good fortune to arrive in the late 1960s, a time of great experimentation and social upheaval: its dreamy visuals and woolly philosophising were embraced by a generation keen to become everything their parents were not. It was subsumed by the zeitgeist, and catchphrases like HAL's chilling "I'm sorry, I can't do that Dave" entered the popular lexicon.

Its reputation would only grow over time, and 2001 inspired the makers of everything from Star Wars and Blade Runner to Alien and Solaris. Meanwhile, Stanley regrouped, and moved on to his next project, A Clockwork Orange, which would cause him even more trouble.