'We'll make Saturn by '70'

In the late 1950s, Freeman Dyson worked on a project to turn weapons of mass destruction into an intergalactic fuel source. Helen Hague reports.

When the young George Dyson told school pals in California that his dad would be going into space, it was not just a groundless playground boast. Freeman Dyson, the renowned English theoretical physicist, had joined a group of scientists picked to work on a government-sponsored attempt to build a 4,000-ton manned spaceship propelled by small nuclear bombs.

This was Project Orion, launched in the summer of 1957 in the midst of the cold war and the space race. The Russians had just sent Sputnik into space and the atom was fast colonising America's imagination. All things seemed possible - from cheap fuel to space probes. And all things space age were hot in fashion, design and consumer durables. Even automobiles had space-rocket style tail-fins.

It was not just wide-eyed schoolboys who believed space travel was imminent. A good few of the Project Orion scientists, working at civilian contractor General Atomic's launch-pad-shaped headquarters, were keen to get out there and explore. Dyson told his son he hoped to be among them. Fired up for innovation, the young team's slogan became "Saturn by 1970".

When the US authorities issued a brief press release on the project, in July 1958, Dyson drafted a "A Space Traveller's Manifesto". This is just one of the many gripping snippets of source material contained in his son's chronicle of this extraordinary episode in the space race. But by 1965, the US government had abandoned the project. It is the story of a team fuelled by optimism, hope and a determination to open up new frontiers, pieced together by the man who, as a boy, was convinced a spaceship was being readied for launch inside General Atomic's futuristic HQ.

"We have," Freeman wrote in his manifesto, "for the first time, imagined a way to use the huge stockpile of our bombs for a better purpose than murdering people. Our purpose, and our belief, is that the bombs that killed and maimed at Hiroshima and Nagasaki shall one day open the skies to man."

Even before the nuclear-test ban, when 100 megatons of waste were being dispersed into the atmosphere each year, the nuclear fallout bomb-powered spaceships would generate was seen as environmentally untenable. "We assumed there would be cleaner bombs to make it acceptable," Freeman says. "But that never happened."

The Project Orion team, including many talented foreign nationals with the requisite security clearance, focused on designing a simple, rugged spaceship capable of carrying large payloads cheaply all over the solar system. For long-range space exploration, nuclear fission - detonating a series of small bombs to propel the vehicle - certainly had the edge on chemical rockets. In the end, chemicals won out, leading to the Apollo landing on the Moon a decade later. But their scope remains limited. "We always said chemicals would get you to the Moon but no further. That was our main sales pitch," Freeman says.

Brian Dunne, the project's leading experimentalist, reflects after more than 40 years: "We had a wonderfully free time before any of the fallout stuff came down. It was a crazy era. All our values were tweaked because of the cold war. It was a closed society and all kinds of strange ideas were able to grow" - including designs based on bottling equipment at a Coca-Cola factory for shunting bombs along in a regular sequence ready for detonation.

In June 1959, a US air force briefing revealed "some possible military uses of the Orion vehicle" - including launch platforms for deep space weapons. This was the nether underbelly of linking up with the military to explore space in the midst of the cold war. However, Nasa was not that interested. Ted Taylor, in charge of the project, confided in his personal journal:

"Had vile thoughts in the evening about how to use antimatter for wiping out populations. Perhaps someone should write a book called 101 Ways to Eliminate the Human Race and call it quits." His fears were later fuelled by a two-year stint at the Pentagon in the mid-1960s. What he found left him with a new ambition: to "stimulate the complete abolition of nuclear bombs".

Freeman and George agree that excessive government secrecy is hampering international cooperation in scientific projects. George was able to piece together the Orion story more "because of the benevolence of individuals than of institutions". He was appalled by how the doors of officialdom kept slamming shut. But the proliferation of secrecy has not stopped the proliferation of bombs. And nuclear stockpiles have grown apace.

The bulk of Project Orion's research should, they argue, be declassified, with potentially threatening data stripped out. The pair also acknowledges that for many bright young scientists, the cutting edge has shifted from space to biology. Freeman believes there is a link. Biotechnology offers hope of providing food for humans on other planets. "If you really want to settle on Mars, you'd better breed some kind of potato you can grow."

George agrees. "Survival in space or on planets is more a problem of biology than engineering." In time, both believe, exploring the planets and even space tourism will become a reality. The Dysons have not seen that much of each other over the years and appear to be relishing the novelty of time spent together promoting the book. In the late 1970s, they themselves were the story. In The Starship and the Canoe , Kenneth Brower charted how Freeman searched for meaning in the stars while George, who designed a giant canoe to explore the icy wilderness of northeast America, sought it in the sea below. George dropped out of highschool, built himself a tree house 30m up a Douglas fir in the temperate rainforest near Vancouver and lived there for three years. He went on to write about boat-building and the Aleutian people in Baidarka. Four years ago, his Darwin Among the Machines - on emerging information networks - was published to widespread critical acclaim.

As Freeman's son, George was initially reluctant to write the Orion story. He even tried to get writers he admired to pitch the idea, before setting out to write the story he thinks should be told while many of the players are still around. He also believes that Project Orion could be dusted down for future interplanetary missions or if an asteroid or comet came hurtling towards the Earth. Reviving it would take a complete change in the perception of risk. But he adds: "There could maybe be an Orion ship under international control that could wait out in deep space to be called upon. It could very quickly get out there and give something a little nudge." Two recent Hollywood blockbusters - Deep Impact and Armageddon - explored such doomsday scenarios, none too well, according to George.

A few months after sending Nasa 1,759 pages of the documents he had uncovered, George received a draft report, External Pulsed Plasma Propulsion and its Potential for the Near Future . Is there something Nasa has not told us?

Project Orion : The Atomic Spaceship 1957-1965 by George Dyson is published by Allen Lane, £12.99.