The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

endeavor. The problem was that because Orion was
classified, few people in the scientific and engineering
community even knew it existed. Nance (now managing
the project) therefore lobbied the Air Force to
declassify at least the broad outline of the work. Eventually
it agreed, and Nance published a brief description
of the first-generation Saturn-launched vehicle in
October 1964. The Air Force, however, also indicated
that it would be unwilling to continue its support
unless NASA also contributed significant funds.
Cash-strapped by the demands of Apollo, NASA
announced publicly in January 1965 that no money
would be forthcoming. The Air Force then announced
the termination of all funding, and Orion quietly
died. Some $11 million had been spent over nearly
seven years.
Overshadowed by the Moon race, Orion was forgotten
by almost everybody except Dyson and Taylor.
84 Dyson reflected that “this is the first time in
modern history that a major expansion of human
technology has been suppressed for political reasons.”
In 1968 he wrote a paper 85 about nuclear pulse drives
and even large starships that might be propelled in
this way. But ultimately, the radiation hazard associated
with the early ground-launch idea led him to
become disillusioned with the idea. Even so, he
argued that the most extensive flight program envisaged
by Taylor and himself would have added no
more than 1% to the atmospheric contamination
then (c. 1960) being created by the weapons-testing of
the major powers. A detailed account of the scheme is
presented by Freeman Dyson’s son, George, in his
book Project Orion, published by Henry Holt in 2002.
Being based on fission fuel, the Orion concept is
inherently “dirty” and probably no longer socially
acceptable even if used only well away from planetary
environments. A much better basis for a nuclear-pulse
rocket is nuclear fusion—a possibility first explored in
detail by the British Interplanetary Society in the
Daedalus project.
Orion, Project An artist’s rendering of an interplanetary spacecraft propelled by pulsed nuclear fission.
NASA
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