The idea of using nuclear bombs to propel a space craft was first proposed
by Stanislaw Ulam at Los Alamos in 1955. In 1958 Los
Alamos’s Ted Taylor and Dr. Freeman Dyson, then a theoretical
physicist then at the Institute for Advanced Study at Princeton,
began the serious work on an Orion propulsion system at General Atomics, a
company founded to explore the peaceful applications of nuclear power. Funding
was provided by ARPA (Advanced Research Projects Agency.) The team led by Taylor
and Dyson refined the Orion concept, packing the bombs with polyethylene to
provide a focused plasma to enhance the propulsion speed. They also developed a
method of “greasing” the pushing plate to inhibit it’s erosion by the heat of
the bomb explosions. The General Atomics team launched a series of test
articles, propelled by conventional explosions, the last in November of 1959 at
a height of a hundred meters.
The Orion ship conceived at this time would have been immense. It would have
been in the shape of a bullet, six stories high, weighing ten thousand tons,
most of which would have gone into Earth orbit. At a time when the Mercury
program was planning to launch a single astronaut in cramped conditions, this
version of Orion would have had a crew of a about a hundred and fifty in roomy
conditions. Orion would have been like a space going battleship, with no need
of the weight saving methods necessary for conventional space craft. Perhaps
half seriously, Dr. Dyson said that the motto of the Orion team was, “Mars by
1965, Saturn by 1970.”
The promise of Orion began to fall apart by the end of 1959. The new space
agency, NASA, got all of the civilian space projects and the Air Force got the
military ones. ARPA was left with Orion as a kind of orphan program. It was
later transferred to the Air Force, but the Air Force could never find a need
for a space going battleship. At this point, the idea of a “first generation”
Orion, to be launched into low Earth orbit by a Saturn V rocket, and only then
to use its nuclear bomb drive to send eight astronauts to Mars, was explored.
But the Nuclear Test Ban Treaty, which forbade the test explosions of nuclear
bombs in the atmosphere or space, put the final nail into Orion’s coffin. The
project was terminated in 1965.