[Illustration: 57. The Project Orion test vehicle was used to
explore the feasibility of a unique type of propulsion which
utilized successive nuclear explosions behind the rear pusher
plate.]
Project Orion was an attempt to solve the problems of propulsion for
long-term manned journeys to other planets by creating an engine that
would use successive nuclear explosions to propel very large space
vehicles. The Orion spacecraft was designed to carry many small nuclear
explosive systems which would be ejected sequentially from the rear of
the vehicle. These units would explode some distance behind the
spacecraft. The expanding debris, in the form of high-velocity,
high-density plasma, would strike a pusher plate at the rear of the
Orion vehicle.
Work on Project Orion was halted in 1963 when the Limited Nuclear Test
Ban Treaty, which prohibited atmospheric tests of the propulsion system,
was signed.
The Project Orion Test Vehicle—on display—demonstrated the basic
principle of intermittent thrust from explosive charges. Test data
provided by this model would have assisted engineers in developing the
full-scale spacecraft.
The test vehicle carried five high-explosive plastic charges which were
ejected from the rear of the craft. Compressed nitrogen powered the
ejection system. Each charge was attached to the vehicle by a .9-meter
(3-foot) cord. A microswitch exploded the individual packages. The
Project Orion Test Vehicle was first flown successfully in October 1959.
From the Gulf Energy and Environmental Systems, Inc.