Let's hope this thing never actually comes into being.
The Ultimate 1950s Space Technology, which almost made it to Saturn
Obviously, "almost" is a key word here, but apparently NASA still has "small secret contingency plan division" which is dedicated to preserving
"Orion" nuclear propulsion technology - and reviving it in case of a killer asteroid threat.
So what exactly is this "Project Orion" - the most radical propulsion technology for kick-ass space missions? No, it's not the NASA's future space
capsule ("Apollo-on-steroids", some may say) - but a proposed colossal nuclear-bomb-powered rocket from 1958:
With a mass of 1000-2000 metric tons and 1000 nuclear bombs for propulsion the medium version alone would have been a terrifying monster. The
"super" Orion design at 8 million tons could easily be the size of a small city. Here is a size comparison of some of the proposed versions:
Various mission profiles for "Orion" were considered, including an ambitious interstellar version (asteroid defense and mining were among other
ideas). This called for a 40-million-ton spacecraft to be powered by the sequential release of ten million bombs, each designed to explode roughly 60
m to the vehicle's rear.
The Partial Test Ban Treaty of 1963 effectively killed the project, after $11 million had been spent on its development over nearly seven years. These
are the screenshots from top secret video, showing the tests:
Classified... declassified... and RE-classified!
Parts of this project still seem to be classified today. George Dyson recollects: "NASA had no interest, they tried to kill the project. The people
who supported it were the Air Force, so they made it top secret..." It is still very dangerous and touchy subject, mostly because of the heart of the
project - controlled ways to get directed energy explosions, and directing nuclear explosions at the ship.
Project Orion (nuclear propulsion)
Project Orion was the first engineering design study of a spacecraft powered by nuclear pulse propulsion, an idea proposed first by Stanisław Ulam
during 1947. The project, initiated in 1958, envisioned the explosion of atomic bombs behind the craft and was led by Ted Taylor at General Atomics
and physicist Freeman Dyson, who at Taylor's request took a year away from the Institute for Advanced Study in Princeton to work on the project.
By using energetic nuclear power, the Orion concept offered high thrust and high specific impulse (10 to 1,000 km/s) at the same time; the optimum
combination for spacecraft propulsion. As a qualitative comparison, traditional chemical rockets (the Moon-class Saturn V or the Space Shuttle being
prime examples) provide (rather) high thrust, but low specific impulse, whereas ion engines do the opposite. Orion would have offered performance
greater than the most advanced conventional or nuclear rocket engines now being studied. Cheap interplanetary travel was the goal of the Orion
Project. Its supporters felt that it had potential for space travel, but it lost political approval over concerns with fallout from its propulsion.
The Partial Test Ban Treaty of 1963 is generally acknowledged to have ended the project.
In the 1954 Operation Castle nuclear test series at Bikini Atoll, a crucial experiment by Lew Allen proved that nuclear explosives could be used for
propulsion. Two graphite-covered steel spheres were suspended near the test article for the Castle Bravo shot. After the explosion, they were found
intact some distance away, proving that engineered structures could survive a nuclear fireball
The biggest design above is the "super" Orion design; at 8 million tons, it could easily be a city. In interviews, the designers contemplated the
large ship as a possible interstellar ark. This extreme design could be built with materials and techniques that could be obtained in 1958 or were
anticipated to be available shortly after. The practical upper limit is likely to be higher with modern materials.
Most of the three tons of each of the "super" Orion's propulsion units would be inert material such as polyethylene, or boron salts, used to
transmit the force of the propulsion unit's detonation to the Orion's pusher plate, and absorb neutrons to minimize fallout. One design proposed by
Freeman Dyson for the "Super Orion" called for the pusher plate to be composed primarily of uranium or a transuranic element so that upon reaching a
nearby star system the plate could be converted to nuclear fuel.
George Dyson about the development and the current state of Project Orion:
[edit on 16-4-2010 by acrux]