The Project Orion still has iconic status in the eyes of many to this day, and i will not conceal the fact that the notion really had fascinated me when i first read of it in a newspaper years ago in a passing reference in a much bigger article on the space age. My eyes lit up and i started imagining how space travel could change (or rather could have!). ;)
Though i was planning to continue to write on Swarm Intelligence based routing for some more articles and then was thinking of going to dynamic programming and speech recognition. I decided that i would write on the Orion first. I hope to dedicate the next three or four posts only on this milestone project!
The video below is an excellent BBC excerpt from “To Mars by A-Bomb” (2003) showing some footage of the tests during the Orion years with some commentary from Freeman Dyson (who also happens to be a man i greatly venerate and is one of my heroes!) and Arthur C Clark. This is a rather short video! Do have a look!
I would give a short introduction to those who are not familiar with Orion.
We are used to space-ships using conventional fuels. For rating the efficiency of such fuels one parameter is Specific Impulse. It is stated in seconds and it indicates how many kilograms of thrust are obtained by the consumption of one Kg of the propellant in one second. This value is more or less characteristic of the type of propellant used, however there can be variations due to operating conditions and engine design. Therefore the higher the specific impulse the lesser the propellant is needed to gain a given amount of thrust.
Stanislaw Ulam in 1947 proposed Rocket propulsion using nuclear explosions, or pulsed nuclear explosions. He realized that nuclear explosions had not yet been contained in a combustion chamber. So instead it was proposed that the Orion design would work by dropping fissionable explosives out of the rear of the vehicle and catching the blast with a thick metal pusher plate.
The key components of the Orion are as in the figure.
Photo Courtesy: NASA Archives
The project initiated in 1958 under Ted Taylor and Freeman Dyson. This was the first such think tank assembled since the Manhattan Project. Orion offered both very high thrust and very high specific impulse. The potential it offered was enormous, Freeman Dyson has been quoted as saying that a single mission could provide with a permanent moon base and that it was possible to fly to and return back from Pluto in under one year. The orion could touch speeds upto 0.1 c according to some estimates and could carry as large as 8 million tons of mass, which could be as big as a city!!
The project died, due to concerns with the fallout due to each launch. Though Dyson maintained that conventional explosives could be used for launching the Ship out of Earth’s atmosphere and then nuclear fuel would take over. The Partial Test Ban Treaty of 1963 is said to have killed the project.
Even though the project died it was significant for its time in terms of stimulating possible engineering concepts.
Related Posts on this Blog: