This week's curious story will continue last week's theme of space exploration. This time, we will take a look at one of the less outrageous projects of one of the 20th century's greatest space travel visionaries.
Part II: Nuclear propulsion
Dyson - At the center of this story stands arguably one of the greatest scientists and inventors of the 20th century - Freeman Dyson. Although his name to many is synonymous with over-engineered fans, blow dryers, and vacuum cleaners*, Dyson's work had such breadth that it should be equally familiar to students of quantum field theory as well as science fiction enthusiasts (think Dyson sphere and Dyson tree**). This format could be filled with Dyson-related stories but today we will focus on just one of them; Project Orion.
Freeman Dyson in 2007
Project Orion - To fully appreciate the seriousness of this work, we have to mentally go back to the late 1950's and early 1960's - a time when nuclear energy promised to revolutionize every aspect of life and when flying cars seemed only a mere one or two decades away. It was at this time, that Dyson worked on a nuclear-bomb-powered space rocket; the Orion propulsion system. The idea was simply to ride the blast waves of successive nuclear bombs which should be ejected in rapid succession from the back-end of a rocket akin to a giant infernal vending machine.*** Dyson himself described the people working on the project as "a bit mad" but there were also some very practical advantages this this system, chiefly the ability to reach speeds well beyond that of chemical rockets (up to 300km/s against the 15km/s of Voyager 2). General Atomic, the private-sector developer of the project, even managed to complete successful non-nuclear prototype of this new rocket. However, in a somewhat ironic twist of fate, Dyson himself lobbied for a ban of all atmospheric and outer space nuclear testing (the 1963 test ban treaty) which ultimately ended the project.
Artist's conception of the Project Orion "basic" spacecraft, powered by nuclear pulse propulsion
Interestingly, the idea behind Project Orion never quite died: in the 1980s a similar concept resurfaced as Project Longshot and in the early 2000s, NASA paid Freeman Dyson's son (George Dyson) for a copy of 1800 pages related to the original Orion project to preserve some of the know-how.****
For this Monday morning I leave you with a quote from Douglas Adams' "Hitchhiker's Guide to the Galaxy":
“The ships hung in the sky in much the same way that bricks don't.”
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*Built by a company founded by James Dyson and not related to our protagonist
**A Dyson sphere describes a structure encapsulating an entire star to capture a large percentage of its energy. A Dyson tree is a hypothetical genetically engineered plant capable of growing inside a comet to provide a human habitat
***Like many big ideas, science was just catching up with science fiction, specifically the 1940 short story "Blowups Happen" in which the author Robert Heinlein mentions powering spaceships with nuclear bombs 5 years before the first ever exploded
****Here is a short TED talk given by George Dyson with a lot of photographs (Link)
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