Originally Published Through Yahoo Voices
Nuclear Pulse Propulsion Revisited
Stanislaw Ulam had the idea back in 1947. Use nuclear bombs; very small ones, but hundreds or thousands of them, to push a large spacecraft into orbit.
Ted Taylor formed a team in 1958 which included Physicist Freeman Dyson to develop and produce a working model of what would become Project Orion.
In 1963, with the signing of the Partial Test Ban Treaty, Orion was grounded before it ever flew.
Now, in 2010, with the Space Shuttle program nearly grounded, and no viable solution ready to take it’s place for years to come, is the time to reinvent Project Orion.
The basic concept of an Orion spacecraft is in effect a multi-storied ‘pogo stick’. Instead of a small jumper at the end, there would be a large flat disk which is connected to the main body by a series of shock absorbers and pneumatic spring systems. Through the center of that disk a tactical nuclear shaped charge would be deployed that would detonate no more than 90 feet from the plate. This nuclear explosive, with a yield of about 150 tons of TNT would be a shaped charge, with an explosion in the shape of a cigar, pushing the long end and massive blast effect against the plate. The plate would compress against the shocks, then rebound in time to absorb the next explosion.
Although it would seem that being less than 100 feet from a nuclear explosion would destroy everything, in both theory and practice during the many nuclear tests that were going on in the 1950’s – it was proven that although the plate would be exposed to thousands of nuclear explosions during it’s lifetime, it would not be significantly damaged, and would not even become very radioactive.
A shaped nuclear charge of the type developed for Orion would produce very little radiation, almost no EMP(electromagnetic Pulse) and very little fallout to be left behind. Each bomb was planned to be about the diameter(6 inch) of a #10 tin can, although each device would weigh in at close to 300 lbs. These devices would be specifically made to produce energy in the form of x-rays and high density plasma, not radioactive fallout or a massive gamma ray burst like in normal nuclear weapons.
Launch of Orion was originally planned to the from the aptly named Jackass Flats, in Nevada. A ground launch triggered by the detonation of any form of nuclear explosion is a bad idea, so other ideas were considered, including using rocket boosters to bring the ship to a decent altitude, then trigger the bomb blast and lift onwards, flying the ship to a sub-orbital altitude, using the ship only outside of the main orbital sphere, and also a sea launch.
Based on the information known at the time, the amount of radiation released from a ground to orbit launch of the test Orion would be equal to the same radiation vented by a single 10 Megaton atmospheric detonation. Orion would also have a very reduced EMP pulse due to the very small size of the individual nuclear weapons so as long as the launch zone was more than 100 miles from major population centers, no effect would be felt by the electromagnetic surge.
The reference model of Orion would have been about 4,000 tons, about 20% heavier than the entire Saturn V moon rocket. It would stand 180 ft or about 18 stories, and be a cylinder with a diameter of about 120 ft. About the size of a small office building. It would carry at least 800 of these tiny tactical nuclear shaped bombs, each the size of a #10 tin can, packed with nuclear material and designed to explode in a shaped blast to push the ship to ever faster speed. Unlike the Saturn V rocket, the payload to LEO (300 mile orbit) for Orion was about 1,600 tons. The Saturn V could only bring 130 tons to orbit. An Orion to the Moon would be able to drop 1,200 tons, compared to a maximum of 52 tons capable with the Saturn V era.
A single Orion would be able to not only put a permanent Moon base into operation but could also have put the entire International Space Station into orbit for assembly with 1 flight! NASA has taken more than 12 years, and 25 shuttle flights to build the station in a piecemeal fashion. Now, the Space Shuttle program is ending, and the Station is still not fully complete.
Even with the ethical problems of nuclear explosions going off in the atmosphere, we expend more damaging automobile exhaust in a day than a single Orion launch would do. An Orion launch would not significantly effect the planet as a whole, and if some of the more updated proposals were taken into account, would have about the same impact as a normal shuttle launch, with more than 10x the carrying and cargo capacity.
A modern Orion proposal would include the use of Space Shuttle Solid Boosters to lift the vessel to a launch height of around 90,000 feet where the first nuclear device would detonate. Because of the remoteness of the launch area, the explosion would do no real damage, and the majority of the radioactive fallout would dissipate in the rarifed upper atmosphere. As the ship accelerated and passed through the magnetosphere, it could also deploy small tethers, strips of aluminized foil tens of meters long that would attract the radioactive particles and allow them to deorbit unto the Van Allen belts so they would be rendered harmless.
With the computer power available today and the high explosives also available, full scale test models could be built and test flown to both prove the concept and iron out any potential design flaws. For the cost of one Space Shuttle launch, an Orion test vehicle could be built and flown using conventional explosives instead of nuclear. It would not be able to achieve orbit, but could certainly prove beyond any shadow of a doubt that this brute-force method should and does work properly.
With the retirement of the Space Shuttle imminent, alternatives need to be developed. Orion is one such alternative that would not only reduce the Nuclear stockpile in an appropriate manner, but it can also reduce nuclear waste, as the ballast for the bombs could conceivably be depleted uranium or other dead loss radioactive material. It certainly deserves a second look.