Nulcear Pulse Propulsion

Probably the most interesting form of nuclear propulsion is pulse propulsion. This propulsion system was conceptualized in the 1940s by Freeman Dyson during the Manhattan Project. Dyson’s idea, called the Orion project, was to generate thrust by igniting a small series of nuclear bombs, followed by a pusher plate absorbing the energy and converting it into thrust. 

The Orion ship would need around 800 bombs about the size of a small compact car, exploding beneath the ship at a rate of about one every second, to push it into orbit. Although this may seem excessive, this is actually far more efficient than chemical rockets. In fact, in order to match the theoretical capabilities of the Orion project rocket using a conventional chemical rocket, it would be as tall as the Empire State Building. Also, a nuclear pulse propulsion rocket could, hypothetically, reach speeds three times higher than chemical rockets. For a manned crew, maximizing speed is crucial because it will minimize astronauts' exposure to cosmic radiation and microgravity. 

Although this design does seem great on paper, there are some massive drawbacks. The truth is that we do not have the technology to control the nuclear fallout of hundreds of nuclear bombs on Earth’s atmosphere. There are also challenges with the spacecraft handling the mechanical stress from nuclear detonations. Aside from engineering obstacles, in 1963 there was a Limited Ban Treaty that prohibited nuclear explosion in the atmosphere, underwater, and in outer space, ruling out the possibility of a nuclear pulse propulsion rocket in the near future.

While the challenges of nuclear pulse propulsion such as controlling fallout, managing mechanical stress, and negotiating international treaties may seem daunting, there are not unconquerable. We hope to fuel the initial period of nuclear propulsion for our future generations to discover ambitious solutions, unleashing the full potential of nuclear pulse propulsion.

Here is a short video on an imagery launch of a nuclear pulse rocket. The booster phase is chemical propulsion and once in orbit it converts to the nuclear pulse propulsion.