A team of three researchers, working at Boeing, has submitted a patent application for a laser-powered aircraft propulsion system. Although it does seem ambitious, given our current, quite limited, knowledge of nuclear fission and fusion, the company believes that this self-powered engine could one day be used to propel airplanes, spacecraft and even missiles.
At present, commercial aircraft, such as the Boeing 787 Dreamliner, are driven by turbofan engines, containing turbines and fans through which the incoming air is compressed and then ignited, with fuel, to generate the necessary thrust. The new laser-powered engine takes an entirely different approach to producing thrust. Here, the engine features a fusion chamber, of sorts, where a large number of powerful lasers are fired at a radioactive material.
The radioactive target is in the form of a hohlraum possessing a combination of the stable deuterium and the radioactive tritium, both isotopes of hydrogen. The firing of the laser beams results in nuclear fusion, in which the hydrogen atoms fuse together to form hydrogen or helium gas. The thrust is produced when these hot gases escape from the back of the engine, under extremely high pressure.
A key feature of the new engine is a specially-designed thruster device, which is lined, on the inside, with a fissile substance (such as Uranium-238). The coating undergoes nuclear fission, when hit by the neutrons produced during the earlier fusion reaction, thus generating tremendous heat. The resultant heat is collected by means of a coolant, and then used to run a turbine. The electricity, produced by the turbine, is later used to power the engine’s lasers, without the need for any extraneous energy.
The application, submitted back in 2012 by California-based James Herzberg, Frank Chandler and Robert Budica, was recently approved by the United States Patent and Trademark Office. While the idea is decidedly unrealistic, given the limitations of currently-available technologies, the laser-powered engine could one day take humans to the farthest edge of our solar system.
Image Credit: Patent Yogi