Boeing has patented a laser powered propulsion system for airplanes. A number of sites reported on the patent, with eye-rubbing headlines that told the story. BusinessInsider headline read, "Boeing just patented a jet engine powered by lasers and nuclear explosions." Benjamin Zhang said the US Patent and Trademark Office approved Boeing's application for a laser and nuclear-driven airplane engine.
Zhang noted that presently the Boeing Dreamliner is powered by multiple turbofan engines with their fans and turbines in place to compress air and ignite fuel to provide thrust. The engine presented in Boeing's patent application takes another route. Zhang said the laser engine may also be used to power rockets, missiles, and spacecraft.
The new engine would work "by firing high-power lasers at radioactive material, such as deuterium and tritium," said BusinessInsider. "The lasers vaporize the radioactive material and cause a fusion reaction—in effect a small thermonuclear explosion," said the article. "Hydrogen or helium are the exhaust byproducts, which exit the back of the engine under high pressure. Thrust is produced."
In this approach the inside wall of the engine's thruster chamber coated in uranium 238 reacts with the neutrons from the nuclear reaction and generates immense heat. "The engine harnesses the heat by running coolant along the other side of the uranium-coated combustion chamber," said Zhang. "This heat-energized coolant is sent through a turbine and generator that produces electricity to power the engine's lasers."
Three inventors named in the patent application are Robert Budica, James Herzberg and Frank Chandler of California. The applicant is listed as The Boeing Company in Chicago. The patent was filed in 2012.
(Score: 2) by turgid on Monday July 13 2015, @07:58PM
What a goat. I originally read this story on my phone and the text was so small I didn't notice the link to the phys.org story, just the Business Insider one. Yes, they're expecting fission from the 238U. I suppose fission fragments are the way to go. Not sure about the fusion part. If it's insignificant in terms of thrust, maybe there could be a cheaper and simpler source of neutrons? Tritium isn't cheap, it's difficult to handle and has a short half-life.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].
(Score: 2) by gnuman on Tuesday July 14 2015, @04:12AM
Yes, they're expecting fission from the 238U.
Which means it is dead concept for terrestrial engines. It is also a dead concept when it comes to rocketry considering other, more exotic means,
https://en.wikipedia.org/wiki/Spacecraft_propulsion#Table_of_methods [wikipedia.org]