An engineer who works for NASA has put forward a proposal for a new way to travel through interstellar space—a "helical engine" that could, potentially, push a spacecraft forward without the need for any propellant at all.
David Burns, from NASA's Marshall Space Flight Center, presented his idea on the space agency's Technical Reports Server, which provides access to documents relating to aerospace that were created or funded by NASA, including meetings, journal papers, reports, and patents. Burns' research, which he funded himself, is described as an "attempt to define an in-space propulsion engine that does not expend propellant."
He says he is aware of the pitfalls of the work, saying the idea is a thought experiment and even the "basic concept is unproven." However, speaking to New Scientist—which first reported on his work—Burns said he is prepared for any and all criticism. "If someone says it doesn't work, I'll be the first to say it was worth a shot," he told the magazine. "You have to be prepared to be embarrassed. It is very difficult to invent something that is new under the sun and actually works."