Researchers at the University of Plymouth (UP) have been awarded a $1.3 million grant from the U.S. Defense Advanced Research Projects Agency (DARPA) to advance nonfuel propulsion for space travel. UP’s Mike McCullough believes that light can be converted into thrust through the use of quantized inertia (QI). The QI theory predicts that objects can be pushed by differences in the intensity of so-called Unruh radiation in space, similar to the way in which a ship can be pushed toward a dock because there are more waves hitting it from the seaward side. The theory has already predicted galaxy rotation without dark matter, and if a system is accelerated enough — such as a spinning disc or light bouncing between mirrors — the Unruh waves it sees can be influenced by a shield. Therefore, if a damper is placed above the object, it should produce a new kind of upward thrust. “I believe QI could be a real game-changer for space science,” McCullough said. “I have always thought it could be used to convert light into thrust, but it also suggests ways to enhance that thrust. It is hugely exciting to now have the opportunity to test it.” The research is being funded through DARPA’s Nascent Light-Matter Interactions (NLM) program, which aims to improve the fundamental understanding of how to control the interaction of light and engineered materials. McCulloch will collaborate with experimental scientists from the Technische Universität Dresden in Germany and the University of Alcala in Spain. Over the first 18 months, the Plymouth team will seek to develop a fully predictive theoretical model of how matter interacts with light using the quantized inertia model, providing a new predictive tool for light-matter interactions. A series of experiments will then be conducted in Germany and Spain to test whether the thrust is specifically due to quantized inertia and whether it can be enhanced significantly. “Ultimately, what this could mean is you would need no propellant to launch a satellite,” McCulloch said. “But it would also mean you only need a source of electrical power — for example, solar power — to move any craft once it is in space. It has the potential to make interplanetary travel much easier and interstellar travel possible.”