United States, Jan. 14 -- GE Aerospace and Lockheed Martin completed a series of engine tests demonstrating the viability of a liquid-fueled rotating detonation ramjet for use in hypersonic missiles, the first initiative between the companies under a broader joint technology development arrangement.WHY IT MATTERSThis fuel-efficient rotating detonation ramjet promises to fly missiles faster-including at hypersonic speeds-and farther while decreasing costs compared to other ramjet options. Here's how: The compact design enables increased fuel or payload capacity and lowers the cost of production.Improved fuel efficiency and thrust generation extends range.Ignition is achieved at a lower speed, so smaller boosters can be used for ramjet start....