Located inside a high-tech NASA laboratory in Cleveland is something you could almost miss at first glance: a small-scale, fully operational jet engine to test new technology that could make aviation more sustainable. The engine’s smaller size and modestly equipped test stand means researchers and engineers can try out newly designed engine components less expensively compared to using a more costly full-scale jet engine test rig. Named DGEN380 Aero-Propulsion Research Turbofan, or DART, the engine is tiny enough to fit on a kitchen table, measuring at just 4.3 feet (1.3 meters) long. That’s a…