Researchers at NASA's Langley Research Center in Hampton, Va., use all sorts of tools and techniques to learn more during the development of aircraft and spacecraft designs.
In this photo, engineers led by researcher Greg Gatlin have sprayed fluorescent oil on a 5.8 percent scale model of a futuristic hybrid wing body during tests in the14 by-22-Foot Subsonic Wind Tunnel.
The oil helps researchers "see" the flow patterns when air passes over and around the model. Those patterns are important in determining crucial aircraft characteristics such as lift and drag.
Explore further: Smooth sailing: Space launch system giving Marshall, Langley wind tunnels a workout