For more information, contact Joel W. Sills, Langley Research Center, joel.w.sills@nasa.gov Download the PDF version Complex mode shapes can emerge in a linear structure even when overall damping is low. This behavior can occur when two structural modes are closely spaced in frequency and are coupled through nonproportional damping. As the damping interaction increases, the…

A commercial lander that will be at the forefront of NASA’s efforts to establish a Moon Base, humanity’s first lunar outpost, has passed a series of critical tests at the agency’s Jet Propulsion Laboratory in Southern California. The tests simulated the extreme temperatures and vacuum of space, as well as the intense shaking and ear-splitting…