Dr. Paul Song, Professor in Physics & Atmospheric Science at the University of Massachusetts Lowell, presents "Radio Technology in Space Explorations" at the MIT Earth Resources Laboratory on May 6, 2016. "When radio waves propagate through an ionized medium, its properties undergo gradual changes and reflection occurs at locations where the local plasma frequency equals the wave frequency, providing a means to probe remotely and in-situ space plasma conditions. Furthermore, mostly because of their lower frequencies and longer wavelengths compared to light waves, radio waves are able to penetrate deeper and hence provide information about a thicker medium. Over the past decades, UMass Lowell has built more than 100 ground-based ionospheric radio sounders for institutions worldwide monitoring the ionospheric conditions. A major breakthrough in space-borne radio instrumentation occurred when the NASA IMAGE satellite was launched in 2000. It carries for the first time a Radio Plasma Imager or RPI, built by the UML to remotely measure Earth’s space plasma up to distances of several Earth radii. The UML team also started developing a proto-type ice penetrating radar for the NASA Jupiter Icy Moon Orbiter program. The team has finished a high power transmitter on the DSX satellite for the Air Force. The radio instrumentation development, driven by these space applications, uses more and more advanced technologies in order to reduce size, weight and cost, and to increase functionality, reliability, precision and accuracy."