Image of the Photovoltaic Radio-frequency Antenna Module (PRAM) with a 12-inch ruler for scale. Image courtesy of U.S. Naval Research Laboratory. The U.S. Naval Research Laboratory engineers launched PRAM, the Photovoltaic Radio-frequency Antenna Module, aboard an Air Force X-37B Orbital Test Vehicle on 17 May 2020 as part of a comprehensive investigation into prospective terrestrial use...