150412-N-PO203-082 NATIONAL HARBOR, Md. (April 12, 2015) Henry Pickard, from the Naval Research Laboratory, explains Vanguard 1, the first satellite to be solar powered, during the Naval STEM Exposition. The expo, held in advance of the 50th annual Sea-Air-Space Exposition and co-sponsored by the Office of Naval Research and the Navy League STEM Institute, provided middle and high school students an introduction to naval STEM careers and applications through guest speakers and hands-on activities. (U.S. Navy photo by John F. Williams/Released)