The John C. Stennis Space Center (SSC), located in Hancock County, Mississippi, at the Mississippi-Louisiana border, is NASA's largest rocket engine test facility. The Center is home to many government agencies and private companies, with the United States Navy being the largest element. The visitor center for the Stennis Space Center is known as "StenniSphere" with exhibits focusing on the activities of NASA, space, space exploration, science, geography, weather and more.