Stennis Space Center (SSC) is one of ten NASA field centers in the United States. Located in Hancock County, in southwest Mississippi, about 80 kilometers east of New Orleans, Louisiana, the John C. Stennis Space Center is the primary center for testing and flight certifying rocket propulsion systems for the Space Shuttle and future generations of space vehicles. All Space Shuttle Main Engines must pass a series of test firings at Stennis Space Center prior to being installed in the back of the Orbiter. Stennis is also NASA's lead center for commercial remote sensing within the Mission to Planet Earth Enterprise. It was previously called the Mississippi Test Facility and used as the static test site for Saturn and Nova-class launch vehicles.