NASA

 NASA (National Aeronatics and Space Administration) is the agency of the United States government, responsible for the country's civilian Space program, aerospace, and aeronautics research.

History
NASA worked with S.H.I.E.L.D. at the Joint Dark Energy Mission Facility in the Mojave Desert to research the Tesseract, along with Erik Selvig to attempt to create an object with unlimited self-sustaining energy.