The Poker Flat Research Range (PFRR) is a launch facility and rocket range for sounding rockets in the U.S. state of Alaska, owned and operated by the University of Alaska Fairbanks (UAF) Geophysical Institute since 1948. The world's largest land-based rocket range, it is situated on a 5,132-acre (20.77 km²) site located approximately 30 miles (50 km) northeast of Fairbanks and is operated under contract to the NASA Wallops Flight Facility. Since its inception PFRR has been closely aligned and funded by the Defense Threat Reduction Agency and its predecessor, the Defense Nuclear Agency (DNA). Other range users include the United States Naval Research Laboratory (NRL), the Air Force Geophysics Lab (AFGL) and a number of Universities and research laboratories. More than 1,700 launches have been conducted at the range to study the Earth's atmosphere and the interaction between the atmosphere and the space environment .