the island is the location of raf ascension island, which is a royal air force station, a european space agency rocket tracking station, an anglo-american signals intelligence facility and the bbc world service atlantic relay station. the island was used extensively as a staging point by the british military during the falklands war. ascension island hosts one of four ground antennas (others are on kwajalein island, diego garcia, and cape canaveral) that assist in the operation of the global positioning system (gps) navigational system. nasa operates a meter class autonomous telescope (mcat) on ascension island for tracking orbital debris, which is potentially hazardous to operating spacecraft and astronauts, at a facility called the john africano nasa/afrl orbital debris observatory.