Ascension Island 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. In 1501, the Portuguese navigator Afonso de Albuquerque sighted the island on Ascension Day (which fell on 21 May that year) and named
Exploration of the Pacific was made by the Portuguese expeditions of António de Abreu and Francisco Serrão, via the Lesser Sunda Islands, to the Maluku Islands, in 1512, and with Jorge Álvares's expedition to southern China in 1513, both ordered by Afonso de Albuquerque from Malacca. Spanish explorer Balboa was the first European to sight the Pacific from America in 1513 after his expedition crossed the Isthmus of Panama and reached a new ocean. He named it "Mar del Sur" (literally, "Sea of the South" or "South Sea") because the ocean was to the south of the coast of the isthmus where he first