ESRO (European Space Research Organisation) is an organization formed in 1962 by 10 European nations plus Australia, which made available its rocket-firing range at Woomera. Between 1968 and 1972, ESRO launched seven satellites – Iris (ESRO-2B), Aurora (ESRO-1A), HEOS-1, Boreas, HEOS-2, TD-1A, and ESRO-4 – using NASA rockets. In 1975, ESRO and its sister organization ELDO (European Launcher Development Organisation) merged to form ESA (European Space Agency).