https://theintercept.com/2017/08/19/nsa-spy-hub-cia-pine-gap-australia/

An investigation, published Saturday by the Australian Broadcasting Corporation in collaboration with The Intercept, punctures the wall of secrecy surrounding Pine Gap, revealing for the first time a wide range of details about its function. The base is an important ground station from which U.S. spy satellites are controlled and communications are monitored across several continents, according to classified documents obtained by The Intercept from the National Security Agency whistleblower Edward Snowden.

Together with the NSA’s Menwith Hill base in England, Pine Gap has in recent years been used as a command post for two missions. The first, named M7600, involved at least two spy satellites and was said in a secret 2005 document to provide “continuous coverage of the majority of the Eurasian landmass and Africa.” This initiative was later upgraded as part of a second mission, named M8300, which involved “a four satellite constellation” and covered the former Soviet Union, China, South Asia, East Asia, the Middle East, Eastern Europe, and territories in the Atlantic Ocean.