APO resource visit counts have been improved. For more information, see our Policies & Guidelines


The SIGINT satellites of Pine Gap: conception, development and in orbit

15 Oct 2015

Pine Gap’s initial and still principal importance to the United States lies in its role as a ground control and processing station for geosynchronous signals intelligence satellites. Nine geosynchronous SIGINT (signals intelligence) satellites have been operated by Pine Gap over the past 45 years. That role has grown as the satellites and their associated ground systems have developed in size, capacity and range of applications far beyond what was envisaged half a century ago – or understood by the host government that accepted the base at that time. During the ground station site selection process in 1966, one of the main criteria was that the horizon angle from the floor of the selected location and over the surrounding hills ‘should not exceed six degrees’. From Pine Gap’s latitude of 23.80° S and longitude of 133.74° E, this would allow connectivity (for both command and control and for data reception) with satellites stationed as far west as 60° E (or as far east as 153° W if ever required). The stations of the current three Orion SIGINT satellites controlled by Pine Gap make possible the collection of a wide range of signals across more than half the surface of the planet outside the polar regions – every continent except the Americas and Antarctica, and every significant region of contemporary US military concern. There is now just one US highly integrated geosynchronous signals intelligence satellite system, with comparable satellites operated by Pine Gap and Menwith Hill, with much greater capacities and much more focussed military roles than their Cold War equivalents

Publication Details
Published year only: 
Subject Areas
Geographic Coverage