Currently NASA science missions send data back to earth using the Deep Space Network . This network currently consists of very large antennas, from 34-meters to 70-meters in diameter. As more and more missions are flown, and the quantity of data increases, the DSN must keep pace. An architecture proposed to meet these new requirements consists of many, many small antennas, each of which can receive a part of the science signal. When all the parts are added together, the total can be made much greater than current capabilities if many antennas are used.  This technique is called “arraying”. As part of the development of this new DSN, we are developing multiple possible sites for the location of the new antenna array.

The western United States will not be the only site for the new antenna array.  It is required that two other similar sites be at equidistant locations around the world.  So while one site will be in the western U.S., others, maybe in South Africa or Spain and central Australia, will also be constructed.  Having three locations ensures that a distant spacecraft has direct “line of sight” with one of the sites 24 hours a day, every day ensuring continuous communications.

The locations selected for array sites are approximately 120 degrees apart in longitude, which enables continuous tracking with a suitable overlap for transferring the spacecraft radio link from one complex to the next.

Other criteria in location selection are weather, terrain, and isolation.  To avoid rainstorms, which may affect data reception, we are looking for dry, desert areas.  To enable multiple antennas to be built in the same location we need a large flat landscape.  And lastly, to protect our antennas and their reception capability when dealing with very weak radio signals transmitted from spacecraft over huge distances, we need ‘radio quiet’.  Sites selected must be away from the ‘noise’ generated by large populations with radios, televisions, microwave ovens and other radio frequency interference.

Each antenna will be 12 meters, (approximately 39 feet) in diameter, and up to 400 of them will occupy one site.  To accommodate these, along with the support buildings, it is estimated that each site will cover over 500 acres.

The science data from spacecraft in the solar system is currently being received by the existing DSN. We plan for transition of science support to begin in 2012 as the array filled with the first antennas, with full operation of this array in 2014.