Spacecraft radar tracking. Technician operates a radar dish antenna used to track spacecraft which travel to the Moon and other planets. It forms part of the Deep Space Instrumentation Facility (DSIF), a system of sending commands to, and receiving scientific data from, spacecraft which are hundreds of millions of kilometres from Earth. The DSIF has sites at Goldstone, USA (seen here), Woomera, Australia, and Krugersdorp, South Africa. Radar (an acronym for Radio Detection And Ranging) systems calculate the distance to an object by transmitting an electromagnetic pulse and measuring the time it takes for a reflection from the object to return. Photographed in 1963.