10 October 1986
Vol 234, Issue 4773

About The Cover

The Tracking and Data Relay Satellite System (TDRSS), operated for NASA by Spacecom, was used in conjunction with 64-meter radio telescopes in Australia and Japan to perform very long baseline interferometry in space. Using this technique it has been possible to obtain angular resolution equivalent to that of a radio telescope with a diameter 1.4 times the size of the earth. See page 187. [Photograph courtesy of TRW, Inc.]