Antarctic Submillimeter Telescope and Remote Observatory, or AST/RO, was a 1.7 meter diameter off-axis telescope for research in astronomy and aeronomy at wavelengths between 0.2 and 2 mm. The instrument operated between 1994 and 2005 at the South Pole with four heterodyne receivers and three acousto-optical spectrometers. It was replaced by the 10-m South Pole Telescope. AST/RO operated as part of the Center for Astrophysical Research in Antarctica (CARA), an NSF Science and Technology Center. It was funded in 1989 by the NSF Office of Polar Programs after a successful proposal by A. A. Stark, J. Bally, and R. W. Wilson of AT&T Bell Laboratories, T. M. Bania and A. P. Lane of Boston University, and K.-Y. Lo of the University of Illinois. AST/RO was the first radio telescope on the Antarctica plateau to operate throughout the year. As such, it has played a pioneering role in testing instrumentation, characterizing the site, and developing protocols that have paved the way for newer telescopes to exploit the South Pole: the best location on Earth for observations in the submillimeter band. Telescope and instruments The AST/RO telescope was located on the roof of a single story support building 20m long and 4m wide. To reduce the buildup of snow drifts, the building was mounted on steel columns raising it to an elevation of 3m above the icecap. The AST/RO building was located in the so called Dark Sector of the Amundsen Scott South Pole Station. This is an area located about 1km from the living facilities to ensure it has low light and radio noise pollution, even by South Pole standards. The AST/RO building was divided into six rooms. All receivers the participated in AST/RO observations, were mounted on an optical table suspended from the telescope in a Coudé room. In general, virtually all equipment was located inside the support building and thus was protected from the harsh climate. The AST/RO building consumed an average of 24kW of power that was supplied by the powerplant at the station. The telescope had an alt-azimuth mounting and a 1.7m primary reflector. It had an offset optical design providing a clean radio beam and allowing the mounting of large receivers in a warm Coudé room protected from the harsh external environment. At 492 GHz, it had a beamsize of 96 arc seconds, big enough for large-scale mapping programs but still able to observe nearby galaxies.