Bill Gordon, the engineer who conceived, built and managed the Arecibo Observatory in Puerto Rico, died of natural causes Feb. 16 in Ithaca, N.Y. He was 92. Gordon was serving on Cornell University’s engineering faculty when, in the late 1950s, he began designing a very large radar system capable of studying the properties of the Earth’s ionosphere out to distances of several thousand miles, a region of the Earth’s atmosphere of great interest in the post-Sputnik era. Gordon realized that such a telescope could also contribute significantly to the study of the solar system and to the then relatively new field of radio astronomy. Taking a technical gamble, he and his Advanced Research Project Agency (ARPA, the predecessor of DARPA) sponsors designed a telescope with a 1,000-foot fixed spherical reflector and a movable focusing system that is suspended above the reflector. The resulting structure was a marvel of civil engineering. It was so large that the Empire State Building could fit sideways and the Washington Monument could easily fit standing from the dish bottom to its focal point. The observatory was inaugurated in 1963 when the first measurements of the properties of the ionosphere were made. Within a year of opening, the telescope was used to determine the planet Mercury’s rotation period and, after radio pulsars (rotating neutron stars) were discovered in 1967, played a prominent role in studying the properties of these unique objects. The first binary pulsar was discovered using Arecibo in 1974, leading to the confirmation of the existence of gravitational radiation and the 1993 Nobel Prize for its discoverers. The telescope itself held a prominent role in the film “Contact” (1997) and the title role in the James Bond film “GoldenEye” (1995). At Arecibo’s 40th Anniversary in 2003, Gordon said: “When we were talking about building [the telescope] back in the late ’50s, we were told by eminent authorities it couldn’t be done. We were in the position of trying to do something that was impossible, and it took a lot of guts, and we were young enough that we didn’t know we couldn’t do it. It took five years from idea to dedication, and that is short.” “But we were in the right place at the right time and had the right idea and the right preparation. We had no rules or precedents.” The observatory, now operated by Cornell through the National Astronomy and Ionosphere Center for the National Science Foundation, has enjoyed two major equipment upgrades since opening, and it remains a unique and vital scientific tool. Today, it searches for asteroids and comets aimed at the Earth. Gordon served as the observatory’s director from 1960 to 1965. Using the radar signals returned by charged particles, he studied the temperature, density, chemical composition and other properties of the ionosphere, which he called “both the gateway to space and our first line of defense against the deadly radiation streaming toward us from the Sun and other stars.” William E. Gordon was born Jan. 8, 1918, in Paterson, N.J. He earned a bachelor’s degree from Montclair State Teacher’s College, a master’s degree from New York University and his doctorate at Cornell. During World War II, he served in the U.S. Air Force as captain and electronics engineer; and worked with the National Defense Research Committee on the effects of weather on radar range. He came to Cornell in 1948. In 1950, Gordon published (with Henry G. Booker) the theory of radio wave scattering in the troposphere. In 1966 Gordon moved to Rice University, where he served as a professor, dean, provost and vice president, retiring in 1985. He is one of only two Rice faculty members to be honored with the title Distinguished Emeritus Professor. Gordon was a member of the National Academy of Sciences and the National Academy of Engineering; a foreign associate of the Engineering Academy of Japan; and a fellow of the American Academy of Arts and Sciences, American Association for the Advancement of Science, American Geophysical Union and Institute of Electrical and Electronics Engineers. Among many international honors, Gordon received the 1966 Balth van der Pol Gold Medal, the 1984 Arctowski Gold Medal, a 1985 USSR Academy of Sciences Medal for distinguished contributions in international geophysical programs and the Centennial Medal of the University of Sofia in 1988. In 1941, he married Elva Freile. She died in 2002. Their survivors include their two children, Larry and Nancy; four grandchildren and three great-grandsons. In 2003, he married Mary Elizabeth Bolgiano. For more information, visit: www.cornell.edu