Robert A. Citron, often called Bob Citron (September 14, 1932 – January 31, 2012) was an American entrepreneur and aerospace engineer who was born in Brooklyn, New York, and educated at the University of the Philippines (liberal arts) and aeronautical engineering from Northrop University (1953–1959).[1] Citron helped establish and manage the Smithsonian Astrophysical Observatory's Operation Moonwatch and Precision Optical Satellite Tracking Programs (STP) after the launch of Sputnik I in 1957.[1] He founded or co-founded five companies dealing with documentary film production (Limpopo Films Pty. Ltd. – 1964), publishing (Adventure Travel, Inc. – 1976), space research and space logistics support (SPACEHAB, Inc. – 1983), reusable satellite launch systems (Kistler Aerospace Corporation – 1993), and Lunar transportation and logistics (Lunar Transportation Systems, Inc. – 2004). Citron also started three nonprofit foundations dealing with scientific field research (Educational Expeditions International with Clarence Truesdale, superintendent of Vermont public schools, in 1971, which became Earthwatch,[2] short-lived phenomena (Center for Short-Lived Phenomena – 1975), and the study of the long-term future of humanity Foundation For the Future – 1996). He died on January 31, 2012, at his home in Bellevue, Washington, at the age of 79, due to complications from prostate cancer.