HOMER J. STEWART (1915 - 2007) INTERVIEWED BY JOHN L. GREENBERG October-November 1982 INTERVIEWED BY SHIRLEY K. COHEN November 3, 1993 1979 ARCHIVES CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California Subject area Engineering, aeronautical engineering Abstract Two interviews with Homer J. Stewart, aeronautical engineer and Caltech Professor of Aeronautics, 1942-1980, and Caltech alumnus (PhD, 1940). The interview by John L. Greenburg is in four sessions in October and November of 1982. A supplemental interview was conducted by Shirley K. Cohen in November 1993. The first interview covers Stewart’s youth and education (B.Aero.E., University of Minnesota, 1936) and his early interest in aeronautic technology. Comes to Caltech for graduate study in aeronautics, 1936-1940 (PhD, 1940); courses with faculty members W. Smythe, R. C. Tolman, E. T. Bell, M. Ward, H. Bateman. Comments on critical roles of Theodore von Kármán and Clark Millikan in establishment of graduate program known as GALCIT [Guggenheim Aeronautical Laboratory at the California Institute of Technology]; creation of GALCIT wind tunnel for testing; advancement of aeronautical engineering education; and linking of GALCIT to burgeoning California aerospace industry. Von Kármán’s identification of new technologies; his bridging of industry and http://resolver.caltech.edu/CaltechOH:OH_Stewart_H academe; similar integrating approach applied to founding of Jet Propulsion Laboratory [JPL]. Discusses GALCIT’s role in the development of commercial aviation in the 1930s. Appointment to professorial rank (1942) and wartime teaching and research on meteorology; comments on Irving Krick at Caltech. Discusses beginnings of rocketry at Caltech and his own pioneering contributions; work of Frank Malina and H. S. Tsien. Postwar separation of Caltech and JPL and formation of NASA [National Aeronautics and Space Administration]; takes half-time position at JPL. 1950s top secret work for government on guided missile and satellite programs, including Atlas, Polaris, Jupiter; various controversies over competing missile designs, especially Vanguard, during space race with Soviets. Advising on Apollo lunar program. His work on windmill technology. The 1993 interview captures in fuller detail Stewart’s memories of his service to government agencies and congressional committees during World War II and the years of the Cold War. It includes further reminiscences of Von Kármán and Clark Millikan, and other Caltech colleagues Maurice Biot, Fritz Zwicky, and Howard McCoy; the Caltech wind tunnel; details of airplane design; and observations on the establishment and growth of California’s aerospace industry. A list of Stewart’s government and industry affiliations is included as an appendix. Administrative information Access The interview is unrestricted. Copyright Copyright has been assigned to the California Institute of Technology © 1986, 1998, 2007. All requests for permission to publish or quote from the transcript must be submitted in writing to the University Archivist. Preferred citation Stewart, Homer J. Interview by John L. Greenberg. Pasadena, California, October-November 1982. Interview by Shirley K. Cohen. Altadena, California, November 3, 1993. Oral History Project, California Institute of Technology Archives. Retrieved [supply date of retrieval] from the World Wide Web: http://resolver.caltech.edu/CaltechOH:OH_Stewart_H Contact information Archives, California Institute of Technology Mail Code 015A-74 Pasadena, CA 91125 Phone: (626)395-2704 Fax: (626)793-8756 Email: [email protected] Graphics and content © 2007 California Institute of Technology. http://resolver.caltech.edu/CaltechOH:OH_Stewart_H Four distinguished engineers at Caltech commencement, 1947. (From L-R:) Clark B. Millikan, professor of aeronautics and successor to Theodore von Kármán in 1949 as the second director of GALCIT; Louis G. Dunn, professor of aeronautics and first director of the Jet Propulsion Laboratory; Frederick C. Lindvall, professor of electrical and mechanical engineering and chairman of Caltech’s division of engineering; and Homer J. Stewart, professor of aeronautics. Caltech Archives, Lee A . DuBridge Papers. http://resolver.caltech.edu/CaltechOH:OH_Stewart_H CALIFORNIA INSTITUTE OF TECHNOLOGY ARCHIVES ORAL HISTORY PROJECT INTERVIEW WITH HOMER J. STEWART BY JOHN L. GREENBERG PASADENA, CALIFORNIA Copyright © 1986, 2007 by the California Institute of Technology http://resolver.caltech.edu/CaltechOH:OH_Stewart_H Stewart-ii TABLE OF CONTENTS INTERVIEW WITH HOMER J. STEWART Session 1 1-24 Family background; father student of R. A. Millikan at Chicago (early 1900s); growing up in Kansas, Minnesota, Iowa; freshman year at University of Dubuque (1931-1932); transferring to University of Minnesota; father’s interest in communication and electric power applications; enthusiasm as schoolboy for aeronautics; pinch-hitting for Minnesota professor on instrumentation contract for high- altitude balloon; Auguste Piccard; Minnesota advanced in aero technology; practical design experience for students on faculty consulting projects; Professor Howard Barlow’s recommendation of Caltech for graduate study. Teaching assistantship at Caltech wind tunnel (1936-1940); effectiveness of college math courses as preparation for E&M; courses with Smythe, Tolman, Bell, Morgan Ward, Bateman; Bateman’s contributions to aerodynamics theory. Von Kármán and Clark Millikan’s capacity for higher mathematics combining with contacts outside for applications of aeronautics; as first-year grad student, helping Kármán on dynamical analysis of the Macon (dirigible) disaster for Congress; aerodynamics theoreticians of 1920s; small scale of aeronautics business before World War II; Douglas first company to hire aerodynamic engineers (mid-1930s); running performance analysis of Navy flying boat model in GALCIT wind tunnel with Bill Sears; C. Millikan’s strong role in building up wind tunnel as operating resource; National Research Council’s seed money for first Caltech rocket projects; Kármán as seminal influence, C. Millikan turning ideas into going concerns. Kármán’s personality; his English; “cows” for “chaos;” turning off hearing aid to end discussion; Frank Malina’s birthday present of 1940 cartoon of the group; Kármán’s concern with structures as well as aerodynamics; his impeccable social manners; patience with students; seeking out Allen Puckett to work on Army’s supersonic wind tunnel design; JPL’s review committee for Air Force guided missile projects; Puckett’s salutary effect on Hughes’ business; the top-level view of government and business at Caltech. Session 2 25-45 Other aspects of von Kármán’s era: his broad organization of aeronautics department to include new technological areas for extension of applications and new disciplines; cross-fertilization of ideas; bringing industry problems into Caltech; similar integrating functions for GALCIT No. 1 and JPL (until 1960). GALCIT and commercial aviation in late 1930s; fortunate timing of theoreticians’ structural ideas; insect interference with British flight test wing panels; importance of low-turbulence wind http://resolver.caltech.edu/CaltechOH:OH_Stewart_H Stewart-iii tunnel data for understanding aerodynamic characteristics; shift in wind tunnel use from academic demonstration to 100 percent industrial testing through end of WIT; teaching its use in 1960s to auto industry. Benefits of early exposure to electrical engineering and electronics; testing center of gravity with child’s balsa wood models; appreciation of experimental process; risks of attempting computer calculations of turbulence flows; limitations of integrated computer weather forecasting; modern aerodynamicists’ efforts in problems of non-isotropic turbulence. GALCIT graduates in industry and academic life; war role changing Kármán’s relation to Caltech; publication outlets for GALCIT research: Institute of Aeronautical Sciences, Proceedings of National Academy. As grad student, teaching class in dynamic meteorology supervised by MIT expert, Rossby; part- time job with Weather Bureau; thesis research on atmospheric phenomena responsible for periodicity of high-pressure zones; wartime censorship of paper from Stanford seminar; assistant professor after PhD (1940), coping with wartime teaching load; applied mathematics and cross- disciplinary studies at Caltech and eastern schools. Session 3 46-70 Checking ASME Transactions of 1930s; Charles Sadron’s experiments with salad oil tunnel (1932); his sabotage of V-2 bomb production as German war prisoner; theoretical work of NACA aerodynamicists (1920s); Draper at MIT working on precision guidance and control; Kármán’s interest in structures; Lockheed, Douglas, Boeing all adopting Kármán’s group’s ideas on thin-sheet structures; aerodynamic ideas often too complex for immediate use; 1980s research on heat impulses to control boundary layer problem; GALCIT-NACA relationship in 1930s; NACA’s dismay at Caltech documentation of effects of turbulence level on lift and drag; Caltech’s low-turbulence wind tunnel designed primarily for efficiency; performance analyses with Bill Sears useful to industry. Kármán-Biot text on engineering mechanics a milestone (1940); influence of Timoshenko’s structure theories on later work at Caltech. Career in meteorology beginning with Rossby’s tutelage; Irving Krick’s success in forecasting for clients biased toward fair weather or rain; bitter attitude of Weather Bureau forecasters, including Rossby; charges of fakery; Krick vindicated