Phillip W. Mange
Physicist Phillip W. Mange, a pioneer of the space age, passed away on 18 June 2020, shortly after his 95th birthday. Phil’s career was launched in the 1950s when upper atmosphere and space exploration began in earnest with the advent of sounding rockets, followed by satellites. His special interest in the kinetic theory of gases motivated Phil to apply the complex theoretical concepts of Chapman and Cowling to upper atmospheric gases, thereby laying the foundation of present-day understanding of the atmospheres and ionospheres of Earth and other planets.
Phil was born in Kalamazoo, Michigan, on 5 June 1925. He graduated from Kalamazoo High School in 1943 and served in the US Army during World War II. He received his undergraduate degree from Kalamazoo College and a PhD in physics from the Pennsylvania State University. Phil then undertook postdoctoral research in Belgium under Marcel Nicolet, his PhD adviser and mentor. Phil’s duties included prominent participation in the International Geophysical Year from 1957-58. A fascinating American Institute of Physics oral history documents Phil’s exploits during the IGY, along with other historical events of that period. Phil then spent a year or so at the National Academy of Sciences before joining the Naval Research Laboratory (NRL) in March 1959 in Herbert Friedman’s Space Science Division.
Phil’s arrival at NRL provided a theoretical complement to the distinguished observational program already underway. There, he proceeded to develop and apply the concepts of diffusive separation of gases in gravitational fields, thermal diffusion, ambipolar diffusion, and the redistribution of ions forced the resulting electric field. He advanced the concept of a cloud of hydrogen surrounding Earth as the result of a flow of escaping hydrogen atoms supported by diffusion. The theoretical progress and insights laid out by Phil, sometimes in collaboration with Nicolet, were truly remarkable.
Following in the pioneering spirit of his earlier theoretical breakthroughs, Phil’s innovative experimental efforts set the stage for most of the later far-UV atmospheric remote sensing missions, such as Apollo 16 (George Carruthers’s lunar camera photographs of the full Earth), the NASA Dynamics Explorer I global imaging system, and a host of later missions, leading up to the currently flying GOLD experiment and the ICON satellite. Very quickly after his arrival at NRL, Phil’s ideas about atmospheric behavior were embodied in new experimental programs being developed at NRL as well as at NASA.
When I arrived at NRL as Phil’s postdoc in 1966, he was already principal investigator on five major satellite experiments (on board OGO I, II, III, IV, and OSO-IV) as well as six rocket experiments. The most successful of these was OGO-IV, a groundbreaking experiment that produced a large number of discoveries. Among the more outstanding achievements to come from OGO-IV were the discovery of UV radiation emanating from the F-region of the ionosphere due to the recombination of oxygen ions, which in turn laid the groundwork for the concept of remote sensing of the ionosphere (ionospheric weather); the characterization of the auroral zone during both day and night, including the morphology of proton auroras; the discovery of large plumes of atomic hydrogen emanating from hydrogen compounds in rocket exhaust, as well as detection of the premature shutdown and fuel leak from Apollo 6; and the emerging picture of geocoronal Lyman alpha emission emanating from the hydrogen cloud extending many tens of Earth radii. Phil’s experiment on OGO-III, which was placed in a highly elliptical orbit with apogee of 20 Earth radii, detected a hydrogen Lyman alpha background emission beyond the geocorona. The data displayed temporal variations in phase with the 28-day rotationally modulated solar Lyman alpha emission, convincingly demonstrating that the signal was due to backscattering of sunlight by H atoms local to the solar system, and not from a galactic source. That discovery of interplanetary hydrogen was ultimately explained as interstellar neutral gas flowing through the heliopause and into the solar system, a phenomenon previously thought to be impossible due to the ionization effects of the Sun.
Subsequently, in the 1970s, Phil began a gradual shift toward administration, helping Friedman to run the Space Science Division. He became associate superintendent, acting in that capacity until he became scientific consultant to the NRL director of research prior to his retirement in 1993.
Phil enjoyed the arts, most especially music. In retirement he worked at the Kennedy Center, a venue that allowed wonderful opportunities to enjoy music and the theater. He also maintained his interest in physics as a member of the APS Mid-Atlantic Senior Physicists Group and by tutoring students at the University of Maryland. Later, when he returned to Kalamazoo in 2008, he continued to tutor at Kalamazoo Valley Community College.
Phil was an active member of the American Geophysical Union, the American Physical Society, the American Association for the Advancement of Science, and Sigma Xi. He truly embodied the ultimate standard for the American Geophysical Union’s motto, “Unselfish Cooperation in Science.” Nicolet attested directly to this in 1984 when he accepted the Bowie Medal of the American Geophysical Union, stating: “I would like to say simply that, notwithstanding the various surprises of crossing the Atlantic, these have been years of fruitful scientific research, thanks to the collaboration of my graduate students, also my research associates. I shall mention only one of these, ab uno disce omnes: Phil Mange, who was and still remains a true scientist, and who is nevertheless willing, perhaps too often, to devote much of his time to the development of the science of others.”
Phil was one of the kindest, smartest, and least selfish persons with whom I have been privileged to work during my own half century at the Naval Research Laboratory. His many friends and colleagues are richer for having known him and poorer for his passing.
