Hydrogen for Aircraft and Rockets
 By early 1945, the pace of war-needed military research had slackened. The government's laboratory at Los Alamos, New Mexico, was preparing for the first atomic bomb test in July. Johnston needed new support for his cryogenic laboratory and was receptive when the men in charge of fuels research at Wright Field approached him in the spring; agreement was soon reached on a contract, the first on hydrogen for aircraft and rockets in the United States.
Starting on 1 July 1945, the contract covered two major types of investigations. The first was hydrogen as a fuel for aircraft and rockets and was essentially engineering research. The second dealt with measurements of the physical, chemical, and thermochernical properties of hydrogen and the effect of very low temperatures on the properties of metals. This was science, the kind of work Johnston was most familiar with and which provided the research opportunities academicians seek for their graduate students. In 1948, both types of work were continued but under separate contracts. The fuel contract ended in December 1951, but the scientific properties contract continued. The contracts required bimonthly progress reports and annual summaries. In addition, special reports were written and the scientific work appeared in numerous doctoral theses and papers in scientific journals.6
The properties research contributed to the propulsion research by providing basic data needed for the theoretical aspects of propulsion research, such as thermochernical calculations of performance at various fuel/oxidant mixtures and combustion pressures, the composition of the exhaust gas and its properties for heat transfer calculations, and the properties of liquid hydrogen as a coolant.
Johnston devoted most of his time to his specialty, low-temperature equipment and properties research. The propulsion work was delegated largely to a group of engineers and technicians assisted by engineering students, all in the charge of a chief engineer. Three chief engineers served during the course of the propulsion work: Marvin L. Stary from early in the contract until 1949; Willard P. Berggren from 1949 to 1950; and William L. Doyle from 1950 to 1951. The rocket work involved, at one time or another, 18 research engineers, 21 students, 13 technicians, 7 administrative personnel, and 3 consultants. Figure 4 is a photograph of the rocket laboratory staff about 1950 and shows a typical mix of skills: 3 engineers, 3 engineering students, and 5 technicians.
Many aspects of the hydrogen work at Ohio State are beyond the scope of our subject, and only the work directly related to propulsion will be described . This is divided into five topics: hydrogen-air experiments, hydrogen-oxygen rocket performance, hydrogen-oxygen rocket cooling, pumping liquid hydrogen, and hydrogen-fluorine rocket performance.