In January of 1941, Roger was asked to join a small group of researchers at the Mt. Wilson Observatory to undertake government-funded research and development under the auspices of the National Defense Research Council (NDRC). He was offered a position as an optical engineer and worked at the Mt. Wilson Observatory from 1941 to 1945. During his first years on the Mt. Wilson team, Roger conducted optical work and contributed to the development of inventions under Section 16.1 of the NDRC, an optics research compartment that was overseen by George R. Harrison.

Roger spent most of this time deciphering the ways and means of designing and making optics, including the development of the Schmidt-Cassegrain optical arrangement for telescopes that would later revolutionize the manufacture of amateur-level telescopes. His first project involved optical sighting devices, with particular focus on binocular scanning instruments. From there he worked on the development of practice equipment to simulate combat situations, as well as the design of training programs and classroom materials to prepare for the defense of bombers from other aircraft. Following that, Roger helped refine the optimal process for the preparation and manufacture of roof prisms.

Another intriguing project that Roger worked on during the war was subjected to so much secrecy that he never found out what became of it. He later heard from an acquaintance that the matter was indeed of interest and discovered little else about it, but later theorized that the idea might have had practical applications for earth-orbiting satellites:

“I recall playing with a sheet-metal corner-cube mirror and radio waves in the 1 to 3 cm wavelength class along in 1942 – this with the help of Jesse DuMond and his set-up in Bridge. Jesse and I wrote a paper of sorts which was sent to Radiation Labs at MIT when DuBridge was in charge there. Ted Dunham submitted the paper to someone and we only heard that the matter was too secret to even tell us if the matter was not being worked on.”