Dave Shayler's interest in the U.S. Gemini program began during the late 1960s while reading about the later missions of Apollo astronauts as they prepared for the first lunar landings. The skills learned, which secured their seats on Apollo, were achieved during ten Gemini missions flown between March 1965 and November 1966. From that early research he learnt that Gemini was an important stepping stone to Apollo and though short, it was a critical program not only on the way to the Moon but also in planning future programs. Even today, nearly 50 years after the final Gemini spacecraft flew, the program holds a special place in the hearts of those who worked on the project. Over the years this research continued and resulted in visits to the NASA JSC facilities and archives in Houston and the NARA records offices in Fort Worth, Texas, where many of the official Gemini documents had been retired.  Dave had the good fortune to meet and interview astronauts and engineers who worked on the program and access retired documentation from that exciting era. In 1976, as his interest in human spaceflight developed, Dave joined the British Interplanetary Society; in 1984 Dave was elected a Fellow and between 2013 and 2019 served as a member of the BIS Council. In 2020 he became the third Editor of Space Chronicle the BIS space history magazine. Dave has also has served as Chair for the BIS Library Committee and as Coordinator and Co-Chair of the annual Sino/Russian Technical Forum. In order to focus research and writing activities he formed his own company, Astro Info Service, in October 1982. Together with his writing activities this has allowed Dave to travel to the United States and Russia to tour leading spaceflight facilities, interview astronauts, cosmonauts, managers and engineers and research official documentation on various aspects of human space history, hardware and operations, including the Gemini program.