P.L. Kapitsa: “I consider the oxygen problem to be the most important one for the development of our industry”

The article describes P.L. Kapitza’s outstanding contribution to the production of liquid oxygen, from the birth of the idea to use water turbine as a constructive prototype to the development of an industrial method for producing liquid oxygen by air liquefaction in low-pressure units. The scientist showed remarkable persistence and determination in overcoming difficulties associated with introducing “new” technology in the factory’s operations. It is emphasized that Kapitza intended to implement the results of the latest scientific developments in addressing a broad range of tasks of the national economy, particularly in the hard years of the Great Patriotic War. Kapitza’s epistolary heritage is abundant, including detailed descriptions of his studies and experiments aimed to achieve the desired goal of “providing the country with cheap oxygen.” The article contains many of his quotes.