[Problem of "biological compatibility" of crew members during prolonged space flight and possible directions for its solution].

The concept of biological compatibility of men can be defined as a phenomenon which includes an effect (that might be favorable or unfavorable) of one individuum on the other via trace amounts of chemicals released into their environment and micro-organisms. The paper presents the main results of studies of biological compatibility of crewmembers of space vehicles and outlines possible directions of research to be carried out in this area.