The extensive experience in working initially with various biological samples and then subsequently with dogs, monkeys, and cosmonauts, coupled with the development of scientific hardware and equipment, brought Soviet medical and biological research to the attention of the international scientific community. This interest catalysed close cooperation in the early 1970s, not only with scientists from socialist bloc countries but also with those from the USA and France in the realm of space biomedicine. The participation of ESA scientists materialised at a later stage for several reasons, which will be expanded upon in this chapter, along with the Soviet interest in cooperation with Europeans and the factors that prompted the latter to embark on joint projects.