Animal experiments have always been an important component of space exploration. Since the 20th century, the former Soviet Union and Russia have achieved major advances in the human space industry, which would not have been possible without the knowledge gained from animal experiments. Animal experiments were initially used to evaluate the possibility of humankind exploring space. “ Animal astronauts” were sent into space as the “ pioneers” of human space exploration. Such events were milestones in the development of the aerospace industry and greatly contributed to the construction of crewed spacecraft and space stations. This article reviews the development of space animal experiments in the former Soviet Union and Russia since the 20th century.