Cosmic Voyage presents a 1946 Soviet Union that has transitioned from post-revolutionary struggle into a technologically triumphant superpower. Set in Moscow, the world is dominated by the Tsiolkovsky Institute of Interplanetary Communication, a massive scientific hub dedicated to the conquest of the moon. The film depicts a high-tech society where monumental architecture, such as the (never-built) Palace of the Soviets, anchors a skyline of progress, and space travel is treated as a matter of inevitable national duty.

The film’s technological dynamics are remarkably grounded for the era, largely due to the technical supervision of rocket pioneer Konstantin Tsiolkovsky. The Earth of 1946 is portrayed as the undisputed launchpad for human expansion, specifically through the "Joseph Stalin" and "Marshal Voroshilov" rockets. Earth serves as the political and command center, with the entire population seemingly focused on the success of the lunar mission. The timeline diverges from reality primarily through the accelerated development of heavy-lift rocketry and the completion of grand Stalinist architectural projects that were halted by World War II.

Predictively, the film is a "missing link" in hard sci-fi. It correctly anticipated the use of multi-stage rockets and the necessity of animal testing (rabbits and cats) before human flight. While the "liquid acceleration chambers" to mitigate G-forces remain speculative, the film’s depiction of weightlessness and low-gravity locomotion—achieved through stop-motion—is considered one of the first semi-accurate cinematic representations of physics in space. However, it missed the mark on the lunar environment, suggesting the discovery of "frozen oxygen" in lunar crevasses as a plot device for survival.