A man in black carries a small cage from the Soviet Union to the U.S. president John F. Kennedy, presenting a stray dog named Pushok as a symbol of friendship between two superpowers. The tale unfolds as a larger set of stories about a circle of stray animals whose fates will touch history, with the dogs at the center of a remarkable journey from streets to space.
In Moscow in 1960, a mysterious figure is chasing dogs, taking them away from their ordinary lives. A clever terrier mix named Strelka escapes with a friend, while Venya the dog heads to a payphone to earn a little money for themselves. Belka, a brave Samoyed, becomes entangled in the strange man’s pursuit after a voyage that begins with a circus backdrop and a rocket that looms large in their lives. During the chase, Strelka takes refuge with friends, and a pack of stray dogs—Bula the French bulldog, Mula the pug, and Pirate the wolf—join the mix, complicating the dogs’ chance to remain free. By dawn, however, the dogs are captured and transported by train toward Baikonur, where a Soviet space program training center awaits.
There, the team meets their trainer, Kazbek, Sergey Garmash, a stern but capable German Shepherd who must pick the best performers. A selection showdown ensues: Bula and Mula are initially favored, but in the final moment, Lenny secures first place, with Belka and Strelka following close behind. With the flight group chosen, Belka, Strelka, and Lenny embark on the mission that will define their legacies, while the rest wait for a chance to prove themselves.
As the mission nears launch, the dogs face personal decisions shaped by longing and loyalty. Strelka, Elena Yakovleva in memory and spirit of her star-crossed story, longs to stay in space because her supposed father Sirius is said to be among the stars. Kazbek, the seasoned trainer, makes a bold move by stowing away on the flight to join them, a quiet act that tests the line between science and devotion. The rocket carries them into a meteor shower, and a ring of fire threatens to end the mission. The crew fights back: Belka, staying calm under pressure, ultimately takes the wheel to steer the craft toward Earth, while Strelka helps extinguish the danger, and Kazbek confesses a heartfelt love for Belka as they face the peril together.
From their vantage point among the stars, the dogs observe constellations and even salute Sirius, turning their peril into a moment of quiet triumph. They survive the ordeal and make a dramatic return to Earth, celebrated as heroes. Yet the triumph is tempered by political realities: the scientists warn that Soviet propaganda won’t allow the world to know a stow-away had ridden the flight. Back on Earth, the Kennedy pets are skeptical of Pushok’s tale, until one dog notices the Cosmonaut Patch on the cushion, prompting a wish to hear the rest of the story.
Strelka returns to live with her mother, while Venya becomes a travelling storyteller, recounting the mission to any who will listen. Belka resumes her life in the circus, flying the now-repaired rocket as the showpiece, and Kazbek finds a life of companionship with Belka. In the end, happiness settles over the company as the credits roll, interleaving archival footage from the real Soviet space program with the memories of a dog-filled adventure that forever linked two eras of exploration.
