Three teenagers (Sveta Ishenova, Sasha Ivanenko, and Fedya Druzhinin) won the All-Union Children's Space Competition. After completing the top-secret training course, they granted the right of the first children cosmic travel in history. They start on the Astra spacecraft, but their captain Egor Kalinovskiy gets ill and is sent into the isolation facility. But he is the only adult on the ship.