A screen adaptation of Sergey Mikhalkov's play "The First Three, or the Year 2001". Three schoolchildren have been selected for the first space flight. Piloting the ship "Astra", the kids bravely overcome all the difficulties of their mission - an attack of meteorites and a gas leakage. Finally, they learn about the secret of their flight, a secret the adults were hiding from them. The composer Alexei Rybnikov and the poet Igor Kokhanovsky wrote several romantic songs for the film, which were originally performed by the "True Friends" vocal-instrumental group. The songs became musical hits of the time. The songs "Do you believe me or not?" and "The Milky Way" are often still played on Russian radio to this day.