The film starts in Baikonur. A female dog is captured while trying to find something to feed her puppies. She is named Laika and brought to a local spaceport. Professor Voroljov and his assistant Kokotov begin preparing Laika for space travel. On the day before the launch, Laika manages to get out of her cage and visits the space rocket. Then she returns for her puppies and smuggles them into the rocket.