I'll Find You...somewhere in the cold

A fifteen year-old boy becomes an astronaut despite being very young. Two years later, after he has finished training, he sets out to find new planets. But, when his ship crashes on an earthlike planet going through their own "ice age", and he has no way to get home, he meets a sixteen year-old girl living on the planet. He is determined to get back to Earth-and take her with him.