This spacecraft was the second in a series of spacecraft designed to further the development of an Earth orbiting system for the planned manned space program.

A radio station in Bonn, Germany, was among the first to pick up the signal. On the 3rd orbit, a Swedish radio station confirmed this.

The spacecraft carried two dogs, Belka and Strelka, 40 mice, 2 rats and a variety of plants on-board. The spacecraft returned to earth the next day and all animals were recovered safely. The spacecraft also carried a television camera which took images of the dogs.

Shortly after the landing, one of Strelka's puppies was sent to Jacqueline Kennedy as a present from the Soviet Union.