Korabl-Sputnik 2 (Russian: Корабль-Спутник 2 meaning Ship-Satellite 2), also known as Sputnik 5 in the West, was a Soviet artificial satellite, and the third test flight of the Vostok spacecraft. It was the first spaceflight to send animals into orbit and return them safely back to Earth. Launched on August 19, 1960 it paved the way for the first human orbital flight, Vostok 1, which was launched less than eight months later.
Korabl-Sputnik 2 was the second attempt to launch a Vostok capsule with dogs on board. The first try on July 29 had failed when the R-7 launch vehicle suffered a malfunction of one of its strap-on boosters. A combustion chamber broke apart during ascent, causing the strap-on booster to lose thrust and separate from the rest of the booster, which then crashed downrange. Both dogs were killed. The failure was believed to have been caused by longitudinal vibration which resulted in the combustion chamber disintegrating. Vibration had been responsible for several previous R-7 failures and this accident caused a considerable uproar since the problem was supposedly fixed.
The launch of Korabl-Sputnik 2 occurred on 19 August 1960, using a Vostok-L carrier rocket. Official sources reported the launch time to have been 08:44:06 UTC, however Sergei Voevodin gave it as 08:38:24. A radio station in Bonn, West Germany, was among the first to pick up signals from the spacecraft, which were confirmed on the third orbit by a Swedish radio station.
The spacecraft carried two dogs, Belka and Strelka, 40 mice, two rats and a variety of plants, as well as a television camera which took images of the dogs. The spacecraft returned to Earth at 06:00:00 UTC on 20 August, the day after its launch, although telemetry revealed that one dog had suffered seizures during the fourth orbit. Thus, it was decided to limit the first manned flight to three orbits. All of the animals were recovered safely, and a year later Strelka had a litter of puppies, one of which was sent to First Lady Jacqueline Kennedy as a goodwill present from the Soviet Union. President Kennedy's advisors initially opposed taking the dog for fear that the Soviets might have planted microphones in its body to listen in on national defense meetings.