50 years ago Belka and Strelka were two dogs who were onboard the Sputnik-5 spacecraft when it broke into orbit on August 19, 1960, circled the Earth 17 times and returned home.
Accompanying them were two lab rats and forty mice, as well as a life support system, instruments and other equipment.
Before the first human launch was approved, two spacecraft with a dog and a mannequin onboard had been sent into orbit. Their missions were almost exactly the same as that of Yury Gagarin. With a good deal of irony Gagarin later remarked that he couldn’t make up his mind whether he was the first man in space, or the last dog.