Before man ever made it to space, animals traveled there. Scientists believed that people could survive in space, but they needed to test their theories before they sent people up. The USSR and the United States were in an arms race and cold war, so the Soviets decided to send an animal up to test their theories. The USSR only used female stray dogs in their space program. They thought that stray dogs would be tougher, and they wanted females because they did not need to stand to urinate. The dogs were all small, so they could fit into the capsules. The Soviets chose dogs because they thought the animals could stand the periods of inactivity better than other animals could. The United States never used dogs; instead, they sent different species of monkeys into space. The training of the dogs involved keeping them in small containers for 15 or 20 days at a time and teaching them to eat a nutritious jelly-like food along with other training.
The first dog to orbit the Earth was called Laika; she was a three year old, stray Siberian husky mix. Laika was the only dog that the Soviets sent to die in space knowingly. They just did not have time to prepare a capsule that could stand a long period in space and the reentry. She was launched in the Sputnik 2 in 1957. The Russian government did not release until 2002 the fact that Laika died only hours after takeoff. Their former press releases had said she lasted for several days.
After Laika, a number of other dogs were also sent up into space. These were all female strays like Laika. Quite a few of the dogs survived, but a number still perished. Between 1957 and 1961, over a dozen dogs including Bars, Lisichka, Strelka, Pchelka, Mushka, Damka, Veterok, and Ugolyok were sent int space. In addition to Laika, Lisichka, Pchelka, Bars, and Muska all died in flight.
One of Strelka’s puppies was later given to President John F. Kennedy’s daughter Caroline. Other space dogs also had puppies. In 1966, Veterok and Ugolyok spent 22 days in orbit. This was the longest space flight made by dogs to date, and the record was not broken by humans until 1973. Between the 1950’s and the 1960’s, the Soviets launched 57 dogs into space; the actual number of dogs is lower than that though because some of the dogs were sent up more than once. The space dogs, Laika in particular, are commemorated on the stamps of various countries. There are also monuments to the space dogs in Russia.
Astronomy Cast has an episode on space capsules.