There was a time when animals were sent to space to test the survivability of spaceflight. From the present point of view, it seems crazy to me, but the story of animals in space is much older than one thinks. Animals had been used in aeronautic exploration since 1783 when the Montgolfier brothers sent a sheep, a duck and a rooster aloft in a hot air balloon (source). However, the following story is from the early 60s: »On the morning of January 31, 1961, in south Florida, a 5-year-old chimpanzee — dubbed »Ham« by his handlers — ate a breakfast of baby cereal, condensed milk, vitamins and half an egg. Then the unassuming 37-pound primate went out and made aeronautic history: Aboard a NASA space capsule, traveling thousands of miles an hour almost 160 miles above the Earth, he became the first chimp in space.« The complete story is on LIFE’s website and is worth reading about.