For almost eight decades, some of Earth’s unlikeliest astronauts have ventured beyond the atmosphere, from fruit flies and dogs to monkeys and tortoises.
Before humans ever reached space, animals led the way, giving scientists crucial clues about whether living creatures could endure radiation, weightlessness and the many dangers beyond our planet.
Their role in space research has never fully ended. Today, rats, mice, insects and sea creatures continue to live and be studied aboard the International Space Station.
The first tiny trailblazers to make the journey were fruit flies.
In 1947, the United States sent them 68 miles above Earth on a V-2 rocket to examine the effects of radiation. Their capsule returned by parachute, and every fly survived.
Two years later, in 1949, Albert II, a rhesus monkey, became the first mammal to reach space. He made it through the flight but died after his parachute failed during the return.
Then came the Soviet Union’s famous space dogs.
In 1951, Tsygan and Dezik became the first dogs to reach space and come back alive. Six years after that, Laika, a stray from Moscow, became the first animal to orbit Earth aboard Sputnik 2.
Sadly, it was a one-way trip. The technology to bring her home did not exist, and she died within hours.
America fired back in 1958 with Gordo, a squirrel monkey who survived launch, weightlessness and reentry — only for his parachute to fail. His capsule vanished into the Atlantic.
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The following year, Miss Able and Miss Baker became the first monkeys to survive spaceflight.
Able died four days later, but Baker lived until 1984 and became a beloved celebrity at Alabama’s US Space and Rocket Center, where visitors still leave bananas on her grave.
In 1960, Soviet dogs Belka and Strelka became the first animals to orbit Earth and make it back safely. Strelka later had puppies, including Pushinka, who Soviet leader Nikita Khrushchev gave to President John F. Kennedy’s daughter Caroline.
Next came Ham, an American chimpanzee trained to operate levers during flight. His 1961 mission proved a passenger could think and perform tasks in space, helping clear the launchpad for Alan Shepard to become the first American in space months later. That same year, Enos became the first — and only — chimp to orbit Earth.
France joined the menagerie in 1963, launching Félicette, a black-and-white Paris street cat who became the first and only feline to reach space. She survived but was euthanized two months later for scientific study.
In 1968, two Soviet tortoises aboard Zond 5 became the first Earth creatures to circle the Moon and return alive.
Apparently, the Russians figured slow and steady would win the space race.
After humans reached the moon in 1969, larger animal astronauts were mostly grounded, but the cosmic zoo kept growing. Apollo 17 carried five mice — Fee, Fi, Fo, Fum and Phooey — around the Moon in 1972, while spiders Arabella and Anita showed Skylab in 1973 that webs could be spun in weightlessness.
Then, in 2007, microscopic tardigrades — nicknamed “water bears” — pulled off the ultimate survival trick: enduring direct exposure to the vacuum of space.
Today, most animals sent to the International Space Station, helping researchers study bone loss, muscle wasting, are part of large-scale biomedical studies. They are housed in specialized, drawer-like habitats and tracked by numbers, barcodes or experimental groups rather than personal names
NASA calls these pioneering creatures the “unsung heroes of animal astronauts.”
