For decades, animals served as intrepid pioneers in the quest for space exploration, undertaking missions that helped scientists understand the effects of space on living organisms long before humans ventured into orbit.
These early animal astronauts faced significant risks, with many missions proving fatal. In 1947, fruit flies were among the first creatures launched into space aboard a V-2 rocket to study radiation effects. They survived their suborbital flight. In 1949, Albert II, a rhesus monkey, became the first mammal in space, though he died upon parachute failure during descent.
The Soviet Union also utilized dogs in its early space program. Tsygan and Dezik were the first canines to reach space and return safely in 1951. Six years later, the stray dog Laika became the first animal to orbit Earth aboard Sputnik 2, a mission from which she did not return.
America followed with its own animal astronauts. In 1958, a squirrel monkey named Gordo survived launch, weightlessness, and reentry, but his capsule was lost at sea due to parachute failure. The following year, monkeys Miss Able and Miss Baker became the first of their species to survive spaceflight. Able died shortly after, but Baker lived until 1984.
Significant milestones were achieved in 1960 when Soviet dogs Belka and Strelka orbited Earth and returned safely. This success was followed by the American chimpanzee Ham in 1961, who was trained to perform tasks during his suborbital flight, demonstrating that sentient beings could operate in space. This mission helped pave the way for Alan Shepard's historic flight months later. Another chimpanzee, Enos, became the first and only chimp to orbit Earth in 1961.
France contributed to the animal astronaut program in 1963 with Félicette, a cat who became the first and only feline in space, surviving her mission but later euthanized for study. In 1968, two Soviet tortoises aboard Zond 5 were the first living Earth creatures to circle the Moon and return alive.
After humans landed on the Moon in 1969, animal involvement continued in different capacities. The Apollo 17 mission carried five mice around the Moon in 1972. In 1973, spiders Arabella and Anita demonstrated that webs could be spun in microgravity aboard Skylab. More recently, microscopic tardigrades, or "water bears," in 2007 endured direct exposure to the vacuum of space.
Today, animals continue to contribute to scientific research aboard the International Space Station, participating in studies on bone loss and muscle wasting. These creatures, often identified by numbers rather than names, are considered the unsung heroes of space exploration, continuing the legacy of their predecessors who made human spaceflight possible.