Animal Testing in Space

Ethan Wong

March 31, 2023 (updated June 5th, 2024)

*Disclaimer: Listed under favorite articles because I found it super interesting to learn about (i.e. fruit flies and mice)*
Throughout the 1950s and into the 1960s, many space companies participated in sending animals like dogs and monkeys into space to test the unknown environment that would later be a destination for humans. This cruel and barbaric experiment usually led to quick demise for many of the creatures launched aboard rockets, yet their sacrifice was a major factor in the development of human-space interaction and exploration. 

One of the more famous experiments done on animals in space was done by a chimpanzee named Ham. The use of chimps to test the conditions and exposure of space travel had several reasons that were upheld by NASA; for instance, humans and chimpanzees have around the same reaction speed when their bodies are triggered by physical stimuli. In order to confirm that levers would be operated in the same manner in space as on Earth, scientists trained chimps on working with different procedures. Using light and sound, the animals were fed with banana scraps when successfully pulling/pushing levers and often placed in simulations to get them familiar with altered gravity. On January 31st, 1961, Ham became the first chimp to exit Earth’s atmosphere, traveling at over 8500 miles per hour. He flew aboard a Mercury capsule which was lifted with the help of a Mercury-Redstone rocket. According to NASA, Ham ended up spending 16 minutes in the air before he descended over 157 miles from his maximum altitude to land in the Atlantic Ocean. After being rescued from a recovery boat, his capsule was opened to reveal a relatively healthy chimp, who survived the flight with only a few mild injuries. He then continued to spend the rest of his life in a zoo. Ham involuntarily helped pave the road for the first American to enter space, Alan Shepard, later that year. 

Meanwhile, the Soviet Union was taking more interest in using dogs to test their upcoming mission. Out of many dogs the Soviet Union used, at least 5 dogs were killed in space testing according to Wired. One of the dogs was Laika, who took a mission aboard a Sputnik rocket into space. Her mission was later uncovered as a suicide mission, as the capsule had no capability of landing on Earth safely. She lifted off from Earth on November 2nd, 1957, and reached orbit, yet scientists estimate she died shortly after due to extreme temperatures, as the heat shield had gotten damaged. When Sputnik-2 returned to descent, it burned up in the Earth’s atmosphere along with Laika, where her remains could not be recovered. A statue was later built to memorialize her sacrifice.

While chimps and dogs are giant creatures, super small animals were also used in the future to test the conditions of space. Fruit flies are similar to humans being model organisms, and are susceptible to many of the same diseases that humans can catch, making experimentation with these bugs compelling. For instance, one research experiment tested the immune systems of both healthy fruit flies and fruit flies with heart dysfunctions in microgravity. The fast reproduction rate of these creatures allows scientists to quickly understand the potential influence of an altered environment on humans’ immune system, metabolism rate, heart condition, etc.

Mice have also been used to test conditions in space, yet more recent experimentations have resulted in the safe return of the animals. In 2019, mice were sent up to the ISS as an experiment for the causes of muscle-bone loss due to the unusual gravity in space. Around 40 mice were sent through a Falcon 9 Dragon rocket to the space station where they were studied. The study consisted of a control group of mice on Earth, as gravity doesn’t allow such muscle loss to take place. Up in the ISS, some mice would be injected with drugs to stop the myostatin that would typically regulate bone mass. The discoveries stemming from this experiment will help pave the way for understanding bone and muscle loss in space, which will assist astronauts in their future journey to Mars, where exercising daily will not be accessible. 

Although countless animals involuntarily gave their lives away for space experiments, they were able to bring back countless amounts of data and information about the effects of space. These brave animals sacrificed their lives to do something which humans could have never accomplished alone–testing the extreme dangers of space flight whilst preserving the life of humans. Most of these animals were forced to give up their lives for the benefit of space exploration, and the advancements humanity has achieved in space would not have been possible without them.