Since the beginning of the space age in the 1950s, animals have played a vital role in space exploration. Many creatures, both large and small, have journeyed beyond Earth’s atmosphere in the name of science and discovery.
But space travel can be perilous, and sadly, not every animal astronaut has made it back alive.
If you’re short on time, here’s a quick answer to your question: over a dozen animals are known to have died during spaceflight or training for missions. The vast majority were mice and rats used in biological research studies.
First Animal Deaths in Space
Laika the Dog
On November 3, 1957, the Soviet Union launched the first animal into orbit – a dog named Laika – on board the Sputnik 2 spacecraft. Unfortunately, Laika’s trip into space was a one-way mission. The technology to return from orbit had not yet been developed, so it was known from the beginning that Laika would not survive.
However, her death sparked debates about animal rights around the world and helped to spotlight the immense risks and challenges faced by human spaceflight in those early pioneering days of the Space Age.
Laika was a stray mongrel dog found on the streets of Moscow. Soviet scientists chose to use Moscow strays since it was assumed that such animals had already learned to endure harsh weather and hunger. This particular dog was around three years old and weighed about 13 pounds.
She was placed in intensive training for cosmic flight and adapted well to the small, cramped cabin of Sputnik 2.
Although the experiment was always designed to be fatal, Soviet scientists had planned to euthanize Laika with poisoned food after a week in space so that her death would be painless. However, due to a malfunction in the thermal control system, temperatures inside the cramped cabin rose to intolerable levels.
It is believed Laika likely died from overheating and stress just hours after reaching orbit. Only five to seven hours after launch, no further signs of life were received from the Sputnik 2 spacecraft.
While Laika’s sacrifice helped the Soviet space program achieve key milestones and intensified the competitive Space Race with the United States, her death also generated anger from animal rights groups.
The ethical debates surrounding animals in scientific research grew, and Laika later became viewed as an icon for the terrible suffering that has sometimes been inflicted on animals in the name of technological progress.
Mice and Monkeys Lost During Suborbital Launches
Laika was not the first animal to be launched into space. The United States and Soviet Union had been using animals for suborbital spaceflight tests throughout the 1940s and 1950s. These earliest animal astronauts included monkeys, dogs and mice.
In one notorious example, a V-2 rocket launched by the United States in 1948 carried a rhesus monkey named Albert to an altitude of 39 miles. Unfortunately, Albert died of suffocation during the mission.
In all of the V-2 monkey tests, none of the monkeys survived the intensive deceleration upon reentry. Several mice also perished in suborbital tests conducted on German V-2s obtained at the end of World War II, as the United States ramped up its rocket technology development.
The Soviet Union had more success with animal suborbital flights, recovering dogs like Dezik and Tsygan from their capsule after launch. However, not all animals survived these early crude missions. For example, Soviet scientists launched mice towards the upper atmosphere on R-1 rockets in 1951, but radiation exposure was too high for anything to survive at that altitude at the time.
It took extensive trial and error with animal test subjects before technology advanced enough to bring humans above the dense atmosphere and reach outer space. While tragic, these animal missions served an instrumental role in pushing forward our understanding of rocketry and physiologic response during spaceflight.
Animal Mortality Rates in Orbit
High Losses During Early Scientific Missions
In the early days of spaceflight, high mortality rates were common among animals launched into orbit. Scientists were just beginning to understand the impacts of microgravity, radiation exposure, and other hazards of the space environment.
Tragically, many animals sacrificed their lives to advance this research.
The first animals intentionally sent into space were fruit flies aboard a U.S.-launched V-2 rocket in 1947. The rocket reached only a suborbital altitude, but the flies’ survival proved living organisms could withstand the launch and return to Earth. Of mice launched to higher altitudes in 1950, only about half survived the journey.
The Soviet space program launched the first animals into orbit – dogs Belka and Strelka in 1960. Fortunately, they survived and were the first Earth creatures recovered alive from spaceflight. But not all dogs were so lucky. In one disastrous mission that same year, a spacebound canine died when the rocket exploded after launch.
Even the United States’ most famous spacefaring chimp, Ham, had close calls with tragedy. A predecessor named Able perished after a rocket failure in 1959. Ham’s own 1961 Mercury mission experienced multiple malfunctions, which could have doomed the astrochimp if mission control had not acted quickly.
Improved Survival in Later Programs
As space agencies gained experience with animal launches over time, survival rates markedly improved. For instance, of 5 mice launched aboard NASA’s final Biosatellite mission in 1969, 4 returned unharmed.
The Soviet Vostok 5 in 1963 became the first multi-animal mission, launching two dogs and two rats. Thanks to added redundancies and safeguards, all passengers survived reentry and recovery. Later Vostok dogs like Veterok and Ugolyok had 100% survival odds during their day-long orbits.
By the late 1960s, animals launched by both the U.S. and U.S.S.R. routinely experienced survival rates over 90%. Standardized life support systems, rigorous preflight training regimens, and streamlined recovery operations all contributed to better outcomes compared to earlier deadly missions.
Today, animals are rarely sent into space, as most biological research has shifted to orbital laboratories like the International Space Station. But for those intrepid astro-animals who paved the way in the pioneering era of spaceflight, survival was far from guaranteed.
Modern astronauts owe a great debt to the sacrifices of their non-human predecessors.
Training Accidents on Earth
Chimpanzee Drownings
In the early days of the space program, chimpanzees were viewed as ideal test subjects due to their intelligence and anatomy similar to humans. However, there were several tragic accidents involving chimps during training on Earth.
In one incident, a chimpanzee named Ham drowned during a water escape training exercise prior to his historic suborbital spaceflight in 1961. Despite efforts to rescue him from the water tank, Ham sadly perished.
There were other instances where chimps met an untimely end during training. A chimp named Bonny was killed when a mechanical failure caused her ejection seat to fire on the ground in 1956. Another chimp, Moja, died when his restraint harness came undone during an ejection seat test in 1958, causing him to crash into the interior of the capsule.[1]
These tragic accidents highlighted the dangers of spaceflight, even during preparation on Earth. Out of the dozens of chimpanzees trained by NASA and the Air Force, few actually made it to space successfully.
Though unfortunate, the sacrifices of those that perished advanced understanding and pushed space technology forward so humans could eventually venture into the cosmos.
Other Fatal Mishaps
Chimpanzees were not the only animals that experienced training accidents with fatal outcomes. Monkeys, mice, rabbits, and dogs also lost their lives in the name of spaceflight research on Earth.
In one disturbing incident, four rhesus monkeys suffocated when their capsule simulator lost pressure and descended too rapidly from high altitude in 1958.[2] Another time, two monkeys named Alberts I and II died when their rockets exploded shortly after launch in 1948.[3]
Dogs met an unfortunate demise as well, like Laika who died of overheating aboard Sputnik II in 1957 since there was no way to return her to Earth. And eleven mice died when their Discoverer VIII satellite recovery system failed in 1960.
These examples illustrate the immense risks involved in early space experiments even during test runs on Earth. Animal test pilots encountered numerous technical glitches, accidents, explosions, and malfunctions that cost them their lives.
The march toward manned spaceflight necessarily involved sacrifice and tragic loss.
Ethical Concerns and Commemorations
Questioning Animal Experimentation
The ethics of sending animals into space has been debated since the beginning of the space age. While these animal astronauts have been crucial for understanding the impacts of spaceflight, their treatment and untimely deaths have caused some to question the morality of animal experimentation.
According to records, over a dozen dogs and several dozen monkeys and mice have lost their lives while serving as test subjects in space programs worldwide since the late 1940s.
Those opposed argue that consent cannot be obtained from animals and that intentionally putting their lives at risk purely for scientific curiosity is inhumane. A shocking 17 out of 18 rhesus macaque monkeys sent on one early NASA mission died either during flight or soon after landing, causing outrage from animal welfare groups.
Some label animals being shot into orbit in cramped capsules with limited life support as exploitation and even murder. The morality is further questioned considering the substantial suffering most of these creatures endured during training and spaceflight.
However, without animal testing, experts argue it would have been impossible in those early years to determine the safety of spaceflight for humans. Mice, monkeys, chimpanzees and dogs helped prove the immense stresses space travel placed on living organisms before people were risked.
Modern experiments on animals in orbit continue to expand our knowledge of microgravity, radiation, longevity and more, often benefitting both human and veterinary medicine. Still, commemoration events help ensure these animals’ sacrifices are not forgotten.
Memorials and Tributes
To honor the animals that paved the way in space discovery, various tributes, artworks and memorials have been erected internationally. For instance, near NASA’s Langley Facility in Hampton, Virginia stands a series of commemorative moon tree plantings grown from seeds that flew aboard Apollo 14 in 1971.
Their branches spread in honor of the lives lost for lunar advancement. Additionally, a prominent 117 foot titanium statue was constructed in Moscow in 1964 to pay respect to Laika and all those who enabled human spaceflight.
It portrays a rocket heading sky bound, the exhaust flames forming figurines reaching for the cosmos.
Other thoughtful memorials exist too, like small monuments at Russian and American training and launch facilities honoring specific dogs and primates who perished during specific pioneering missions. For example, a pair of sculptures remembering two heroic Moscow street dogs named Belka and Strelka who miraculously survived an early 24 hour orbiting flight were later erected where their capsule landed.
The two global superpowers have learned from each other’s tragic mistakes and now implement strict ethical guidelines restricting animal testing projects to only essential, humane and non-lethal studies.
While animals in space tributes commemorate the past, experts agree continual progress safeguarding test subject welfare is still required. With glory comes responsibility. Though mistakes will likely happen in pioneering endeavors, proper commemoration keeps public awareness open that the lives lost, whether monkey or man, shall not be in vain.
In memoriam, their place in spacefaring history is secured, having laid down the ultimate sacrifice to propel our species forward into the cosmos.
Conclusion
While animal astronauts have given their lives in the advancement of technology and knowledge, efforts have been made to reduce casualties in recent decades. Their contributions paved the way for humans in space. The brave monkeys, dogs, mice and more who perished will not be forgotten.
