From launching Sputnik 1 into space in 1957 to planning human settlements on the red planet by 2050, we have come a long way.
Since the 18th century, space agencies have launched a variety of animals into the space to study the survivability of the spacecraft as well as the effects of space on these animals. Many animals gave their lives for these space experiments so that we can plan our next step to explore the depths of mysterious space and to find our next home in this far-flung universe. Here is a list of few animals who have successfully contributed to the scientific experiments of animals in space.
On 23rd September 2014, SpaceX CRS-4 followed a four-day transit to transport 20 mice to ISS to study microgravity and its long term effects on rodents.
RR-1 (Rodent Research – 1) was a joint operation between CASIS and NASA, and it lasted 37 days. It was noticed that there was not much difference in the behavior shown by the mice in the “weightlessness” of the microgravity environment than the mice on the Earth. The mice were showing species-specific behavior throughout the study. Younger mice showed a greater level of physical activity as compared to the older mice. However, after 10-11 days, younger mice exhibited unique “race-tracking behavior. All the mice remained completely active and healthy throughout the study . After the completion of study , tissue samples of first 10 mice from CASIS investigation were sent back to the Earth on Oct 25 through SpaceX Dragon Spacecraft and tissue samples from remaining 10 mice were sent back to the earth in second Dragon spacecraft on January 2015. NASA examined spleen and liver samples from both earth and space controlled mice to study the quality of RNA , gene metabolism and expression and measurements of protein content. Later , the results were transferred to Human Health Research where they used the results to facilitate new treatments for bone and muscle related diseases.
After 1969’s first manned moon mission, scientists again planned to study the effects of microgravity on animals. Two garden spiders Arabella and Anita were used in another space experiment in 1973 to see if they can spin webs in space. The experiment was proposed by Massachusetts high school student Judith Miles and was called “web formation in zero gravity.” The study revealed a lot about the effects of microgravity on the motor response. The spiders were still able to spin webs, although they were finer than the ordinary web. They sensed their weight to determine the required thickness of the web. They survived 1 year after returning back to Earth but unfortunately both Arabella and Anita died on Skylab ; United States’ first space station in 1973. Later , NASA donated these 8 legged astronauts to Smithsonian’s National Air and Space Museum for display.
After astronauts, it was aquanauts who reached the International Space Station for another space study. In 2012 Japanese space agency sent a fish to ISS, and it was a Medaka with clearly transparent skin, which made it easier for researchers to study what’s going on inside the fish. The aquarium in which they were sent had LED lights to differentiate day and night, a water circulation system, and an automated feeding system—the experiment aimed to study the degradation of bones, muscle wastage, and impact of radiation on the fish. The fish swam in a position similar to upright on Earth, and there was no sense of up or down. Also fish started losing its bone density right after arriving in the orbit. They were later preserved and the specimens were sent back to the Earth for researchers to examine. Rest of the fishes were frozen, said astronaut Chris Hadfield .
Tardigrades, also known as water bears or moss piglets, are the first animals to survive in outer space. They are microscopic invertebrates which means they lack a backbone. They eat fluids, as weird as it sounds. In 2007, European researchers sent tardigrades into space to test how far they can survive. They were kept dehydrated and were exposed to low Earth orbit for ten days, after which they were sent back to the Earth. The researchers then rehydrated them. Most of the water bears successfully revived and started producing viable offspring. This is the first lifeform on Earth out of the discovered life forms that have shown extreme levels of survival and adaptability. Radiation, lack of oxygen, dehydration; nothing affects tardigrades. This is one of the major reasons that people believe that they must have originated off Earth.
5. Pavement Ants
After sending all these animals to space, the next nominee for the “Animals in space” experiments were Pavement Ants. Scientists were interested in studying the effects of microgravity and Earth gravity on these ants. In January 2014, ants were sent aloft through a supply rocket to the ISS. They sent 80 colonies of pavement ants in transparent plastic boxes in which there was a nesting area inside every box. The ants were kept in ambient temperature between 21 – 24°C while on ISS and during their transport to ISS. The pattern of experiments was kept similar both on earth and in space settings. The experiment started after 12 days of onboarding ants and during these 12 days some ants died both on earth and ISS settings fot the experiment. So, when the experiment started there were already some dead ants in the nest area. During the experiment, the barriers were removed, exposing the ants to a larger area. They noticed that ants were struggling to hold onto the ground, which made them move much slower than those on the Earth and also reduced the interaction between them, further reducing cooperation as they were just floating around for 7-8 seconds straight. The insects couldn’t respond well to microgravity , they lost the perception of ‘ Exploration ‘. 5-25 ants died on ground setting while the no. of dead ants on ISS was 5-12.
6. Butterfly larvae
Bioserve Technologies and the University of Kansas sent some Painted lady and Monarch butterfly larvae to the international space station through STS- 129 shuttle mission to study their ability to develop and grow on being exposed to microgravity. Vanessa cardui ( known as the Painted Lady butterfly) larvae were six days old. Danaus plexippus ( known as the Monarch butterfly) larvae were in the 4th instar development stage during the launch. After seven days, both these larvae started to pupate (pupa stage) and remained in the cocoon stage for 7 to 10 days. Finally, on 30th November, butterflies emerged. However, these creatures failed to fly in low gravity conditions and kept banging in the plastic cages. The Monarch butterflies were only expected to survive 4 days while the Painted lady butterflies were expected to survive up to one week as told by NASA officials . However , no updates were shared after that.
In January 2015, some amputated flatworms and whole flatworms were sent to ISS by SpaceX Commercial Resupply Service Mission 5. The experiment lasted nearly five weeks, and this experiment aimed to study the effect of the space environment on tissue regeneration. The pharynx fragment ( a worm whose tail and the head is removed ) surprisingly grew a second mouth and two heads. Also, the whole flatworms split into two different worms where a second worm grew attached to the tail of the first worm and split eventually. This is a type of asexual reproduction, and scientists believe that this might result from spontaneous fission. They had a difficult time adjusting to normal living conditions when brought back to Earth. Two-headed worms again regenerated two heads on Earth after researchers removed it and refused to return to normal life. More study is needed to figure out why this happens.