Animals

In the early days of space travel, scientists wanted to ensure that animals could survive spaceflight before they attempted to send humans. During these first animal flights, scientists were able to test how a living organism would react to the unique environment of spaceflight—including such factors as cosmic radiation, the high rate of acceleration during the flight, and the effects of reduced gravity, also known as microgravity, on the body's cells and vital organs (e.g., the heart and lungs). The evaluation of animals in space also gave scientists information on how the brain would behave in microgravity.

Dogs Lead the Way

The first animal was launched from the Holloman Air Force Base in New Mexico on June 14, 1949. Albert 2 was a monkey, and he traveled 134 kilometers (83 miles) above Earth in a V-2 rocket. His heart rate, blood pressure, and respiratory rate were analyzed, but he died on his way back to Earth when the rocket's parachute failed to open. The first successful live-animal spaceflight happened on September 20, 1951, when the Soviet Union sent a monkey and eleven mice into space and back in a rocket. Then on November 3, 1957, the Soviets sent a dog named Laika in a special animal compartment on Sputnik 2. Laika became the first animal to orbit Earth, although she died after four days in space.

On August 19, 1960, the Russians sent up two dogs, Strelka and Belk, on Sputnik 5. These two animals survived fifteen orbits, returned to Earth, and later gave birth to litters of healthy puppies. The following year, two Soviet missions, Sputniks 9 and 10, each carried dogs that survived the flight and returned home. After these and other successful dog flights, scientists began sending monkeys and chimpanzees, because their bodies most closely resembled the human body. These missions paved the way for human space travel because they proved that vital organs, such as the brain, heart, and lungs, could function in microgravity.

The Neurolab Shuttle Mission: How the Brain Works in Space

In April 1998, animals played an important role on the Neurolab mission aboard space shuttle flight STS-90. This mission was dedicated to studying the effects of weightlessness or microgravity and other aspects of the space environment on the nervous system. Researchers were interested in how microgravity affects an animal's sensory systems. Signals from the sensory systems relate to balance, vision, and muscle movement and allow an animal to maintain stable vision, posture, coordination, and motion. A variety of species were on Neurolab, including rats, mice, swordtail fish, toadfish, crickets, and snails. Such experiments help scientists develop computer models so they can study how living organisms change while in space, including how their development and growth are affected. Studies on the brains, bones, muscles, and hearts of animals in space help scientists keep track of the effects that the space environment has on humans.

NASA Pulls Out of Bion Mission

In the United States, animals used by the National Aeronautics and Space Administration (NASA) are protected under regulations outlined in the "Principles for the Ethical Care and Use of Animals." In the mid-1990s, NASA was criticized by animal rights activists for participating in the Bion 11 and Bion 12 missions. The Bion programs were cooperative ventures between the United States, Russia, and France, and were intended to study the effects of low gravity and space radiation on primates such as monkeys. Activists claimed, however, that these studies were unnecessary because humans were already safely spending extended periods of time in space.

In December 1996, the Bion 11 satellite sent two rhesus monkeys into space, and they returned to Earth safely two weeks later. But the day after their return, one of the monkeys died after it had an adverse reaction to anesthesia when researchers where trying to surgically remove bone and muscle tissue samples. The second monkey also had an adverse reaction, although it survived. The Bion missions were the first that involved placing animals under anesthesia immediately upon returning to Earth after spending extended periods of time in a low-gravity atmosphere.

NASA investigated the Bion mission and determined that the monkeys were at a great risk when exposed to the anesthesia so soon after returning to Earth. Because of this risk, NASA declared that the United States would not participate in Bion 12 or any other future Bion missions.

SEE ALSO LIFE SUPPORT (VOLUME 3); PRIMATE, NON-HUMAN (VOLUME 3).

Julie L. McDowell

Bibliography

National Research Council. Space Science Board. Human Factors in Long-Duration Spaceflight. Washington, DC: National Academy of Sciences, 1972.

Internet Resources

The Brain in Space: A Teacher's Guide with Activities in Neuroscience. National Aeronautics and Space Administration. <http://spacelink.nasa.gov/Instructional.Materials/Curriculum.Support/Life.Science/Biology/The.Brain.in.Space/index.html>.

"NASA Suspends Future Participation in Bion Missions." American Society for Gravitational and Space Biology. <http://www.asgsb.org/newsletter/v13_2/bion.html>.