Two Rhesus monkeys were flown into orbit implanted with sensors to permit monitoring of carotid arteryblood flow. Additionally eighteen pregnant white rats were sent to be used for studies of the effects of microgravity and radiation. The rats subsequently produced normal litters. The mission concluded after five days. This was the first time the Soviet space agency flew monkeys in space, coming 34 years after the U.S. first put a monkey into space, and 22 years after the Soviet Union started putting humans into space. The mission differed markedly from earlier Cosmos flights, both in terms of Soviet scientific goals and in the degree of cooperation required between the United States and the USSR. The two countries had to interact at a high level to integrate U.S. experiment hardware with the Soviet spacecraft and instrumentation systems. Experiments focused on the effect of weightlessness on various physiological parameters. A study of circadian rhythms was concerned with the synchronization of primate motor activity, body temperature and skin temperature rhythms to a fixed light/dark cycle and to each other. Blood pressure and flow were monitored to evaluate short and long-term changes in these parameters. Changes in calcium metabolism were studied to help determine the effect of weightlessness on the skeleton. The two rhesus monkeys flown on board were about three years of age and each weighed approximately 4 kilograms. Height was a constraint in selecting animals for flight. This was because a Soviet vestibule experiment required that the flight restraint couches oscillate vertically within the animal capsules. The monkeys were conditioned to sit in the restraint couches and perform tasks for food rewards. Tasks included pressing a lever with their feet and tracking a moving light with their eyes. Monkeys were also trained to eat and drink from food and juice dispensers. The monkeys in both the flight and control groups were implanted with blood pressure, flow cuffs, and other sensors to measure several physiological parameters. An experiment was conducted to investigate space flight effects on the sensory development of the rats that spent part of their prenatal gestation period in space. Ten pregnant female Wistar rats were flown. Ground control groups contained the same number of rats. At the start of the flight or control experiments, the rats were at gestation day 13 of their 21-day cycle.
