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Bob's Primary Responsibilities

Canadian Space Agency astronaut Bob Thirsk was uniquely qualified for this mission. A bio-medical engineer and a medical doctor, his knowledge and expertise reached into many areas, notably in the physiological adaptations that occur in weightlessness as well as in microgravity experimentation relating to materials processing and fluid physics.

Since 1983, when he was selected to become an astronaut, Bob Thirsk has accumulated 16 years of operational experience. He first trained as back-up Payload Specialist to Marc Garneau for Mission 41-G in October 1984. He was an investigator for three experiments that flew on previous Spacelab missions and was an alternate Payload Specialist on the IML-1 Mission.

One of the most common physiological changes astronauts must live with in a weightless environment is the redistribution of body fluids which can cause discomfort or problems in space or upon returning to Earth. Dr. Thirsk was leader of an international team investigating this shift of body fluids in weightlessness and its effects on the body's venous system. He has designed an experimental "antigravity suit", a pressure suit he believes will help astronauts readapt back to life on Earth.

During STS-78, Bob Thirsk participated in a number of experiments in life and microgravity sciences. Like the other six astronauts, he was both subject and researcher for several life sciences investigations. He had a major role in Canada's Torso Rotation Experiment (TRE), designed by McGill University and sponsored by the Canadian Space Agency. TRE related eye/head/body movements to the symptoms of motion sickness that many astronauts experience. Dr. Thirsk was also involved in four muscle physiology experiments. Studies on previous missions have revealed a loss of muscle mass, biochemical changes in the muscle that oppose gravity, and changes in the performance of certain muscle groups that bear weight and support the skeleton.

Dr. Thirsk was both subject and researcher for these investigations. He had a strong interest in the lung function experiment whose goal was to explain the large differences in the ventilation and the perfusion (blood flow) to the top and bottom of the lung.

Bob Thirsk also participated in one microgravity science experiment, the Protein Crystallization Facility Experiment. The astronauts crystallized large proteins (such as DNA, RNA or viruses) that were analysed back on Earth. The goal was to better understand the interactions within and between proteins, and eventually, to design better drugs to inhibit or improve certain effects.

Dr. Thirsk performed two separate sets of experiments on behalf of the Young Space Scientists Program (YSSP). The first set of experiment were the winners of a nationwide YSSP space science contest developed by two young Canadian research teams. The second component of the YSSP program on this mission was a set of four generic experiments designed to allow all Canadian students to participate in the space science experience. The four generic experiments included: Canolab, a Canadian seeds experiment designed for elementary students; Radiation detection, a visual experiment in the detection and measurement of space radiation for high school students; Height measurement, an investigation into the effects of gravity and spaceflight on astronaut musculoskeletal system, which involved the measurement of astronaut height before and during the mission; and Hockey Puck Physics, an experiment, which resulted in the production of an educationalz video for high school students, demonstrating the principles of Newtonian physics with a Canadian twist!