Purpose of the BION-M1 project was laying the evidence and technological basis for addressing the medical issues of future remote space exploration missions by humans. The program of researches with the use of mice was focused on elicitation of cellular and molecular mechanisms of the muscular, cardiovascular and immune reactions to extended exposure in microgravity. The comprehensive studies combined lifetime measurements with investigations of mice tissues and cells by dint of the cutting-edge morphological, biochemical and molecular biology techniques. Males of mice C57/BL6 aged 4 to 5 months were chosen as the object of studies. They were distributed into the flight, ground control and two vivarium (laboratory control) groups and investigated immediately on return and after 7 days of readaptation. Some of the physiological functions were recorded throughout the flight. To ensure wellbeing of the animals in the experiments and to enhance data quality, prior to launch the mice were specially trained so as to accommodate to the group living, eating space food, and in-flight stress factors. Those of the mice that were designated for lifetime investigations were tested and received training pre-launch.