The second phase of the research involved animal flights in pressurized cabins of single-stage R-2 and R-5 geophysical rockets to altitudes of 200-450 km. Dogs weighing 5-7 kg were chosen as experimental animals. The animals' pulse, blood pressure, and respiration were recorded, and their electrocardiograms were recorded. The dogs were filmed continuously throughout the flight.
Between 1948 and 1961, the USSR prepared and conducted 29 launches of geophysical rockets, and carried out flights of two artificial Earth satellites and four satellite spacecraft.
Five animals that flew to an altitude of 110 km were observed over a number of years. Neither their behavior, body weight, nor fur coloration changed significantly.