Radiobiological experiment aboard the biosatellite Cosmos-690.

In 1974, the USSR launched the biosatellite Cosmos-690 equipped with a gamma-irradiation unit that carried 35 rats. On the 10th flight day, the rats were exposed to radiation at doses of 220 or 800 rads. During the subsequent 10 d, radiation injury developed in a space environment. Similar ground-based experiments were carried out to simulate space flight environment effects. The results obtained were studied on a comparative basis. The conclusion is made that effects of a short-term space flight, as long as 20 d, do not essentially modify the radiobiological effect.