Abandoned polar radar station (Russia). Objects remote from civilization and in need of energy supply were supplied portable energy sources RTG (radioisotope thermoelectric generator), which operate on radioactive isotopes (most often on radioactive plutonium or strontium). About a thousand such devices were manufactured in the USSR, some of them were lost in transit or subsequently abandoned, decaying and contaminating with radiation environment. Such installations are now used only to provide energy. space vehicles, 2019