COSMOS 1783 (also known as Kosmos-1783) is an early warning satellite launched by the Soviet Union on October 3, 1986, from Plesetsk Cosmodrome using a Molniya 8K78M launch vehicle. The spacecraft has dimensions of 4 meters in length and 2 meters in diameter with a span of 5 meters. It has a dry mass of 1150 kilograms and weighed 1250 kilograms at launch. Equipped with two deployable fixed solar arrays and batteries for power, the satellite is part of the Oko early warning system operated by PVO. Manufactured by NPO Lavochkin (NPOL/KOMET), its shape consists of a cylinder plus two panels and has an RCS value of 9.0832 square meters. The payload includes an Oko 73D6 No. 6037 sensor for early warning purposes.