COSMOS 1689, also known as Kosmos-1689, is an Earth Observation satellite launched on October 3, 1985, from the TYSMC launch site using a Vostok 8A92M vehicle from LC31. The satellite was manufactured by VNIEM and belongs to the Resurs-O series with the SP-1 bus configuration. It has dimensions of 6.4 meters in length, 1.4 meters in diameter, and spans 11.6 meters when deployed. The dry mass is 1900 kg, identical to its launch mass. Equipped with two types of equipment sets (MSU-E (2), MSU-SK, MSU-S for the first set; MSU-E (2), MSU-SK for the second), it uses two deployable solar arrays and batteries for power. The satellite's shape is described as cylindrical with two panels. It was owned by PRIR and operated under the Resurs-O1 No. 1L payload mission, designed for Earth Observation purposes.