until 1994. Zenit variants Zenit 2 Zenit 2 was the first version to be launched in 1961 (there was no Zenit 1). The arrangement of cameras varied, but most flights carried four cameras of 1000 mm focal length, and one of 200 mm focal length. The single lower resolution camera was intended to provide low-resolution pictures that would help give a context to the high-resolution pictures. Each camera had 1500 frames of film and from , each frame held an image of a square. The ground resolution was stated to be although some unofficial sources claim it was much better—one source claims the number of cars in a car park could be counted. The cameras were developed at the Krasnogorsk Optical-Mechanical Factory near Moscow. The Krasnogorsk factory, which had been producing a variety of optical equipment for the military since 1942, was also the manufacturer of the popular Zenit SLR cameras. Zenit 2s also carried ELINT equipment called Kust-12M (bush) to receive NATO radar signals. The satellites carried a parabolic antenna, around in diameter, that is associated with this equipment. However, it is unclear if the antenna transmitted recorded signals to the ground or was for intercepting radar signals. In the latter case they would have been recorded on magnetic tape, to be retrieved after the return capsule landed. There were 81 Zenit 2 launches. 58 were successful and 11 were partially successful. There were 12 failed missions, 5 because of a satellite malfunction and 7 because of a failure in the launch vehicle. First flight – Kosmos 4, 1962. Last flight – Kosmos 344, 1970. Zenit 2M Improvements included a new camera system and the addition of solar panels. As the spacecraft mass was increased to 6300 kg, the Vostok rocket was replaced by the Voskhod rocket and Soyuz rockets. In common with Zenit 2 satellites this also had an ELINT payload. First flight – Kosmos 208, 1968. Last flight – Kosmos 1044, 1978. Zenit 4 Unlike Zenit 2, little information on Zenit 4 has been released. The Zenit 4 was intended for high-resolution photography and carried one camera of 3000 mm focal length as well as a 200 mm camera. The focal length of the main camera was greater than the diameter of the capsule so the camera made use of a mirror to fold the light path. The ground resolution is not publicly known but it is