The Resurs-F1 (17F40) was one of three subseries of the Soviet Resurs-F1 film-return earth observation satellite family. They were a follow-on to the Fram (Zenit-4MKT) series.
The Resurs-F1 satellites were based on the Zenit-4 reconnaisance satellites. They featured a Zenit/Vostok type 2.3 m spherical reentry capsule, which housed the cameras and film, a service module and a orbital maneuvering module. It was battery powered allowing for 14 days of operations, although up to 10 days on stand-by could be added. The differences between the 17F40, 17F41 and 17F43 versions is not clear.
The Priroda-4 imaging system consisted of a three channel multispectral system that includes two KFA-1000 cameras and three KATE-200 cameras.
The KFA-1000 (SA-20M) cameras with 1000 mm focal lenght provided stereo images of up to 5 m resolution with a 60 km swath width. It had a capacity of 1800 frames.
The KATE-200 (SA-34) camera with 1000 mm focal lenght provided for Earth survey in three spectral bands. It could collect stereoscopic imagery having an along-track overlap of 20, 60, or 80 percent. Resolution of the images, according to spectral band and survey altitude, varied from 10 to 30 m over a 180 km swath width. One of these cameras was coupled with a SA-33 stellar indexing camera for exact geolocation. The KATE-200 had a capacity of 1200 frames, each 180 mm by 180 mm.
All film frames of both systems were marked with codes to record camera parameters, including camera and frame number, film number, focal length, and timing codes.
