Spaceflight Now reports that a Soyuz rocket launch yesterday was used to place a Kobalt M reconnaissance satellite into orbit. The classified military earth observation satellite is said to carry a camera that returns film to earth after its several-month mission.
Similar film-based technology was used in the U.S.-based Corona reconnaissance satellites that were run by the Central Intelligence Agency from 1959 through 1972. A decided limitation of these systems is the delayed intelligence where months go by before the film can be captured and processed, and a high failure rate. Of the 144 Corona satellites launched, only 102 returned usable images.
Russia has a long history of film-based earth observation satellites, with more than 700 launched since 1961. Kobalt satellites are said to obtain a 0.95 meter ground resolution image. While the satellite is deemed classified, the imagery is commercially available through Eastview and Terraserver.
I was surprised to learn that film-based cameras are still being deployed on satellites, given today’s high-resolution digital sensors in use in the commercial remote sensing industry. Russia has deployed satellites with optical and radar sensors for large-scale earth observation projects with signals relayed to earth, but their resolution was on the order of a kilometer to 137 meters with swaths of hundreds of kilometers in width.