The astronomical satellite Kosmos 215 was launched in April 1968 to examine ultraviolet and X-ray stellar radiation. During a period of 40 days the spectral region from 1250 Å to 2700 Å was recorded by 7 photon-counters and photomultipliers mounted in the focal planes of similar telescopes with apertures of 70 mm, fields of view 1° and focal ratios about ⅓. The optical axes of all the telescopes were parallel. The satellite was not stabilized but special damping was used to reduce the rotational velocity to 0°.12 sec−1. The optical telescopes scanned the sky and recorded all stars which crossed their fields of view.