The Magion experiment - A study of magnetosphere-ionosphere phenomena with a small subsatellite accompanying the parent body

The Magion (978-099C) subsatellite was launched as part of the Interkosmos 18 equipment and separated from the parent spacecraft on Nov. 14, 1978. A study of the space structure of ELF-VLF phenomena using simultaneous measurements from the two near-space satellites was performed. The Magion satellite is prism-shaped with dimensions of 300 x 300 x 160 mm and a weight of 14.56 kg; it is equipped with 137.15 MHz and 400.57 MHz telemetry, a 24-command, 149-MHz band telecommand link, power and housekeeping systems, and magnetic field stabilization. The initial orbital perigee, apogee, and inclination of the satellites were 406 km, 764 km, and 82.97 deg, respectively. Results of the parallel satellite observations were used to solve problems concerning the propagation of whistler-type waves through the ionosphere. Noise intensity data on frequencies of 800 and 450 Hz were used to verify the relatively long-term stability of emissions in the plasmapause region. The outer latitudinal boundary of the zone of possible VLF-wave propagation was determined in cases of high whistler activity.