Magion 1 was a czechoslovakian subsatellite that separated from Intercosmos 18 on
14 November 1978. It was magnetically stabilized and was designed to carry
ionospheric-type experiments related to the International Magnetospheric Study. MAGION had
a prismatic shape (0.3 × 0.3 × 0.15 m) and followed the orbit of Interkosmos 18. Czechoslovak participation in studies of
mutual relations between the earth's magnetosphere and ionosphere consisted mainly of
measuring VLF phenomena on board MAGION, which was moving slowly away from Intercosmos 18, and in cooperating in the measurements of
plasma properties in the vicinity of this satellite.