The Interbol spacecraft were two pairs of satellites designed to measure different parts of Earth's magnetic field: one pair with orbits of 500 kilometers by 200,000 kilometers (tail probes), the other with orbits of 500 kilometers by 20,000 kilometers (auroral probes). Originally an Intercosmos project with a launch planned for the late 1980s, Interbol was delayed until 1995–1996 following the breakup of the Soviet Union. Each pair of spacecraft consists of a Russian Prognoz-M (1,250-kilogram tail probe and 1,400-kilogram auroral probe) and a Czech Magion (50 kg) satellite. Both Prognoz probes carried a variety of plasma and charged particle detectors, including Swedish, French, and Canadian instruments. The Magion subsatellites can fly in close proximity to the Prognoz or maneuver to as much as 10,000 kilometers from the mother craft.