Development and Enlistment: The MiG-31 was developed to replace the MiG-25 Foxbat and serve as a heavy fast fighter, capable of counterattack and air space surveillance. It entered the military in 1981.Technical characteristics: MiG-31 has a maximum speed of nearly 3 Mach (about 3,700 km/h), with a wide range and fast acceleration. It is equipped with a powerful radar system and various missiles and ballistic missiles.Mission: The MiG-31 is used for a variety of missions, including protecting the nation's airspace, airspace surveillance, and supporting other military operations.Upgrades: Upgraded versions of the MiG-31 have been developed throughout the years, including the MiG-31BM with improved radar and electronic systems, as well as the ability to carry a range of new weapons .International Use: In addition to the Soviet Union and Russia, the MiG-31 has also been exported to several other countries, including Kazakhstan and Syria. Some other countries such as Belarus and Uzbekistan still own these aircraft.