Fun facts: Development of the MiG-25's replacement began with the Ye-155MP (Russian: Е-155МП) prototype, which first flew on 16 September 1975.Although it bore a superficial resemblance to the MiG-25, it had a longer fuselage to accommodate the radar operator's cockpit, and was in many respects a new design. An important development was the MiG-31's advanced radar, capable of both look-up and look-down/shoot-down engagement, as well as multiple target tracking. This gave the Soviet Union an interceptor with the capability to engage the most likely Western intruders (low-flying cruise missiles and bombers) at long range. The MiG-31 replaced the Tu-128 as the Soviet Union's dedicated long-range interceptor, with far more advanced sensors and weapons, while its range is almost double that of the MiG-25.
