The M-55 Geophysica is a dual turbojet aircraft designed and produced by Myasishchev Design Bureau (MDB). The aircraft can carry heavy payloads of the order of 1500 kg. M-55 can operate at the altitude up to 21 km for about 5-6 hours. The cruise ground speed is about 740 km/h. M-55 has various bays where the instruments can be installed. The main bay is longer than 5 m and very large instruments can be installed. The take-off and landing distance is less than 1000 m, but the minimum runway length required for safe operation is 2000 m. The maximum takeoff weight of 24000 kg. The M-55 is an all-weather aircraft. The aircraft can fly for long periods in cold stratosphere, as shown during the airborne polar experiment (APE) mission and performs dives from the maximum altitude down to below the tropopause. The aircraft is rugged enough to fly into strong lee wave events as occurred on January 9th, 1997. The payload may be subdivided into 2 categories: the aerosol payload and the chemical composition payload. The instruments were remote sensing and in situ types. The results of the different flights, the close spacing between one flight and the next, and the experimental flight paths, all indicate that the first APE mission was a success technically and scientifically. The Arctic mission has been a key point for any further development of the M-55 Geophysica scientific activity. Much experience has been gained on the aircraft capabilities, on instrument development and integration and in campaign management. The aircraft had never flown before in cold stratosphere and had never flown over mountain lee waves.