Originally identified in 1982 by US reconnaissance satellites as the 'Ram-M' single-seat high-altitude reconnaissance aircraft, and later codenamed 'Mystic' by NATO, the twin-boom straight-wing jet, currently publicised as a high-altitude research aircraft able to carry around 1500kg of sensors, is now known to exist in two versions. The first of two prototype aircraft, designated M-17 Stratosfera ('Mystic-A'), first flew in 1988 and are powered by a single 68.6kN thrust Rybinsk RD-36-51V turbojet developed from the Tu-144 SST powerplant. The M-55 Geofizika ('Mystic-B') , has two 49kN thrust Perm/Soloviev PS-30-V12 turbojets mounted side-by-side behind a raised cockpit installed in a longer nose, together with a reduced span wing.
The M-55 'Mystic-B' differs from the first M-17 Stratosfera in having a longer jetpipe, shorter engine intakes, a reprofiled nose and an undernose FLIR turret. A subsequent version of the Geofizika is twin-engined.
The role of the 'Mystic-B' is described as environmental sampling missions or high-altitude research and endurance in this role is claimed as over 4 hours loiter capability at 20000m. A further variant of the M-55 is reported to be under development with wingroot mounted engines in stalled in a conventional fuselage carrying a sweptback tail unit . Two 'Mystic-A' prototypes, followed by two 'Mystic-B' and two pre-production 'Mystic-Bs' were flying by 1992.
