OK-GLI
The OK-GLI (Russian: Орбитальный корабль для горизонтальных лётных испытаний, ОК-ГЛИ, romanized: Orbital'nyy korabl' dlya gorizontal'nykh lotnykh ispytaniy, lit. 'Orbital ship for horizontal flight tests'), also known as Buran Analog BTS-02 (Russian: БТС-02, Большой транспортный самолёт второй, romanized: bolshoi transportny samolyot vtoroi, lit. 'big transport aircraft, the second'), was a Soviet atmospheric test vehicle ("Buran aerodynamic analogue") of the orbital Buran spacecraft. It was constructed for the Buran programme in 1984, and was used for 25 test flights between 1985 and 1988 before being retired.