The Soviet Union authorized Energia-Buran as a reusable heavy-payload system. A family of structural, aerodynamic, systems, and flight articles supported development, while selected test pilots and cosmonauts prepared for later crewed missions.

OK-GLI carried pilots on 24 atmospheric flights from 1985 to 1988. Its jet engines allowed independent takeoff, after which crews practiced the steep approach and progressively more automatic landing profiles required by the orbital vehicle.

Orbiter 1.01 launched without a crew on November 15, 1988, completed two orbits, and landed automatically at Baikonur. The program ended before a second orbital or first crewed mission could fly.