Cargo Transport Container
For cargo missions the orbiter would have been replaced by a so-called Cargo Transport Container (GTK or 14S70) that could house a variety of payloads. This configuration was known as Buran-T (T standing for “transport”) before the name Energiya was adopted in 1987. The interfaces between the rocket and the payload would have been virtually identical to those on Energiya-Buran. Two diameters were considered for the GTK—namely, 5.5 m and 6.7 m—with the final choice falling on the latter, which turned out to be the most favorable in terms of aerodynamic and other characteristics. The container was 42 m long and had an internal volume of about 1,000 m3. The two main sections of the container were to be jettisoned after the rocket passed through the thickest layers of the atmosphere. The GTK was not used on the maiden flight of Energiya with the Skif-DM/Polyus payload, which flew the launch profile unprotected, except for a shroud on the upper FSB section. Strictly speaking, this was not a standard Buran-T configuration .