The most notable among design solutions is stage I. In compliance with the technical assignment, The Energia-Buran Space System should be reusable and employed no less than in 10 missions. As a result of comprehensive studies, a parachute rocket system was selected for the core stage recovery after its separation from LV. To return and reuse the core stage was a complex scientific-engineering task assumed to be solved successfully, as experimental development was progressing. Stages A to be subjected to flight tests within the LV were not provided with recovery capabilities and only certain systems were used for recovery verification.
An important factor having bearing upon the implementation of the stage A development program was that a medium-lift launch vehicle "Zenit" was being designed at Design Office "Yuzhnoye" (Dnepropetrovsk, V. F. Utkin - Designer General) in parallel with NPO Energia's work on LV Energia. Rocket stages of both launch vehicles had to be standardized at the most. It was assumed to standardize dimensions of fuel tanks, structure materials, the engine, and the majority of automatics. That the development of LV "Zenit" was in advance gave the ability to consider to a great extent results of ground and flight tests of "Zenit" LV stage I in designing stage A. A modular part of stage A was made at the "Yuzhmash" plant (Dnepropetrovsk, L. D. Kuchma - the Director). At the Experimental Machine Building Plant the aft and fore compartments have been made and stages A have been assembled (Kaliningrad, Moscow region, A. A. Borisenko - the Director).
To make the LV Energia stage II (core stage TS) was the most difficult task. Huge dimensions, plenty of piping, welded joints, cabling, and equipment resulted in that a 1.5-year production cycle was required. The Kuibyshev plant "Progress" was selected a prime contractor to manufacture the core stage and assemble LV Energia. Large compartments of the core stage were transported from the manufacturer to the launch site on a specially modified airplane 3M-T for final assembly.