A test bed for the RLA first stage

The RLA concept fitted well in a new philosophy to replace the existing fleet of Soviet launch vehicles by a new generation of rockets. By the early 1970s the Soviet Union was operating five basic types of fundamentally different launch vehicles each derived from a specific intermediate or intercontinental ballistic missile: the Kosmos and Tsiklon rockets (based on the R-12, R-14, and R-36 missiles of the Yangel bureau), the Vostok/Soyuz family (based on the R-7 missile of the Korolyov bureau) and the Proton (based on the UR-500 missile of the Chelomey bureau). While the R-7 based rockets used LOX/kerosene as propellants, all the others relied on storable hypergolic propellants.

Around the turn of the decade plans were being drawn up for new generations of satellites with more complex on-board equipment and longer lifetimes, requiring the use of heavier, more capable launch vehicles. By early 1973 a research program called Poisk (“Search”), conducted by the Ministry of Defense’s main space R&D institute (TsNII-50), had concluded that future satellites should be divided into four classes: “light” satellites up to 3 tons, “medium-weight” satellites up to 10-12 tons, “heavy” satellites (up to 30-35 tons), and “super-heavy” satellites (not specified). The last three classes were not served by the existing launch vehicles.

The new family of launch vehicles was to have two key characteristics. First, in order to cut costs to the maximum extent possible, it would use unified rocket stages and engines. Second, it would rely on non-toxic, ecologically clean propellants, with preference being given to liquid oxygen and kerosene. The reasoning behind this reportedly was that “the number of launches of [space rockets] would be much higher than the number of test flights of nuclear missiles with [storable] propellants.” What also may have played a role were a series of low-altitude Proton failures that had contaminated wide stretches of land at or near the Baykonur cosmodrome. The basic conclusions of the study were approved on 3 November 1973 at a meeting of GUKOS [45]. Although not stated specifically, the long-range goal of this effort seems to have been to phase out all or most of the existing missile-derived launch vehicles.

Initially, the primary focus apparently was on unifying the light to heavy class of rockets, because at the time these decisions were made super-heavy rockets and reusable shuttles were still a distant and vague goal. It would seem that three design bureaus were ordered to come up with proposals for such a family of launch vehicles under a competition called Podyom (“Lift”). Both Branch nr. 3 of TsKBEM in Kuybyshev (which became the independent TsSKB in July 1974) and Chelomey’s TsKBM put forward plans to refit their respective Soyuz and Proton launch vehicles with the Kuznetsov bureau’s LOX/kerosene NK engines originally built for the N-1 rocket. The former Yangel bureau in Dnepropetrovsk (now called KB Yuzhnoye and headed by Vladimir Utkin) also weighed the idea of using NK engines (which after all were around and had been tested), but in the end favored the new generation of LOX/ hydrocarbon engines being designed by Energomash [46].

Actually, by this time Yuzhnoye had been working for several years on a new medium-lift launch vehicle (11K77) burning storable propellants. In December 1969 it had been ordered by GUKOS to develop a new rocket capable of placing 8 tons into low polar orbits and 2 tons into highly elliptical Molniya-type orbits. The initial idea in 1970 was to build a three-stage rocket with 3.6 m diameter modules. The following year attention turned to a rocket derived from the bureau’s R-36M, a new ICBM that had been approved by a government decree in September 1969. By retaining the 3.0 m diameter of the R-36M’s rocket stages, no fundamentally new manufacturing techniques would be required. The 11K77 would now consist of a pair of R-36M first and second stages stacked on top of one another plus a newly developed third stage. In 1972 Yuzhnoye also designed a slightly less powerful rocket designated 11K66, essentially a two-stage R-36M with increased propellant load capable of orbiting 5.9 tons.

When Yuzhnoye made the switch to LOX/kerosene under the Podyom program in 1974, it opted for a vehicle maintaining the 3.0 m diameter of the rocket stages, but employing parallel staging. This version of the 11K77 would fly the single-chamber LOX/kerosene engines then being designed at Energomash. The second stage, acting as the core, would have a 130-ton thrust RD-125 engine, and the two first-stage modules flanking the core would each have three 113-ton thrust RD-124 engines. These engines had combustion chambers of roughly the same size and pressure as those of the R-36M first-stage engine. Payload capacity to low orbit was now 12 tons.

By early 1975 Energomash’s Department 728 had made enough progress on the powerful 600-ton thrust RD-123 for Yuzhnoye to incorporate it into the 11K77 design. This made it possible to replace the two modules of the 11K77’s first stage by a single module, although its diameter would have to be increased to 3.9 m, which was the maximum that could be transported by rail. The second stage would now be placed on top the first stage, turning the 11K77 into what the Russians call a “mono­block’’ booster. After a convoluted development path, the rocket had now acquired the configuration in which it later became known to the world as Zenit. It could also serve as the basis for a lighter rocket (11K55) and a heavier version (11K37), with the three covering the whole payload range from “light” to “heavy” (see Chapter 8) [47].

Being in the heavy to super-heavy class, Glushko’s RLA family was not part of the Podyom competition, but as plans for a large Soviet shuttle gained more support in 1975, so did the idea of unifying the first stage of the RLA rockets with that of the future medium-lift rocket. It is unclear if this consideration played a significant role early on in the Podyom competition. If it did, TsSKB and TsKBM had betted on the wrong horse by anticipating that whatever followed the N-1 would also carry NK engines, while Yuzhnoye had made the right choice by picking the new Energomash engines. However, the history of the 11K77/RLA unification is a complicated chicken-and-egg story, with sources differing on whether the initiative to unify the first stages came from Glushko or Utkin. At any rate, Yuzhnoye emerged as the winner of the Podyom competition in 1975, no doubt because its medium-lift rocket could now act as a test bed for the first stage of the rocket that would power the Soviet space shuttle to orbit.

The 11K77 is the only thing that ever came out of Podyom. Yuzhnoye’s proposed light-class and heavy-class rockets never flew and the whole idea of a standardized fleet of dedicated, environmentally clean space launch vehicles in the light to heavy class remained a distant dream, probably because it infringed too much on design bureau interests. In fact, most of the IRBM and ICBM-derived launch vehicles conceived in the 1960s continue to fly today, although another attempt is being made to develop a standardized rocket fleet under the Angara program (see Chapter 8).