In 1963, OKB-1's Branch No. 3 at Kuibyshev headed by D.I. Kozlov was charged with the responsibility for all work on improvements, the development of new versions, flight tests and the operation of R-7 launchers [1]. A unified launcher designated 11A57 became the first R-7A-based space carrier vehicle to be developed by Branch No. 3 which is now the well-known State Scientific Production Rocket Space Center TsSKB-PROGRESS (Samara).

BY TIMOTHY VARFOLOMEYEV St Petersburg, Russia

The Right Decision

During 1962-1963 the Kuibyshev Branch No. 3 received from Korolyov's OKB-1 all the technical documentation, including blueprints, on the operational launchers 8K72K, 8A92 and 8K78, also on launchers of the Soyuz complex which were only under development at that time.
Rather than develop two versions of a three-stage R-7A-based launcher -for manned and for unmanned missions - the Branch's leaders proposed designing one unified version. This launch vehicle, which received the next consecutive designator number, 11A57, was intended initially to carry a variety of payioad types, including both manned and unmanned spacecraft for an orbital assembly complex and reconnaissance satellites of the Zenit Class.
As became clear shortly afterwards, it was the right decision. In early 1964 OKB-1 started construction of a three-man version of the Vostok spacecraft called Voskhod, and then, in mid-1964 the circumlunar programme Soyuz was radically revised. One of the scenarios envisaged the use of the 11A57 launcher for putting the circumlunar spacecraft 7K-L1 in parking orbit, but this variant was rejected; so, the 11A57 had only spacecraft of the same Vostok-based type left to launch. The first of them would become the photo-reconnaissance satellite Zenit-4.

An Early Version of the Unified Launcher

The unified 11A57 launcher would of course be powered by unified engine units. In 1962 Glushko's OKB-456 was asked to develop one unified uprated version of the RD-108 engine for 11A57's central sustainer Block A, instead of the earlier specialised versions 8D727K and 8D727P. This unified motor designated 8D727 was built and tested during 1962-early 1963. As it did not have a final stage of thrust, the system of automatics of the vernier chambers could be simplified and reliability increased. The motor met the requirements of the SKA Regulations which set out the requirements on design, production and testing of space hardware intended for manned missions.
In mid-1963, assembly of the first batch of unified launchers began at the Progress Machine Building Plant. Although the central sustainer Block A of the 11A57 would be powered by the 8D727 engine, the first batch of unified launchers would be powered by 8D727P and 8D727K motors as a few dozen of them had been produced during 1962 and 1963.
The strap-on booster Blocks B, V, G and D were powered by an improved version of the RD-107 motor designated 8D728.
The third stage Block I was basically the same unit that was being developed for the 11A55 project but somewhat modified and designated 11A57I. It was powered by Kosberg's engine 8D715P (whose modern designation is RD-0108) and was equipped with an improved control system. A cylindrical 2.3 m long adapter was attached to the forward end of Stage 3 to place the Zenit-4 satellite on it Originally, in 1961, such an adapter was designed to attach Vostok-7 to an early version of the Block I of the 8K711 launcher, but it was never flown. In August-November 1962 this adapter was first used on Stage 3 of the 8K78 launch vehicles which injected the Venera and Mars probes into interplanetary trajectories. A nose fairing for the 11A57 was also adapted from the 8K78 launcher. The first launch of the 11A57 vehicle occurred on 16 November 1963. A prototype of a new photo-reconnaissance satellite Zenit-4 (Product 11F69) was successfully put into Earth orbit The spacecraft was officially called Kosmos-22 and carried high resolution photo-equipment The early version of the 11A57 launched only unmanned Zenit-4 satellites during flight tests in 1964 and 1965. All fourteen launches were successful.

Voskhod Programme

By a joint decree of the Central Committee of the Communist Party and the Council of Ministers dated 3 December 1963 the OKB-1 was charged with building three circumlunar spacecraft 7K in August-September 1964 [2], but it was obvious at that time that this spacecraft would not fly in 1964. In order to leave the Gemini programme behind the Soviet leadership authorised OKB-1 to hurriedly build a three-man spacecraft. As early as November 1963 Korolyov's design bureau had started work on such a spacecraft. In late December 1963, after one month of intensive study, Korolyov put two proposals forward. The first was to remake the one-man spacecraft SKA Vostok into a three-man version, which was designated 3KV. The second was to redesign the two-man circumlunar spacecraft 7K into a three-man orbital one designated 7K-OK* [3].
On 4 February 1964, Korolyov received an official order to convert four SKA Vostok spacecraft, which were under construction, into the three-man 3KV version [4]. In mid-February 1964, the three-man spacecraft based on the Vostok design was officially called Voskhod [5].

11A57 - The Unified Launcher for Heavy Satellites

On 13 March 1964, the Military Industrial Commission of the Council of Ministers by its Resolution No. 59 authorised OKB-1 to build four flight-ready Voskhod spacecraft and the launch vehicles for orbiting them [6]. During summer of 1964, the early version of the 11A57 was modified for the forthcoming manned missions of the Voskhod programme. Engine 8D727P of the central sus-tainer Block A (Stage 2) was replaced by its unified version 8D727.
Block I (Stage 3) was somewhat modified. It was powered by an improved version of the 8D715P engine which was designated 11D55 (whose modern conventional designation is RD-0110). The point is that static firing and flight tests of the 8D715K and 8D715P motors conducted during 1962-1964, had revealed that it was necessary to increase the strength of crucial portions of the motor and to replace some of the materials used. Moreover, during some ground bench tests, high frequency chamber-pressure oscillations took place [7]. A stricter range of demands was set out for production, check-out and tests. (The 11D55 showed itself to be a reliable motor - indeed, it continues to be in operational service up to the present as the engine unit of Block I of the 8K78M and 11A511U launch vehicles.)
The nose fairing of the 11A57 vehicle for manned missions was essentially modified. The crew of a Voskhod spacecraft did not have ejection seats, so they could not be catapulted out in an emergency. In order to ensure reliable separation of the shroud with itstwo halves falling away, additional spring ejectors were mounted. In addition, the fairing was powered by two pairs of small solid motors positioned atop of the two halves in order to part and rotate them off if the spring ejectors failed.
The first improved 11A57 vehicle was launched on 6 October 1964 carrying an unmanned test version of the 3KV Voskhod spacecraft officially called Kosmos-47.
Much later on, launch vehicle 11A57 was called Voskhod because it was launching manned spacecraft of the same name, although there were only two manned missions. On 12 October 1964 the first three-man Voskhod (Object 3KV) was orbited and on 18 March 1965 the 11A57 vehicle put into orbit the two-man Voskhod-2 (Object 3KD) on board of which the first EVA was performed. After that the 11A57 launched only unmanned spacecraft, although four more manned Voskhod missions were to have been undertaken during 1965-1966 according to Korolyov's plan [8].
Towards the end of 1965 the engine 8D727P - a power-plant of the Block A (Stage 2) of the 11A57 - was replaced by the unified version 8D727, and the engine 8D715P (only twenty flyable models of which had been produced) was replaced by the 11D55.
Flight tests of the photo-reconnaissance Zenit-4 spacecraft finished with a launch on 28 October 1965, and in December 1965 the second Soviet reconnaissance system based on satellite 11F69 Zenit-4 and launch vehicle 11A57 was put into operational service with the Soviet Military Forces. Since 1966 the 11A57 launch vehicle has been the backbone of Soviet launch capability for orbiting photo-reconsats of first, second and third Zenit-class generations. On 6 April 1966 the 11A57 was first launched from the Plesetsk launch site. During 1966-1967 and thereafter the 11A57 took the place of the 8A92 vehicle in launching operational Zenit-2 satellites because the 8A92 was removed from production.
In 1967-1968 the launch vehicle was modified for forthcoming missions with improved satellites of the Zenit class. The basic packet 8K74/III of the combined Stages 1/2 was replaced by the unified packet 11S59 (which will be described in the forthcoming Part 14), enabling the payload capability to be increased from 5.8 to 6.1 L The nose shroud was lengthened by 0.4 m and received its own designation 11S512.
On 21 March 1968 the 11A57 launcher orbited the improved photo-reconsat Zenit-2M (Product 11F690) officially called Kosmos 208. In 1970, after two years of flight tests, satellite Zenit-2M was put into operational service and received the operational code name Hektor [9].
On 31 October 1968 the next improved satellite, Zenit-4M (Product 11F691) was launched for the first time by the 11A57. A photo-reconsat of this version was put into service in 1971 under the operational name Rotor [9]. The modified nose fairing for this spacecraft was designated 11S513.
During 1970-1976 the 11A57 was launching yet another photo-reconsat, Zenit-4MK (Product 11F692). Again some changes were made in design of the noise fairing - a T-formed projection appeared on a side of the cover. This fairing received the designation 11S514. It is now well-known as the nose shroud of the 11A511U launcher carrying satellite Resurs-F1 and F2. The Zenit-4MK was put into service in 1972 [10] under code name Hermes.
On 7 April 1972 launch vehicle 11A57 put into orbit the international scientific satellite Energia (Object 13KS) officially called lnterkosmos-6. Its development was based on the Zenit-2M satellite.
Launch vehicle 11A57 showed a high level of reliability. The document '3KA Regulations' played an important part in increasing the reliability of Soviet space hardware. The 11A57 launcher was used on more space missions that any other at that time. During 1963-1976 a total of 298 launches took place, only 14 of them ended in failure.
The last launch of the 11A57 came on 16 June 1976 from the Plesetsk launch site. After that it was removed from operational service and its place was taken by the new R-7A-derived launcher 11A511U which will be described in a forthcoming Part 15.