On designing of technical and launch complexes of R-7 rocket

Some scientific-technical and practical issues are considered that were solved during the design of technical and launch complexes of R-7 rocket which provided the launch of the first artificial Earth satellite.

During the first ten years of rocket engineering development State Special Design Bureau (SSDB) "Spetsmash" later known as "V.P.Barmin Design Bureau of General Mechanical Engineering", remained the only main enterprise in our country dealing with development of complexes of ground launch equipment and fuel loading equipment, load handling facilities and supporting facilities for launch preparation and ballistic rockets launch.

Taking into consideration the experience gained by SSDB "Spetsmash" during the first years of rocket engineering development in the country, the Design Bureau was entrustedљ to develop the specified Technical and Launch Complexes for the test range complex of unique intercontinental ballistic rocket R-7 by Government Regulation issued on March 20, 1954. The head of SSDB "Spetsmash" Vladimir Barmin was appointed the Chief Designer.

Design of such a complex, unique both in our country and abroad, offered a large-scale multi-aspect scientific and technical problem.

One should take into account that at that time there was only the experience of designing mobile ground complexes for medium-range ballistic rockets - R-1 and R-2 - differing in essence from R-7 rocket complex being developed. For example, R-1 and R-2 rockets launching was accomplished from mobile launch pad which was equipped with gas deflector and moved by a truck.

Elaboration of new engineering solutions accounting for optimal system linkage of equipment and launch facilities with the rocket in a single rocket complex was required to solve the problems of R-7 launch preparation and launch itself.

Council of Chief Designers headed by S.P.Korolev significantly influenced the elaboration of optimal solutions. Vladimir Barmin was also a member of the Council.

The following scientific and technical problems were solved during the development of launch complex (LC):

-         mutual linkage of force construction arrangement of the launch system (LS) with the rocket;

-         launch dynamics and non-impact rocket boost;

-         large-size rocket mounting on the launch system under heavy wind loads;

-         transportation of fully assembled large-size rocket by the transporter-mounter (TM) via railway;

-         launch gas dynamics and rocket thermal protection;

-         high-speed fueling with propellant components and gases at remote control of this process, etc.

Linkage of force construction arrangement of the launch system with multiple-unit rocket of batch scheme configuration in case of wind speed up to 20 m/s was a problem of holding a rocket on a launch system. Strength characteristics of rocket tail section deeply influenced the choice of launch system. Typical for rocket engineering versions of the rocket resting with its tail section upon several (five) launch pads clustered into a single launch system were studied at the first stage. However, to resist wind loads all of them required considerable reinforcement of the rocket end section as compared with its free-flying conditions. S.P.Korolyov even offered to study a version of creating a high wall around the launch site for wind protection, but the launch would be considerably complicated in this case. Therefore for the first time in rocket engineering the rocket suspension layout by its supporting portions was applied. The supporting portions were located in the upper force bearing ring area where all the units joined into an assembly, so there was no need for reinforcement of rocket tail section as compared with its free-flying conditions.

Such a decision required development of unique launch system in which the rocket before launch was held by two force rings - the upper and the lower ones. The necessity of azimuthal aiming of rocket demanded locating of the elements of mentioned force rings on a special turning platform. Special hydraulic suspension system was applied to hold the rocket vertically in the launch system before the launch.

The launch system constitutes a single dynamic system with a rocket at launch. The construction of launch system provides the vertical rocket movement at initial stage. Then the upper and lower force rings of the launch system get broken and the following launch system elements are disengaged from the rocket: bearing arms, supporting trusses, guide rods. To provide high reliability of rocket complex the experimental testing of full-scale launch system was carried out with the rocket prototype under plant conditions. The prototype was filled up with bichromate aqueous solution and imitation of rocket lifting was accomplished with the factory crane. The problems to be solved during the testing included:

-         synchronous withdrawal of bearing arms, supporting trusses, guide rods of the launch system;

-         preventing the launch system elements from collision with rocket;

-         determination of bearing arms' caps shape which ensure the jam-free launch under the imitation of the heaviest wind loads.

Absolutely new launch system layout required the development of original mounter. Wind load was one of the main external factors needed to be taken into account while considering the mounting. Wind load has dynamic component provided by dynamic pressure fluctuations causing rocket vibrations under wind impact. The accepted assembly procedure is a specific operation sequence during which the rocket is transmitted from the transporter-mounter to the launch system. During the whole process the control is provided for the forces imposed on rocket during the assembly. The control is carried out by force measure devices installed at the bottom of bearing arms.

The transporter-mounter technology was also absolutely new as it provided the transportation of fully assembled large-size rocket via railway from the technical complex to the launch site accomplishing all the requirements.

Choice and substantiation of gas dynamic launch layout were complicated scientific and technical problems. Deepened launcher with ejection type gas dynamic layout was applied in this complex for the first time. The ejector was organized by special mutual layout of the launch system, facilities and rocket via deepening the rocket by 6.3 m from ground level into the launch pad aperture. This resulted in annular gap between the rocket and launch system where effective cold air flow washing the rocket tail section was generated by rocket engines gas jets ejection. While the rocket engines were functioning at the main stage mode, complete withdrawal of hot gases from the rocket was provided, and so thermal loads affecting the rocket were decreased to the allowable values. Layout parameters were substantiated and tested on basis of calculations, experimental refinement on models, and full-scale rocket launches. During the first launches it was revealed that ejection efficiency was insufficient at the initial stage of engines operation at a pre-stage as the products of incomplete combustion possessed low ejection velocity. Gases on their way from rocket to deflector burnt down and went up embracing the rocket. To eliminate this effect special gas protection system was developed (two-tier ejection system) which allowed removing 500 kg of the heat-resistant coating from rocket tail section.

Engineering solutions concerning the process of fuelling at this launch complex were also new. They provided fast filling of the rocket with fuel components and compressed gases via remote control of the processes.

Besides LC equipment, the process equipment of technical complex was also developed to service the rocket, its head parts, and space objects. This equipment provided transport, assembly, testing operations, etc.

SSDB "Spetsmash" worked in cooperation with грй-31, глвфн, National Research Institute (NRI) "Stroydormash", SSDB "Dormash", Design Bureau (DB) of Ural Railcar Plant, NRI "Gidromash", DB of Kalinin Railcar Plant, рлв-12, RI-88 and other enterprises while designing the Launch and Technical Complexes. Specified Launch and Technical Complexes provided the launch of the first artificial Earth satellite and subsequent spacecraft launches including Gagarin launch in 1961.

Such Launch Complexes were repeatedly upgraded during their operation. The last modernization was carried out for "Soyuz-2" rocket in 2002-2006. The specific feature of modernized launch at Baikonur launch site is its versatility which allows launching both "Soyuz-2" and "Soyuz" rockets.

Launch Complex for "Soyuz-ST" rocket is developed on basis of this Launch Complex at Guiana Space Centre (GSC). This LC has a number of essential differences from other Russian LCs. They are:

-         transportation of rocket from technical complex to launch complex without the orbit stage but with its further installation on the rocket at launch complex;

-         mobile service tower for arrangement of orbit stage on the rocket and its service;

-         designing a new launch system without units and mechanisms of turning platform;

-         creation of new automated control system for process equipment of the launch complex using the modern elemental base, etc.

In conclusion we should note that:

1. Accuracy of accepted engineering solutions concerning LC and Tу of R-7 rocket was confirmed by a great number of rocket launches and the first Earth artificial satellite launch.

2. Creation of LC and TC for R-7 rocket was a large step in development of rocket engineering and durable scientific and technical basis for designing new complexes for other rockets ("Soyuz", "Proton", N-1, "Energia-Buran ", "Soyuz-2", "Soyuz-ST" at GSC, etc.).

3. Accepted engineering solutions ensured long life cycle of complexes. The overall number of launches from R-7 rockets LC exceeds 1700 launches of rockets with spacecrafts of different purposes, and further active exploitation of the LC is planned.