Unique control system for unique rocket

E.L.Mezhiritskiy, G.M.Priss, Yu.V.Trounov

S.P.Korolev in his memorandum (May 1954) on development of artificial Earth satellite mentioned that creation of R-7 rocket as satellite launcher had been prepared by all previous work of all development organizations (liquid-propellant jet engines, control system, gyroscopes, launch center and so on).

In fact, by the beginning of R-7 development (May 1954) N.A.Pilyugin's team and other organizations headed by Chief Designers who were the members of Council of Chief Designers, had 8 years of experience in 1200 km range ballistic rocket development. The first R-1 rocket was the analogue of German V-2 rocket transferred to the Soviet element and material base. But further developments (R-5 and R-11) were completely original. Experience accumulated during components design and flight tests of five rocket types created a reliable base for absolutely new type of carrier rocket.

R-7 ("Semyorka") was a unique rocket developed in S.P.Korolev's Design Bureau (DB) at his direct participation owing to his strength, persistence and will.

It was the first-ever intercontinental rocket with unusual structure and unique components: engines, ground launch and fuel-filling equipment, and control system developed under N.A.Pilyugin's direction participation.

Control system (CS) structure analysis showed the necessity of implementing new concepts in autonomous CS supplemented with radio system for motion control corrections (need in complex CS creation). In two years flight control tests of R-7A with autonomous control system began.

The necessity of using new control concepts was caused by extremely complicated "package" dynamic scheme of rocket as an object of stabilization system with characteristic harmonics of bend oscillations, some of which approached operating frequency of stabilization automatic machine. This should be supplemented with the necessity of registration of liquid components oscillation in ten tanks of flying a rocket, synchronism of these components' rate and minimization of fuel components remains at the moment of engines' shutdown. This should essentially improve power performance of a rocket. The demanded accuracy of rocket position and velocity at the moment of engine shutdown led to necessity of engine functioning control. All of this defined unprecedented demands in respect of control system and its devices.

S.P.Korolev's and N.A.Pilyugin's organizations together with Institute of automatics and telemechanics of Academy of Sciences (IAT AS) and B.N.Petrov's team conducted analysis and suggested development of new circuits in control system structure previously unknown both in V-2 and in R-1, R-2, R-3 rockets. These circuits were aimed at: control of normal and side deviations of rocket center of mass (so-called NS and SS systems); control of apparent velocity at active part of rocket flight (RAV system); fuel rate control and synchronization of its rate from side block's tanks (SETS system);

One should note that functioning of RAV and SETS systems should be interconnected because both systems influence the same regulated object, i.e. liquid-propellant rocket engine (LPRE).

The Concept of LPRE control was declared by V.P.Mishin at the beginning of the 1950^th, and the first works on generating the equations of LRE were carried on in V.P.Glushko UDB. First works on LPRE dynamics and controllability were carried out in IAT and resulted in mathematical description of LPRE. However, practical definition of LPRE control possibilities and its dynamic characteristics was required.

Control system of new R-7 rocket required theoretical researches in the area of algorithms of rocket motion control, development of new control circuits' parameters, schemes and structures of new devices and their simulation and testing. This was an enormous amount of work.

All was unprecedented in this work including its difficulties and problems.

One of the problems was the necessity of theoretical researches in searching of optimal algorithms of rocket motion control considering the vibration of its airframe and liquids and new circuits operation. These researches were accompanied with huge amounts of calculations and works at simulating plants.

At the beginning of the 1950^th the first simulating analog plants were used which were rather imperfect, bulky, required numerous staff, being at the same time rather unreliable. All calculations were carried out manually on calculating machines "Rhinemetall".

Being a single-minded person of principle, Nicolay Alexeyevich Pilyugin headed these works using the existing cooperation of organizations. According to the tasks set by him V.I.Kuznetsov began development of gyroscopic sensor, S.P.Korolev's DB started designing driving gear for RAV system under supervision of B.E.Chertock, A.S.Abramov's organization began development of SETS devices. The whole NS and SS systems from sensing elements to signal converters and other equipment were created at N.A.Pilyugin's organization. In collaboration with V.I.Kuznetsov's organization sensing elements were mounted in gyroscopic device.

N.A.Pilyugin's organization conducted development of generalized laws of R-7 rocket motion control, considering the information from new systems as well as their complex maintenance and coordination with other systems, LPRE and ground test-launch equipment, i.e. CS complex was designed.

N.A.Pilyugin himself actively supervised the development R-7 CS, but his ideas, proposals and concepts were mainly implemented in RAV system and sensing elements of NS-SS.

The amount of experimental work and tests performed during creation of R-7 control system should be particularly emphasized. The following tests were conducted: obligatory independent tests of single devices, tests of chosen parameters and adjusting coefficients on modeling plants, complex tests at test beds, and some other experiments. For the sake of RAV and SETS systems numerous special fire tests of LPRE were carried out at test beds at V.P.Glushko's organization together with tests at electronic modeling plant created in IAT.

According to S.P.Korolev's proposal approved by Council of Chief Designers, the experimental rocket M5-RD was developed on basis of R-5. Series of ten rockets equipped with all new systems (NS, SS, RAV and STE) was subject to flight tests. Two of these tests took place in the period of February, 16 - August, 18, 1956. Together with control systems new "Tral" and "Fakel" systems were tested. Radio systems were tested at three launches of R-5R experimental rocket.

Perhaps, the experience of special experimental rockets creation in order to test new control systems was unique for domestic rocket engineering.

M5-RD rocket launches were preceded by the fire test at RI-88 Branch #2. Favorable results of flight-control tests (FCT) of M5-RD rockets confirmed correctness of new systems design. Then five fire tests of side blocks, three tests of central block and two tests of R-7 rocket itself were carried out.

Positive results of fire tests which ended in March 1957 cleared the way for FCT. They started in spring, 1957 at new range where the first rocket was delivered in March, 1957.

As is well known, the first three launches of R-7 were unsuccessful. The forth launch was successful and S.P.Korolev delivered to State Committee his proposal to begin preparing for launch of a simple satellite. The proposal was accepted after heated discussion. The fifth successful R-7 launch took place on 07.09.1957. Less than a month remained before the launch of the first artificial satellite (AS).

N.A.Pilyugin was present at the launch on October 4, as well as at all the previous launches. In launch bunker he was accompanied by our test researchers V.K.Krotov, N.M.Lakuso and A.D.Pankov, and a group of our developers.

Results of launch were announced to the whole delighted world. Specialists at the range and in developing organizations were the first who exulted at their success even not realizing the scale of their achievement.

AS launch demanded insignificant improvements which provided the required launch trajectory and connection between satellite electrical circuit and rocket circuit. However, the third successful launch was itself an important fact on the way of R-7 rocket development.

The designed rocket complex turned out to possess unique (for those times) characteristics and to demonstrate incredible liveness and ability to be improved. For example, initial version of control system endured 25 modernizations for various tasks in seven rocket modifications. Only several years ago introduction of essentially new control system has started. R-7 rocket still operates, the number of its launches is close to 2000. There is no similar rocket in the world. All first steps in the nearest space, in development of Solar system, all manned launches from the territory of our country were carried out using R-7 rocket. And it flies being controlled by the system created by the team supervised by twice a Hero of Socialist Labour, Academician Nikolay Alexeyevich Pilyugin.