Soviet Solid Rockets - 1940s

Toward the end of the 19th century, solid propellant rockets were eclipsed by rifled artillery in military applications, lost their former significance, and became used only for secondary purposes such as illuminatian, signalling, and fireworks, etc. This occurred in part because of the lack of a scientific theory explaining rocket propulsion, the low effectiveness of the only propellant then used in rockets - gunpowder - and the lack of advance inn the design of existhg rockts that hardly chnged in the course of centuries.

But the pincipal advantages inherent in the rocket remained: simplicity of design and especially the simplicity and ease of mounting for launching. These considerations constantly attracted the attention of inventors throughout the world. In Russia, work directed toward improving powder rockets never ceased for even a year. Engineers developed three basic sizes of scaled-up rockets of 68, 82, and 132 mn calibers. The latter two subsequently became the basic calibers of Soviet rocket missiles for decades: the RS-82 and the RS-132, later named Katyusha.

In the interest of developing, strengthening, and broadening the work in rocket technology in the future, a mave from a small organization to a large scientific research institute with a well-equlpped laboratory and experimental base appeared urgent. Utilizing the two most productive functioning orgization - Leningrd's GDL and Moscow's GIRd - in October 1933 a single Jet Propulsion Research Institute (RNII) was created, and GDL'S work in powder rockets amd on a series of other problens were transfemed to RNII. At this time a final design of the 82mn and 132mn rockets was almost cmpleted and brought to the stage of being put into production.

The Soviets were rightfully proud of Katyushas. Soviet military historians asserted that neither the Germans nor the Allies had managed during, and immediately after, the war to produce such effective reactive solid-propellant projectiles using special nitroglycerin powder propellant. These projectiles had solid-propellant rocket engines that were a great deal simpler, more reliable, and less expensive than any liquid-propellant engines.

NII-4 in Bolshevo had been created as a result of the historic USSR Council of Ministers decree dated 13 May 1946, and the order of the minister of the USSR Armed Forces dated 24 May 1946. The first postwar directors of not only NII-4, but also the State Central Firing Range in Kapustin Yar and the new departments of the Main Artillery Directorate had come to large missile technology from the simple and small solid-propellant projectiles of the Katyusha. NII-125 was the main institute specialized in research on solid propellants for rockets.

In solid-propellant missiles, the charge and the engine are all one piece and cannot cool the nozzle the way the fuel in a liquid-propellant rocket engine does during the combustion process. The intensity of the combustion product’s thermal effect on the shell of the rocket engine casing becomes intolerably high when the engine operates for a prolonged period of time. Moreover, during prolonged storage or exposure to operating pressure, the propellant charge developed cracks, the lateral surfaces of the charge ignited, and the temperature became so high that the body burned through.

Charges made of stable, smokeless, granular powder containing special solvents proved to be good for missile projectiles, but quite unsuitable for large rockets. Conventional solid-propellant rocket engines also had a low thrust performance index compared with liquid-propellant rocket engines.