French solid motors for missiles and rockets from WWII to the Sixties

摘要

At the beginning of research on solid propulsion, France had a peculiar organization because of the state monopoly on the production of gun powders existing at that time: Direction des Poudres was responsible for the energetic part of the solid motor and supplied private companies or government agencies with grains. Before World War II, some industrial capacity in the field of extruded double base (EDB) propellant for guns did exist at Direction des Poudres. After the war, EDB propellants (SD grains) were soon developed and used on small diameter missiles. Cast double base propellant (CDB) development started in 1950. This family (Epictete grains) allowed higher sizes, compatible with all types of tactical missiles. Shortly afterwards the first French composite propellant (Plastorgol grains) appeared, using PVC binder. During the 1950's, several rocket vehicle programs using these propellants were developed, particularly a series of long range anti-aircraft missiles. The motors developed for these missiles gave birth to several families of test rockets and sounding rockets (ONERA, SEREB, Sud Aviation,...).rnIn 1959, the decision to develop a deterrent force mainly based on the use of ballistic missiles deeply reoriented the French rocket industry. Created in order to manage the development of the ballistic missiles, SEREB initiated a program of basic ballistic studies. This program began with vehicles using available 55 cm and 80 cm Plastorgol solid motors. It continued with liquid rockets and also solids using a new propellant (Isorgol grains) based on polyurethane binder. The most powerful of these vehicles (the Precious Stones series) was Saphir, constituted by an Emeraude liquid stage topped by a solid Topaze. In December 1961, three months before the official creation of CNES, it was decided to develop a space launcher, named Diamant by replacing the Saphir payload by a third stage. This new upper stage was tested atop a reliable Plastorgol-based rocket, forming the Rubis 2-stage vehicle, before the maiden - and successful -launch of Diamant in November 1965.rnThis paper presents the evolution of the French solid propulsion during this period (up to 80 cm in diameter) by describing the main applications in the field of missiles and their adaptation to the domain of the sounding rockets and space launchers.