Ballistics rockets

The astronomical investigations of space are not restricted solely to optical radiations. Space technology, starting with ballistic rockets and, in particular, satellite technology, have enabled astronomers to study X-ray sources which are the result of interstellar catastrophical events such as the collapse of a solar system. These observations are only possible outside the atmosphere of the Earth (see Sect. 4.3.3). 

Polymer-based rocket propellants are generally referred to as composite propellants, and often identified by the elastomer used, eg, urethane propellants or carboxy- (CTPB) or hydroxy- (HTPB) terrninated polybutadiene propellants. The cross-linked polymers act as a viscoelastic matrix to provide mechanical strength, and as a fuel to react with the oxidizers present. Ammonium perchlorate and ammonium nitrate are the most common oxidizers used nitramines such as HMX or RDX may be added to react with the fuels and increase the impulse produced. Many other substances may be added including metallic fuels, plasticizers, stabilizers, catalysts, ballistic modifiers, and bonding agents. Typical components are Hsted in Table 1. 

Without the influence of burning rate catalysts most of these hydrocarbon prop bits have similar burning rates and ballistic behavior. They may differ significantly in mechanical properties, particularly as a function of temp. Most hydrocarbon-based composites are used in larger rockets because of their ease of fabrication and high specific impulse. Polaris first and second stages, the Titan 3C booster rocket and Mlnuteman are all powered with composite proplnts... 

Klunsch (Ref 72) has incorporated hydra-zinium nitroformate and aluminum hydride in plastisol NC formulations which cure at room temp without undesirable gas formation. A number of such formulations and calculated ballistic results are given in Table 21. Although these are attractive propint s from the standpoint of potential energy, their impact sensitivity was not described. Similar plastisol binder propellants in Table 18 were sensitive enough to impact to warrant extreme caution in processing into rockets. 

Corner, J., Theory of the Interior Ballistics of Guns. Chapman Hall, London, 1950. Daboo, J. E., Solid-fuel Rocket Propulsion. Temple Press, London, 1962. 

Similar to nitramine composite propellants and TAGN composite propellants, AN composite propellants produce halogen-free combustion products and thus represent smokeless propellants. However, their ballistic properties are inferior to those of other composite propellants the burning rate is too low and the pressure exponent is too high to permit fabrication of rocket propellant grains. In addition, the mechanical properties of AN composite propellants vary with temperature due to the phase transitions of AN particles. 

When HNF or ADN particles are mixed with a GAP copolymer containing aluminum particles, HNF-GAP and ADN-GAP composite propellants are formed, respectively. A higher theoretical specific impulse is obtained as compared to those of aluminized AP-HTPB composite propellants.However, the ballistic properties of ADN, HNIW, and HNF composite propellants, such as pressure exponent, temperature sensitivity, combustion instability, and mechanical properties, still need to be improved if they are to be used as rocket propellants. 

Amorphous carbon comprises various combinations of carbon atoms. Charcoalis a typical amorphous form of carbon and is used as a major component of black powder and ballistic modifiers of rocket propellants. Charcoal contains a large number of tiny pores and the total surface area within the structure is approximately 1-3 m mg This surface area plays a significant role as a catalytic surface in various chemical reactions. It is well known that the burning rate of black powder is very fast because of the large surface area of the carbon structure. 

In sending a rocket into the sky we are calling into action several laws of physics and chemistry, and the same laws apply whether the application is a small firework rocket weighing a few ounces or a solid propellant booster for the space shuttle containing around 300 tons of propellant. These fundamental processes may be conveniently divided into internal ballistics and external ballistics. 

The position of an object in flight, such as a rocket, as a function of time is routinely determined using ballistics equations and tables which are commonplace but rather complex. 

BALLISTICS (INTERNAL) The science of internal ballistics is concerned with the propulsion of a projectile such as a shell along the tube of a mortar by gas pressure acting on the base of the shell, or, in the case of rockets, by the backward exhaust of the gas jet. 

BALLISTICS (EXTERNAL) Extemal ballistics deals with the science of the motion of bodies such as shells and rockets in the earth s atmosphere and under the effect of the earth s gravitational field. 

Hercopel a unique all-epoxide cure composite solid propellant with excellent mechanical and ballistic properties. Its outstanding performance in extended environments makes it well suited for tactical missiles Double-Base Solid Propellants a wide variety of physical and ballistic properties which can be tailored to meet specific performance requirements. Their high specific impulse and excellent reproducibility are two of the many reasons Hercules double-base propellants are found in many of our rocket motors and gas generators used for both military and space applications... 

Internal Ballistics of Barrel Weapons and of Solid Propellant Rockets (Vnutrenniya Ballistika Stvol nykh Sistem i Porokhovykh Raket). Title of the book by M. E. Serebriakov, GosNauch —TekhlzdatOboronghiz, Moskva (1962), 3rd edition, 703 pp... 

Post-WWII. After WWII most LP R D shifted from Germany to the USA and the USSR. Technical progress since 1945 in LP for rockets can be characterized by a host of minor improvements rather than major advances, and some spectacular applications of LP in rockets for military use and for space exploration, eg, in ICBM s (Intercontinental Ballistic Missiles) and in USA USSR Moon, Mars Venus shots . Thus the major developments since WWII have been primarily in the application of existing, though improved, propulsion systems to such highly publicized rockets as Sputnik, Vanguard, Soyuz, Saturn, Vostok, Apollo, Explorer, etc... 

Ballistika Stvol nykh System i Porokhovykh Raket (Interior Ballistics of Gun Barrel Systems and of Solid Propellant Rockets), Oboronghiz, Moskva (1962). Abbreviated translation by Dr V. Nekrassoff for the US Navy, p 22 (under Bernoulli)... 

Gadolin, A.W. (1828-1892). A Russian bal-listician who, in collaboration with N.V. Mayevskii, proposed using propellant in hexagonal form with one or 7 perforations Refs 1) M.E. Serebryakoff, "Interior Ballistics of Gun Barrel Systems and of Solid Propellant Rockets", Russian Book published by Oboronghiz in 1962. Abbr translation by Dr V. Nekrassoff available in PicArsn Library 2) A.G. Gorsc, "Powders and Explosives", Mashinostroyeniye, Moscow (1972), p 9(in Russian)... 

Grave, I.P. A Russian baiiistician, born in the 1870 s, who started to teach in the 1900 s at the Imperial Artillery Academy at St Peters-bourg. He published in 1932—38 books on Interior Ballistics in five volumes, which may be considered as an Encyclopedia of Ballistics, He was still active in 1940 as professor in Artillery Academy, He developed in 1916 a type of smokeless proplnt suitable for rockets, but its application was postponed till 1928... 

Ref M.E. Serebriakov, "Vnutrenniayia Bal-listika Stvol nykh Si stem i Porokhovykh Raket (Interior Ballistic of Gun Barrel Systems and Solid Propellant Rockets", Oborongiz. Moskva (1962), pp 15, 19 Sc 23—5. Abbreviated Engl translation by Dr V. A. Nekrassoff, formerly of Aberdeen Proving Ground, Maryland... 

Additives for altering burning rate are always of interest to the propellant formulator in his efforts to meet the ballistic needs of the rocket... 

We gratefully acknowledge the sponsorship of this work by the Ballistics Systems Division and the Rocket Propulsion Laboratory of the U. S. Air Force. Recognition is given to A. J. DiMilo, D. E. Johnson, C. B. Frost, and R. Putnam, who contributed a major portion of the experimental data. 

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