Solid Rocket Propellants

Science and Technology Challenges

Haridwar Singh, Himanshu Shekhar

• Verlag: Royal Society of Chemistry
• Jahr: 2019
• ISBN:
  9781788018081
• Auflage: 1
• Thema: Technology & Engineering
• Thema: Materials Science

Propellants contain considerable chemical energy that can be used in rocket propulsion. Bringing together information on both the theoretical and practical aspects of solid rocket propellants for the first time, this book will find a unique place on the readers' shelf providing the overall picture of solid rocket propulsion technology. Aimed at students, engineers and researchers in the area, the authors have applied their wealth of knowledge regarding formulation, processing and evaluation to provide an up to date and clear text on the subject.

1

The History of Rocketry and The Systems Involved

1.1 History of Rocketry

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Fire is the origin of weapon development in a true sense. The throwing of fire pots, containing flammable materials like naphtha, is reported as far back as 1000 B.C. Although not rockets in a true sense, Archytas, a Greek philosopher, demonstrated the reaction principle in 360 B.C. He filled water in a hollow clay pigeon and set it over fire. The pigeon moved under its own power due to the escape of steam through strategically placed holes. In the first century AD, Hero from Alexandria demonstrated the reaction principle using an aelopile, in which a globe mounted on two central trunions rotates due to passage through tangentially placed exit points. The book by Sir Issac Newton Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) in 1687 resulted in the first scientifically defined reaction principles.

The Chinese were the leaders in the development of firearms. They contributed immensely to both the theoretical and practical development of rocketry. By 200 B.C., the Chinese are believed to have discovered black-powder, while separating gold from silver during a low temperature reaction. They added KNO₃ and sulfur to gold ore but forgot to add charcoal. They added charcoal as the last step. Unknown then, they had made Black-powder, which resulted in a tremendous explosion. Black-powder was, however, not introduced until the 13th century. In 994 A.D., the Chinese developed an attack mechanism based on artillery fire made up of catapulted stones and fire arrows launched by bows. In 1045, a compendium by Tseng Kung-Liang named as “Wu-ching Tsung-Yao” (Complete Compendium of Military Classics) was compiled, which illustrates the use of ballistic fire arrows not launched by bows but by charges of gunpowder. These fire arrows were propelled by ignited gunpowder housed in tube tied to the arrow. These fire arrows were launched in salvos from arrays of cylinders or boxes, which could hold as many as 1000 fire arrows each. In 1500, the Chinese even attempted to propel man with the help of a similar rocket-propelled vehicle, but failed.

The word “Rochetta”, which means “rocket” in English, was used first by an Italian named Muratori in 1379 by the 13th century, the armies of Japan, Korea and India are believed to have acquired a sufficient knowledge of gunpowder-propelled fire arrows. In 1285, the Arabs began using gunpowder-propelled fire arrows in combat. By 1410, briefs on the design of tube-launched military rockets were also published. During the 15th century, French troops used war rockets extensively in their attacks. In 1627, gunpowder was used as a blasting agent for recovering ore in Hungary. During 1670, the British used black powder for copper mining. Indian troops were not far behind in using rockets in battlefields. In 1788, Hyder Ali formed a rocket contingent made up of 1200 men. His son Tipu Sultan used it effectively against the British army in the Battle of Srirangapattam in 1792. The rockets disoriented the British soldiers by sheer numbers, sound and dazzling blue light, even during the night.

In 1804, William Congreve developed a variety of superior rockets with incendiary effects, conical metallic warheads, parachute mounted flares and battlefield messages distribution services. He developed a variety of rockets of different calibers, types and for various purposes. Congreve rockets were successfully used in battles for capturing Callao (1809), Cadiz (1810), Leipzig (1813), Fort McHenry in Baltimore (1814) and Waterloo (1815). In the middle of the 19th century, William Hale developed spin-stabilized rockets for better accuracy. The first use of these rockets took place in Mexican war of 1846–48. Russia test fired rockets in 1817 and their first rocket manufacturing plant was established at St. Petersburg in 1826. In the latter half of the 19th century, significant advances in conventional artillery resulted in the reduced use of rockets in wars.

In 1855, the first two-stage rocket was developed for the transport of heavier cord and in rescue line applications. In 1881, Russian Nikolai Kibalchich is believed to have designed the first rocket-propelled aircraft and the first gimbaled engine. Although unconfirmed, but Peruvian chemical engineer Pedro A. Paulet proposed the first liquid-fueled rocket; he used nitrogen peroxide and gasoline for propulsion. However, by the middle of the 19th century, the limitation of black-powder as a blasting explosive became apparent. In 1846, the Italian professor Sobrero discovered liquid nitroglycerin (NG). A few years later the Swedish inventor, Nobel developed a process for manufacturing NG. Nobel began to license the construction of NG plants, which were built near the site of intended use, as transportation of NG tended to generate a loss of life and property. The Nobel family suffered many setbacks in marketing NG. One of the accidental explosions destroyed the Nobel factory in 1864 and killed Alfred's brother Emil. After another explosion in 1866, which demolished another NG factory, Alfred turned his attention to safety issues for transporting NG. Alfred mixed NG with “Kieselguhr”. This mixture was known as guhr dynamite and was patented in 1867.

Along with NG, the nitration of cellulose to produce nitrocellulose (NC) was being studied by different workers. With the announcement of Schonbem in 1846 (and by Bottger) that NC had been prepared, its utilization began. Many accidents took place during the preparation of NC and many plants were destroyed in France, England and Austria. Abel (1865) showed that through the process of pulping, boiling and washing, the stability of NC could be greatly improved. In 1875, Alfred Nobel discovered that on mixing NC with NG, a gel was formed. This gel was used to produce blasting gelatine. Later in 1888, ballistite, the first smokeless powder consisting of NC, NG, Benzene and camphor was discovered. The British called it “Cordite”. In various forms cordite remained the main propellant of British force until 1930. The British established a cordite factory in India, close to Otty (Arvankadu) to manufacture various types of cordites.

Before WWII, propellants were established mainly for small arms in cannons and for sporting ammunition for civilian uses. The advent of rockets in WWII and the use of extruded double base propellants in rockets as early as the 13th century by the name of “Fire Arrow” propelled by rockets increased their range. In the latter part of the 19th century, the development of artillery with a high accuracy and long range was due to improvements in propellant characteristics, which continue till now. The two main classes of propellants, solid and liquid have some characteristics in common but there are many more that are quite different. Today, hybrid rockets using a liquid oxidizer and a solid fuel, are gaining importance with respect to their high performance and high safety level.

Although a number of improvements in gunpowder were made, it still had many undesirable properties like bright muzzle flash, a large quantity of smoke and hygroscopicity. The solid residue formed was also very corrosive and had to be removed after each firing. The introduction of NC smokeless powder by Vielle in 1886 marked a significant advancement in propellant history. After a few years Nobel introduced NC–NG based double base propellant. As a result of increased research and development activities during WWII, a group of solid propellants called composite propellants emerged. The first composite rocket appeared somewhere during 1945. Since then composite propellants have assumed a major role in the propellant field. Earlier propellants were used mostly for military applications, but the advent of sputnik and explorer satellites opened the way for greater usage of propellants in space. There has been considerable propellant applications for industrial use but when compared to military use, these applications are limited. Oil-well perforating guns, industrial cannons for quarries are a few examples of industrial use. Jet-assisted take-off (JATO) rockets have been introduced for aircrafts.

In the early 20th century, the preparedness for world wars resulted in the introduction of several new technologies in rocketry. The first guided missiles were introduced in the form of the British A.T. (Aerial Target) and the US Kettering Bug. The feasibility of radio guidance was established during this project. The Kettering Bug, a bi-plane bomber, was successfully demonstrated in 1918. However, these could not be placed into production due to the end of the hostilities of WWI. In between the two world wars, the development and evaluation of several rockets, based on solid and liquid fuels continued in different countries, e.g. Larynx, a radio guided mono plane, Queen Bee and Queen Wasp, both radio guided bi-planes (British), GIRD-X and Aviavnito (Russia), Mirak-I (Minimum Rocket–I), Huckel-Winkler-I (powered by liquid oxygen and liquid methane), Repulsor of Germany etc. In fact, major development in this vital field took place in Germany after the establishment of a rocket production facility at Peenemunde and production of the ‘V’ series of rockets. JATO, based on solid and liquid fuels, was developed and introduced by the US During WWII, the US introduced the Bazooka (a rocket-powdered grenade), the Barrage rocket (an air-to-surface missile with many variants like: M-8, super 4.5-incher, spinner, HVSR or high velocity spin-stabilized rocket, Tiny Tim, Bat, T-22, Little Joe, Lark etc.). Parallel to this, the British rocket development program included a finned version of barrage rockets, Snare and winged missile “Stooge”. The Russians deployed their barrage rocket named “Katyusha”. The Japanese developed the surface-to-air missiles Funryu-2 and 4 and the solid propellant-propelled suicide plane “Ohka” during this period. After WWII, the allied forces captured the Peenemunde plant of Germany and further development of rockets were mainly offshoots of the technical expertise and knowledge gained due to the concentrated efforts of Von Braun of Germany.

Conventional propulsion systems based on gasoline or jet fuel need atmospheric air for their operation. However, rocket or gun propellants do not need air because the required oxygen is contained within the propellants. The propellant system is a balanced source of potential energy containing oxidizer and fuel for combustion or conversion to kinetic energy. When the propellant has an oxidizer and a fuel in one molecule, like NC or nitromethane, it is called a “mono-propellant”. However, if the fuel and the oxidizer remain separate and are then mixed in a combustion chamber, they are called “Bi-propellant” systems. Composite propellants have their fuel and oxidizer in separate solid phases. The solid propellants can be broadly classified into three separate groups: (1) homogeneous propellants, containing NC, NG, stabilizer etc. also known as double base propellant (DBP); (2) composite propellants (CP) consist of an oxidizer (AP), a binder (polymeric material) and a metallic fuel (Al); and (3) composite-modified double base (CMDB) propellants take advantages of both the DBP and CP systems.

Solid propellants undergo decomposition by a deflagration process. Sufficient heat is generated above the propellant surface, which is transferred back to the surface by conduction and thereby causes further decomposition of the newly exposed surface. This reaction is self-propagating. Propellants perform their work by the slow liberation of energy characterized by high temperature gases pushing against the surrounding air. High explosives, on the contrary, perform their work by sudden shattering, as in the case of rock breaking. Solid propellants were used in the early rockets and have always been used in guns.

1.2 Spacecrafts and Rockets

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The development of propulsion units for spacecrafts has been inseparable from the development of rockets. Although not starting until the mid-20th century, space vehicle development has in fact surpassed the wartime uses of rockets. The most popular among US space vehicles is the space shuttle approved officially in 1971 as a “Space Transportation System” (STS). The argument put forth during the sanction about its utility was to ferry people and supplies; to act as orbiting scientific laboratory; and to place, repair and recover satellites in orbit. Its first flight took place in 1981. For the upper stage launch system, Centaur and Agena have been developed. Vanguard, started in 1955, placed the first satellite in orbit in 1958 only after several unsuccessful attempts. The Titan rocket was developed by the US as a powerhouse for an ICBM (Intercontinental Ballistic Missile). Titan-II, developed in 1962 as a 2-stage vehicle, was successfully produced. However, obsolescence resulted in diversion of these vehicles for space applications as launch vehicles. Later the Titan-III series and Titan-IV were also developed for specific applications. A similar history surrounds the development of “Thor”, an intermediate range ballistic missile. The US developed it for deployment in England, in 3-stage and 4-stage configurations. Deployment started in 1958 but later on it was diverted to space application and during 1962, it was used for high-altitude tests. Several versions of hybrid launch vehicles by combining different stages of Thor with stages of Vanguard, Delta, Agena were made and used for space applications. Solid fuel rockets “Scout”, instrumental in successful launch of Explorer-9 in February 1961 was grounded by NASA (National Aeronautics and Space Administration) in 1994 after around 118 flights. The development of the Saturn V class of launch vehicles resulted in the successful lunar mission. The 6th Saturn-V propelled Apollo-11 for the first landing of humans on the Moon surface on 20 July 1969. Furthermore, the Saturn class of vehicles was used for the launch of the manned Skylab during 1972–73. The first American satellite, Explorer-I used a Jupiter-C rocket, which was conceived by adding a fourth stage to the Redstone rocket, first launched in 1961. A highly successful but lesser known rocket de...