Combustion

Part 11 - Early Rockets

Rockets may have been first launched in China 1232 CE, when records described fire arrows and 'iron pots' exploding upon impact.

Rockets are mentioned in the Fire Drake Manual, written by the Chinese artillery officer Jiao Yu in the mid-14th century. This text mentions the first known multistage rocket.

The Chinese fire arrow was adopted by the Mongols in northern China, and possibly spread to Europe following Mongol invasions in the mid 13th century.   Mongol mercenaries are recorded to have used hand held rockets in India in 1300 and by mid-14th century Indians were also using rockets in warfare.

Between 1270 and 1280, Hasan al-Rammah wrote The Book of Military Horsemanship and Ingenious War Devices, which included 107 gunpowder recipes, 22 of which were for rockets.

In Europe, Roger Bacon mentioned gunpowder in his Opus Majus of 1267 and Konrad Kyeser described rockets in his military treatise Bellifortis around 1405.   Jean Froissart (1337 to 1405) suggested launching rockets through tubes, (the forerunner of the modern bazooka) so that they could make more accurate flights.

The English name Rocket comes from the Italian rocchetta, meaning "little spindle", because of its similar shape to the bobbin or spool used to hold thread fed to a spinning wheel.

Kazimierz Siemienowicz published "The Complete Art of Artillery" in 1650 Amsterdam , and for over two centuries, it was the basic artillery manual used in Europe. The book provided designs for creating rockets, fireballs, and other pyrotechnic devices. It contained a large chapter on caliber, construction, production and properties of rockets (for both military and civil purposes), including multi-stage rockets, batteries of rockets, and rockets with delta wing stabilizers (instead of the common guiding rods).

During the latter part of the 17th century, the English scientist Sir Isaac Newton established the scientific foundations for modern rocketry. Newton organized his understanding of physical motion into three scientific laws. The laws explain how rockets work and why they are able to work in the vacuum of outer space. Newton's laws soon began to have a practical impact on the design of rockets. About 1720, a Dutch professor, Willem Gravesande, built model cars propelled by jets of steam. Rocket experimenters in Germany and Russia began working with rockets with a mass of more than 45 kilograms. Some of these rockets were so powerful that their escaping exhaust flames bored deep holes in the ground even before lift-off.

In 1792, the first iron-cased rockets were developed by Tipu Sultan (the ruler of the Kingdom of Mysore, in India) and used against the larger British East India Company forces. The Mysore rockets used iron tubes to hold the propellant greater thrust and longer range (up to 2 km).

From 1801, based on the Mysore rockets, William Congreve developed a strong iron tube with a conical nose and a new propellant mixture and rocket motor. The first Congreve rocket weighed about 32 pounds (14.5 kilograms) and the Royal Arsenal demonstrated solid-fuel rockets in 1805. The rockets were used effectively during the Napoleonic Wars and the War of 1812 against the USA.

At the Battle of Baltimore in 1814, the rockets fired on Fort McHenry by the rocket vessel HMS Erebus were the source of the rockets' red glare described by Francis Scott Key in "The Star-Spangled Banner".

In 1815, Alexander Dmitrievich Zasyadko developed military rocket-launching platforms to permit firing salvos of 6 rockets at a time.

These rockets were not accurate as they tended to veer sharply away from the intended course. Congreve reduced this partially by attaching a long stick to the end of a rocket.

In 1844, William Hale greatly improved accuracy when he added small vanes in the exhaust at the bottom of the rocket, causing it to spin along its axis-of-travel like a bullet from a rifled barrel. In 1865, artillery Colonel Edward Mounier Boxer patented a two stage rocket that was mainly used to throw a line for marine rescue. 

The devastating nature of war rockets was not their accuracy or power, but their numbers. During a typical siege, thousands of them might be fired at the enemy.

Rockets continued to be used alongside muzzle loading cannon until the Austrian rocket artillery was out-ranged by the newly designed Prussian breech-loading cannon with rifled barrels and exploding warheads. 

In 1903, a Russian schoolteacher, Konstantin Tsiolkovsky (1857-1935), inspired by Jules Verne and H. G. Wells, published The Exploration of Cosmic Space by Means of Reaction Devices, the first serious scientific work on space travel using rockets. Tsiolkovsky stated that the speed and range of a rocket were limited only by the exhaust velocity of escaping gases and identified the Tsiolkovsky rocket equation as the principle that governs rocket propulsion. This relates rocket mass, acceleration and speed as well as the maximum speed of gases leaving the combustion chamber and how much propellant remains. He also suggested using liquid propellants, including liquid hydrogen and oxygen, as fuel to achieve greater range.  In 1929, Tsiolkovsky also published a theory of multistage rockets and has been internationally recognized for his visionary ideas and careful research.

Unlike most other engines that burn atmospheric oxygen with a fuel, rockets carry oxygen with them so they will propel a vehicle in the vacuum of space. Gunpowder contains carbon and sulphur as fuel and uses the oxygen in potassium nitrate which is a chemical compound KNO3. Some modern rocket use liquid oxygen and liquid hydrogen.

To exist as a liquid, hydrogen must be cooled below its critical point of 33 K. However, for it to be in a fully liquid state at atmospheric pressure, it must be cooled to 20.28 K (−252.87 °C; −423.17 °F).  Like any gas, storing hydrogen as liquid takes less space than storing it as a gas at normal temperature and pressure. However, the liquid density is very low compared to other common fuels. Once liquefied, it can be maintained as a liquid in pressurized and thermally insulated containers.

In 1912, Robert Esnault-Pelterie published a lecture on rocket theory and interplanetary travel. He independently derived Tsiolkovsky's rocket equation and calculated the energy required to make round trips to the Moon and planets. He also suggested using atomic power to power a jet drive.

In 1912, Robert Goddard, inspired by H.G. Wells, independently developed the mathematics of rocket flight. In 1914 he patented the ideas of:- burning the fuel in a small combustion chamber, instead of making the entire propellant container capable of withstanding the high pressures; arranging rockets in stages so that later stages did not carry the weight of empty fuel containers; improving efficiency by increasing the exhaust velocity above the speed of sound with the use of a De Laval nozzle.

A de Laval nozzle (or convergent-divergent nozzle) is a tube that is a carefully balanced, asymmetric hourglass shape that converts the heat energy of a hot gas, flowing through it, into kinetic energy, accelerating the gas to supersonic speed in the axial (thrust) direction.

Yves Le Prieur, a French naval officer during World War I, developed solid-fuel, air-to-air rockets as a way to destroy observation balloons used by German artillery. These were steel-tipped, gun powder incendiary rockets, the first ever fired from aircraft in battle.

Eight electrically fired rockets were mounted on the inter-plane struts of a Nieuport aircraft and electrically fired. When the balloon crew spotted an approaching aircraft they ordered the ground crews to winch the balloon down because, at close range the rockets were deadly. Belgian ace Willy Coppens claimed dozens of balloon kills.