Rocket

• 1. Ancient Origins And Early Development

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  Gunpowder-powered rockets evolved in medieval China under the Song dynasty by the 13th century. The Song navy used these weapons in a military exercise dated to 1245. Internal-combustion rocket propulsion appeared in a reference from 1264, recording that the ground-rat firework frightened Empress-Mother Gongsheng at a feast held by Emperor Lizong. Rockets were included in the military treatise Huolongjing written by Chinese artillery officer Jiao Yu in the mid-14th century. This text mentions the first known multistage rocket called the fire-dragon issuing from the water. The Mongols adopted Chinese rocket technology and spread the invention via invasions to the Middle East and Europe in the mid-13th century. Between 1270 and 1280 Hasan al-Rammah wrote The Book of Military Horsemanship and Ingenious War Devices containing 107 gunpowder recipes with 22 for rockets. Roger Bacon mentioned firecrackers made in various parts of the world in his Opus Majus of 1267. Konrad Kyeser described rockets in his military treatise Bellifortis around 1405. Giovanni Fontana created rocket-propelled animal figures as a Paduan engineer in 1420. The name rocket comes from the Italian rocchetta meaning bobbin or little spindle due to its shape similarity to thread spools. Leonhard Fronsperger and Conrad Haas adopted the Italian term into German in the mid-16th century while English usage appeared by the early 17th century. Artis Magnae Artilleriae pars prima an important early modern work on rocket artillery was first printed in Amsterdam in 1650.

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• 2. The Space Age Revolution

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  Modern rockets originated in 1926 when Robert Goddard attached a supersonic de Laval nozzle to a high pressure combustion chamber. These nozzles turned hot gas from the combustion chamber into cooler hypersonic highly directed jets more than doubling thrust and raising engine efficiency from 2% to 64%. His use of liquid propellants instead of gunpowder greatly lowered weight and increased effectiveness. In 1943 production of the V-2 rocket began in Germany designed by the Peenemünde Army Research Center with Wernher von Braun serving as technical director. The V-2 became the first artificial object to travel into space by crossing the Kármán line with the vertical launch of MW 18014 on the 20th of June 1944. Doug Millard states the V-2 was a quantum leap of technological change developed with massive resources including grim slave labor conditions. During World War II the Soviet Katyusha rocket launcher used solid chemical propellants for artillery roles while American anti-tank bazooka projectiles also relied on solid fuels. The Americans captured German rocket scientists including Wernher von Braun in 1945 bringing them to the United States as part of Operation Paperclip. Independently in the Soviet Union Sergei Korolev led continued research under his chief designer role from 1907 until 1966. The Cold War saw rapid development particularly in the Soviet Union with vehicles like Vostok Soyuz and Proton alongside American programs such as the X-15. American crewed programs Project Mercury Project Gemini and later Apollo culminated in 1969 with the first crewed landing on the Moon using equipment launched by the Saturn V rocket.

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• 3. Engineering Design And Propulsion Systems

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  Rockets consist of a propellant a place to put propellant such as a propellant tank and a nozzle. They may have one or more rocket engines directional stabilization devices such as fins vernier engines or engine gimbals for thrust vectoring gyroscopes and a structure typically monocoque to hold components together. Rocket engines employ jet propulsion principles emitting hot exhaust gas through combustion chambers. Most current rockets are chemically powered using internal combustion engines or decomposing monopropellants. A rocket engine can use gas propellants solid propellant liquid propellant or hybrid mixtures of both. Some rockets use heat or pressure supplied from sources other than chemical reactions such as steam rockets solar thermal rockets nuclear thermal rocket engines or simple pressurized rockets like water rockets. For smaller low performance rockets such as attitude control thrusters where high performance is less necessary a pressurised fluid escapes spacecraft through a propelling nozzle. The shape of the nozzle generates force by directing exhaust gas along the axis of the rocket. In properly designed engines flow reaches Mach 1 at the throat before accelerating further beyond the bell shaped expansion part giving additional thrust. Liquid propellants generally have densities similar to water with notable exceptions of liquid hydrogen and liquid methane able to use lightweight low pressure tanks running high-performance turbopumps forcing propellant into combustion chambers.

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• 4. Physics Of Flight And Performance

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  The delta-v capacity of a rocket represents theoretical total change in velocity achievable without external interference like air drag or gravity. When launched from Earth practical delta-vs for single rockets carrying payloads can reach several km/s while some theoretical designs exceed 9 km/s. The required delta-v to launch from Earth surface to low Earth orbit is about 9.7 km/s leaving vehicle with sideways speed around 7.8 km/s at altitude near 200 km. Almost all launch vehicle mass consists of propellant making mass ratio critical for good performance since it indicates lightweight construction. Rockets achieve highest thrust-to-weight ratios among engine types helping vehicles attain high mass ratios improving flight performance. For example Soyuz escape system produces 20 g peak acceleration. Maximum speeds theoretically limited only by light speed but payload decreases geometrically with each extra stage needed while additional delta-v remains additive. Staging solves velocity problems where single-stage-to-orbit has not been achieved yet. First stage of Saturn V carried weight of upper stages achieving mass ratio about 10 with specific impulse of 263 seconds giving delta-v around 5.9 km/s whereas 9.4 km/s needed to achieve orbit with losses allowed. Energy efficiency reaches peak around 100% when vehicle travels exactly same speed as exhaust emitted taking away zero energy.

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• 5. Military Applications And Ballistics

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  Some military weapons use rockets to propel warheads to targets generally referred to as missiles when weapon has guidance system or as rocket if unguided. Anti-tank and anti-aircraft missiles engage targets at high speed over several miles range while intercontinental ballistic missiles deliver multiple nuclear warheads from thousands of miles. Anti-ballistic missiles try to stop incoming threats. Reconnaissance rockets like Ping-Pong rocket were tested but never came into wide military use. Sounding rockets carry instruments taking readings from 50 to 1,200 kilometers above Earth surface. First images of Earth from space obtained from V-2 rocket in 1946 flight number 13. Rocket engines propel rocket sleds along rails at extremely high speeds reaching world record Mach 8.5. Spacecraft delivered into orbital trajectories become artificial satellites used for many commercial purposes. Rockets remain only way to launch spacecraft into orbit and beyond accelerating them rapidly when changing orbits or de-orbiting for landing. Some crewed rockets notably Saturn V and Soyuz have launch escape systems pulling crewed capsule away from main vehicle toward safety moments after failure. Safety Assurance System successfully pulled L3 capsule away during three of four failed launches of Soviet Moon rocket N1 vehicles 3L 5L and 7L. Successful escape occurred when Soyuz T-10 exploded on pad en route to Salyut 7 space station.

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• 6. Economics And Modern Commercialization

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  Costs of rockets divide roughly into propellant costs dry mass production expenses support equipment and facility fees. Most takeoff mass is normally propellant though seldom more than few times expensive per kilogram as gasoline was about $1 or less by 2009. Liquid oxygen cost around $1 per liter while liquid hydrogen reached $10 per liter making Space Shuttle 2009 liquid propellant expense approximately $1.4 million per launch costing $450 million total. Even non-propellant dry mass often between 5% to 20% of total mass dominates expenses with hardware performance reaching $2,000 to $10,000 plus per kilogram of dry weight primarily from engineering fabrication testing. Raw materials amount typically around 2% of total expense. Extreme performance requirements correlate with high cost including intensive quality control ensuring reliability despite limited safety factors allowable for weight reasons. Components produced in small numbers prevent amortization of research development and facility costs over mass production seen in pedestrian manufacturing. Among liquid-fueled rockets complexity influenced by lightweight hardware needs since pressure-fed engines have two orders magnitude lesser part count than pump-fed engines but lead to more weight needing greater tank pressure mostly used just in small maneuvering thrusters. Since early 2010s new private options emerged bringing substantial price pressure into existing market. Proposed methods include mass-producing simple rockets large quantities developing reusable rockets flying frequently to amortize up-front expense reducing rocket performance requirements constructing non-rocket spacelaunch systems.

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