View source for Rocket

{{Short description|Vehicle propelled by a reaction gas engine}}
{{pp-vandalism|small=yes}}
{{other uses}}
{{Use British English|date=February 2019}}
[[File:Soyuz TMA-9 launch.jpg|alt=|thumb|upright|A [[Soyuz-FG]] rocket launches from "[[Gagarin's Start]]" (Site 1/5), [[Baikonur Cosmodrome]] ]]
A '''rocket''' (from {{langx|it|rocchetto||'bobbin/spool'}}, and so named for its shape)<noinclude>{{#tag:ref|English ''rocket'', first attested in 1566 (OED), adopted from the Italian term, given due to the similarity in shape to the bobbin or spool used to hold the thread from a spinning wheel. The modern Italian term is ''[[:wikt:razzo|razzo]]''.|group=nb}}</noinclude><ref name="Bernhard">{{cite book|first1=Jim|last1=Bernhard|title=Porcupine, Picayune, & Post: How Newspapers Get Their Names|url=https://archive.org/details/porcupinepicayun00bern_0|url-access=registration|publisher=University of Missouri Press|year=2007|isbn=978-0-8262-6601-9|access-date=28 May 2016|page=[https://archive.org/details/porcupinepicayun00bern_0/page/126 126]}}</ref> is a [[vehicle]] that uses [[jet propulsion]] to [[Acceleration|accelerate]] without using any surrounding [[Atmosphere of Earth|air]]. A [[rocket engine]] produces thrust by [[Reaction (physics)|reaction]] to exhaust expelled at high speed.<ref name="RPE7">{{cite book|first1=George P.|last1=Sutton|first2=Oscar|last2=Biblarz|title=Rocket Propulsion Elements|url=https://books.google.com/books?id=LQbDOxg3XZcC|publisher=John Wiley & Sons|date=2001|isbn=978-0-471-32642-7|access-date=28 May 2016|url-status=live|archive-url=https://web.archive.org/web/20140112033956/http://books.google.com/books?id=LQbDOxg3XZcC|archive-date=12 January 2014}}</ref> Rocket engines work entirely from [[rocket propellant|propellant]] carried within the vehicle; therefore a rocket can fly in the [[vacuum]] of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere.

[[Multistage rocket]]s are capable of attaining [[escape velocity]] from Earth and therefore can achieve unlimited maximum altitude. Compared with [[Airbreathing jet engine|airbreathing engines]], rockets are lightweight and powerful and capable of generating large [[acceleration]]s. To control their flight, rockets rely on [[momentum]], [[airfoils]], [[Reaction control system|auxiliary reaction engines]], [[gimballed thrust]], [[Reaction wheel|momentum wheels]], [[Thrust vectoring|deflection of the exhaust stream]], propellant flow, [[Spin-stabilisation|spin]], or [[gravity]].

Rockets for military and recreational uses date back to at least 13th-century [[China]].<ref name="NASAEARLY">{{cite web |url=http://history.msfc.nasa.gov/rocketry/tl1.html |title=Rockets in Ancient Times (100 B.C. to 17th Century) |access-date=2009-06-28 |publisher=NASA |work=A Timeline of Rocket History |author=MSFC History Office |url-status=dead |archive-url=https://web.archive.org/web/20090709042712/http://history.msfc.nasa.gov/rocketry/tl1.html |archive-date=2009-07-09 }}</ref> Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the [[Space Age]], including [[Apollo 11|setting foot on the Moon]]. Rockets are now used for [[fireworks]], [[missile]]s and other [[weapon]]ry, [[ejection seat]]s, [[launch vehicle]]s for [[artificial satellite]]s, [[human spaceflight]], and [[space exploration]].

[[Chemical rocket]]s are the most common type of high power rocket, typically creating a high speed exhaust by the [[combustion]] of [[rocket propellant|fuel]] with an [[oxidizer]]. The stored propellant can be a simple pressurized gas or a single [[liquid fuel]] that disassociates in the presence of a catalyst ([[monopropellant rocket|monopropellant]]), two liquids that spontaneously react on contact ([[hypergolic propellant]]s), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most [[liquid-propellant rocket]]s), a solid combination of fuel with oxidizer ([[Solid-fuel rocket|solid fuel]]), or solid fuel with liquid or gaseous oxidizer ([[Hybrid rocket|hybrid propellant system]]). Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks.{{Citation needed|date=January 2022}}

==History==

{{main|History of rockets}}
{{further|Timeline of rocket and missile technology}}

[[File:Oldest depiction of rocket arrows.jpg|thumb|upright|Rocket arrows depicted in the ''[[Huolongjing]]'': "fire arrow", "dragon-shaped arrow frame", and a "complete fire arrow"]] In China, [[gunpowder]]-powered rockets evolved in medieval China under the [[Song dynasty]] by the 13th century. They also developed an early form of [[multiple rocket launcher]] during this time. The Mongols adopted Chinese rocket technology and the invention spread via the [[Mongol invasions]] to the Middle East and to Europe in the mid-13th century.<ref>{{cite web |quote=Rockets appear in Arab literature in 1258 A.D., describing Mongol invaders' use of them on February 15 to capture the city of Baghdad |url= http://science.ksc.nasa.gov/history/rocket-history.txt |url-status=dead|title= A brief history of rocketry|work= NASA Spacelink|access-date= 2006-08-19|archive-url= https://web.archive.org/web/20060805203537/http://science.ksc.nasa.gov/history/rocket-history.txt|archive-date= 2006-08-05}}</ref> According to Joseph Needham, the Song navy used rockets in a [[military exercise]] dated to 1245. Internal-combustion rocket propulsion is mentioned in a reference to 1264, recording that the "ground-rat", a type of [[firework]], had frightened the Empress-Mother [[Gongsheng]] at a feast held in her honor by her son the [[Emperor Lizong]].<ref>{{cite book |last = Crosby |first = Alfred W. |title = Throwing Fire: Projectile Technology Through History |year = 2002 |publisher = Cambridge University Press |location = Cambridge |isbn = 978-0-521-79158-8 |pages = 100–103}}</ref> Subsequently, rockets are included in the military treatise ''[[Huolongjing]]'', also known as 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 [[Huolongchushui|'fire-dragon issuing from the water']] (Huo long chu shui), thought to have been used by the Chinese navy.<ref name="Needham volume 5 part 7 510">Needham, Volume 5, Part 7, 510.</ref> 

Medieval and early modern rockets were used militarily as [[Incendiary device|incendiary weapons]] in [[siege]]s. Between 1270 and 1280, Hasan al-Rammah wrote ''al-furusiyyah wa al-manasib al-harbiyya'' (''The Book of Military Horsemanship and Ingenious War Devices''), which included 107 gunpowder recipes, 22 of them for rockets.<ref name=Gunpowder>{{cite web |last= Hassan |first= Ahmad Y |url =http://www.history-science-technology.com/Articles/articles%202.htm |title= Gunpowder Composition for Rockets and Cannon in Arabic Military Treatises In Thirteenth and Fourteenth Centuries |access-date= March 29, 2008 |author-link= Ahmad Y Hassan |work= History of Science and Technology in Islam |url-status=dead |archive-url= https://web.archive.org/web/20080226105129/http://www.history-science-technology.com/Articles/articles%202.htm |archive-date= February 26, 2008 }}</ref><ref>{{cite web |last= Hassan |first= Ahmad Y |url= http://www.history-science-technology.com/Articles/articles%2072.htm |title= Transfer Of Islamic Technology To The West, Part III: Technology Transfer in the Chemical Industries |access-date= 2008-03-29 |author-link= Ahmad Y Hassan |work= History of Science and Technology in Islam |url-status=dead |archive-url= https://web.archive.org/web/20080309003120/http://www.history-science-technology.com/Articles/articles%2072.htm |archive-date= March 9, 2008 }}</ref> In Europe, [[Roger Bacon]] mentioned firecrackers made in various parts of the world in the ''[[Opus Majus]]'' of 1267. Between 1280 and 1300, the [[Liber Ignium]] gave instructions for constructing devices that are similar to firecrackers based on second hand accounts.<ref>{{cite journal | url=https://www.jstor.org/stable/44230626 | jstor=44230626 | title='The Soul of Artillery': Congreve's Rockets and Their Effectiveness in Warfare | last1=McCaig | first1=A. D. | journal=Journal of the Society for Army Historical Research | year=2000 | volume=78 | issue=316 | pages=252–263 }}</ref> [[Konrad Kyeser]] described rockets in his military treatise ''[[Bellifortis]]'' around 1405.<ref>{{cite book|last1= Riper|first1= A. Bowdoin Van|title= Rockets and missiles : the life story of a technology|date= 2004|publisher= Greenwood Press|location= Westport|isbn= 978-0-313-32795-7|page= 10}}</ref> [[Giovanni Fontana (engineer)|Giovanni Fontana]], a [[Padua|Paduan]] engineer in 1420, created rocket-propelled animal figures.<ref>{{Citation |last=Grafton |first=Anthony |title=The Devil as Automaton |date=2007 |work=Genesis Redux |pages=46–62 |url=http://dx.doi.org/10.7208/chicago/9780226720838.003.0003 |access-date=2024-02-18 |publisher=University of Chicago Press |doi=10.7208/chicago/9780226720838.003.0003 |isbn=978-0-226-72081-4}}</ref><ref>{{Cite book |last1=Battisti |first1=Eugenio |title=Le macchine cifrate di Giovanni Fontana: con la riproduzione del Cod. icon. 242 della Bayerische Staatsbibliothek di Monaco di Baviera e la decrittazione di esso e del Cod. lat. nouv. acq. 635 della Bibliothèque nationale di Parigi |last2=Saccaro Del Buffa Battisti |first2=Giuseppa |last3=Fontana |first3=Giovanni |date=1984 |publisher=Arcadia Edizioni |isbn=978-88-85684-06-5 |location=Milano}}</ref>

The name "rocket" comes from the [[Italian language|Italian]] ''rocchetta'', meaning "bobbin" or "little spindle", given due to the similarity in shape to the bobbin or spool  used to hold the  thread from a spinning wheel. [[Leonhard Fronsperger]] and [[Conrad Haas]] adopted the Italian term into German in the mid-16th century; "rocket" appears in English by the early 17th century.<ref name="Bernhard" /> ''Artis Magnae Artilleriae pars prima'', an important early modern work on [[rocket artillery]], by [[Casimir Siemienowicz]],  was first printed in [[Amsterdam]] in 1650.

[[File:Rocket warfare.jpg|thumb|left|[[Mysorean rockets]] and [[rocket artillery]] used to defeat an East India Company battalion during the Battle of Guntur]]
The [[Mysorean rockets]] were the first successful iron-cased rockets, developed in the late 18th century in the [[Kingdom of Mysore]] (part of present-day India) under the rule of [[Hyder Ali]].<ref>{{Cite encyclopedia|url= https://www.britannica.com/technology/rocket-and-missile-system|title= rocket and missile system {{!}} weapons system|encyclopedia= Encyclopædia Britannica |edition=Online |access-date= 2017-10-29|url-status=live|archive-url= https://web.archive.org/web/20171031034251/https://www.britannica.com/technology/rocket-and-missile-system|archive-date= 2017-10-31}}</ref> 

[[File:William Congreve at Copenhagen 1807.jpg|thumb|upright| [[Sir William Congreve, 2nd Baronet|William Congreve]] at the [[Battle of Copenhagen (1807)|bombardment of Copenhagen]] (1807) during the [[Napoleonic Wars]]]]
The [[Congreve rocket]] was a British weapon designed and developed by [[Sir William Congreve, 2nd Baronet|Sir William Congreve]] in 1804. This rocket was based directly on the Mysorean rockets, used compressed powder and was fielded in the [[Napoleonic Wars]]. It was Congreve rockets to which [[Francis Scott Key]] was referring, when he wrote of the "rockets' red glare" while held captive on a British ship that was laying siege to [[Fort McHenry]] in 1814.<ref>{{cite web| url = http://www.airspacemag.com/history-of-flight/rockets-inspired-francis-scott-key-180952399/| title = The Rockets That Inspired Francis Scott Key |work=Air & Space Magazine |last=Winter |first=Frank |date=September 2014 |access-date=22 August 2022}}</ref> Together, the Mysorean and British innovations increased the effective range of military rockets from {{convert|100|to|2000|yd}}.

The first mathematical treatment of the dynamics of rocket propulsion is due to [[William Moore (British mathematician)|William Moore]] (1813). In 1814, Congreve published a book in which he discussed the use of multiple rocket launching apparatus.<ref>{{cite web|url=https://mca-marines.org/blog/gazette/mlrs-and-maneuver-warfare/|title=MLRS and Maneuver Warfare |last=Morris |first=Charles W. |publisher=Marine Corps Association |access-date=22 August 2022}}</ref><ref>{{cite book |url=https://www.gutenberg.org/files/57791/57791-0.txt |title=The Details of the Rocket System |last=Congreve |first=William |orig-date=1814 |date=2018 |publisher=Project Gutenberg}}</ref> In 1815 [[Alexander Dmitrievich Zasyadko]] constructed rocket-launching platforms, which allowed rockets to be fired in [[salvo]]s (6 rockets at a time), and gun-laying devices. [[William Hale (British inventor)|William Hale]] in 1844 greatly increased the accuracy of rocket artillery. [[Edward Mounier Boxer]] further improved the Congreve rocket in 1865.

[[William Leitch (scientist)|William Leitch]] first proposed the concept of using rockets to enable human spaceflight in 1861. Leitch's rocket spaceflight description was first provided in his 1861 essay "A Journey Through Space", which was later published in his book ''God's Glory in the Heavens'' (1862).<ref>{{cite book |last1=Leitch |first1=William |title=God's Glory in the Heavens |date=1862 |url=https://books.google.com/books?id=vuAUAQAAMAAJ }}</ref> [[Konstantin Tsiolkovsky]] later (in 1903) also conceived this idea, and extensively developed a body of theory that has provided the foundation for subsequent spaceflight development.

The British [[Royal Flying Corps]] designed a guided rocket during [[World War I]]. [[Archibald Low]] stated "...in 1917 the [[British unmanned aerial vehicles of World War I|Experimental Works]] designed an electrically steered rocket…  Rocket experiments were conducted under my own patents with the help of [[Frank Arthur Brock|Cdr. Brock]]."<ref>'Flight  3 October 1952,  [[Archibald Low|A. M. Low]], "'The First Guided Missile'   p. 436</ref> The patent "Improvements in Rockets" was raised in July 1918 but not published until February 1923 for security reasons. Firing and guidance controls could be either wire or wireless. The propulsion and guidance rocket eflux emerged from the deflecting cowl at the nose.

[[File:Goddard and Rocket.jpg|thumb|left|upright|Robert Goddard with a liquid oxygen-gasoline rocket (1926)]]
In 1920, Professor [[Robert H. Goddard|Robert Goddard]] of [[Clark University]] published proposed improvements to rocket technology in ''[[A Method of Reaching Extreme Altitudes]]''.<ref name=goddard/>  In 1923, [[Hermann Oberth]] (1894–1989) published ''[[Die Rakete zu den Planetenräumen]]'' (''The Rocket into Planetary Space''). Modern rockets originated in 1926 when Goddard attached a [[supersonic]] ([[de Laval nozzle|de Laval]]) nozzle to a high pressure [[combustion chamber]]. These nozzles turn the hot gas from the combustion chamber into a cooler, [[hypersonic]], highly directed jet of gas, more than doubling the thrust and raising the engine efficiency from 2% to 64%.<ref name=goddard/> His use of [[liquid propellant]]s instead of [[gunpowder]] greatly lowered the weight and increased the effectiveness of rockets.

[[File:RIAN archive 303890 A battery of Katyusha during the 1941-1945 Great Patriotic War.jpg|thumb|A battery of Soviet [[Katyusha rocket launchers]] fires at German forces during the [[Battle of Stalingrad]], 6 October 1942]]
In 1921, the [[Soviet]] research and development laboratory [[Gas Dynamics Laboratory]] began developing [[solid-propellant rocket]]s, which resulted in the first launch in 1928, which flew for approximately 1,300 metres.<ref name="RSB_GDL">{{cite web |last1=Zak |first1=Anatoly |title=Gas Dynamics Laboratory |url=http://www.russianspaceweb.com/gdl.html |website=Russian Space Web |access-date=29 May 2022}}</ref> These rockets were used in 1931 for the world's first successful use of rockets for [[jet-assisted takeoff]] of aircraft<ref name="Glushko">{{cite book |last1=Glushko |first1=Valentin |title=Developments of Rocketry and Space Technology in the USSR |date=1973 |publisher=Novosti Press Pub. House |page=7 |url=https://www.amazon.com/Development-rocketry-space-technology-USSR/dp/B0006CHI4I}}</ref> and became the prototypes for the [[Katyusha rocket launcher]],<ref name="Ezo_Katyusha">{{cite web |title=Katyusha rocket launcher. Weapon of Victory: multiple launch rocket system 'Katyusha' |url=https://ezoteriker.ru/en/reaktivnyi-minomet-katyusha-oruzhie-pobedy-reaktivnaya-sistema-zalpovogo-ognya/ |website=ezoteriker |access-date=5 June 2022}}</ref> which were used during [[World War II]].

In 1929, [[Fritz Lang]]'s German science fiction film ''[[Woman in the Moon]]'' was released. It showcased the use of a [[multi-stage rocket]], and also pioneered the concept of a rocket [[launch pad]] (a rocket standing upright against a tall building before launch having been slowly rolled into place) and the rocket-launch [[countdown]] clock.<ref name="Lang profile">[https://www.sky.com/watch/title/series/299ce04f-6462-482a-8973-02d22bacc3d3/the-directors/episodes/season-1/episode-6 "The Directors (Fritz Lang)"]. [[Sky Arts]]. Season 1, episode 6. 2018</ref><ref>{{cite journal | last = Weide| first= Robert | date = Summer 2012 | title = The Outer Limits | journal = DGA Quarterly | location = Los Angeles, California  | pages = 64–71  | publisher = Directors Guild of America, Inc. | url=http://www.dga.org/Craft/DGAQ/All-Articles/1203-Summer-2012/Photo-Essay-Outer-Limits.aspx
}} A gallery of behind-the-scenes shots of movies featuring space travel or aliens. Page 68, photo caption: "Directed by Fritz Lang (third from right), the silent film "[[Woman in the Moon]]" (1929) is considered one of the first serious science fiction films and invented the countdown before the launch of a rocket. Many of the basics of space travel were presented to a mass audience for the first time."</ref> ''[[The Guardian]]'' film critic Stephen Armstrong states Lang "created the rocket industry".<ref name="Lang profile"/> Lang was inspired by the 1923 book ''The Rocket into Interplanetary Space'' by Hermann Oberth, who became the film's scientific adviser and later an important figure in the team that developed the V-2 rocket.<ref>{{cite news |title=Woman in the Moon – Philip French on Fritz Lang's handsomely restored moon-mission yarn |url=https://www.theguardian.com/film/2014/nov/23/fritz-lang-woman-in-the-moon-dvd-review-philip-french |access-date=24 July 2022 |work=The Guardian}}</ref> The film was thought to be so realistic that it was banned by the Nazis when they came to power for fear it would reveal secrets about the V-2 rockets.<ref>{{cite news |title=Watch the Silent Film that Brought Rocket Science to the Masses |url=https://www.vice.com/en/article/paywwy/watch-the-silent-film-that-brought-rocket-science-to-the-masses |access-date=24 July 2022 |work=Vice}}</ref>

[[File:Bundesarchiv Bild 141-1880, Peenemünde, Start einer V2.jpg|thumb|left|upright|[[V-2 rocket]] launched from [[Test Stand VII]], summer of 1943]]
In 1943 production of the [[V-2 rocket]] began in Germany. It was designed by the [[Peenemünde Army Research Center]] with [[Wernher von Braun]] serving as the technical director.<ref>Ordway, Frederick I., III.; Sharpe, Mitchell R. ''The Rocket Team''. Apogee Books Space Series 36. p. 38.</ref> 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 20 June 1944.<ref>{{cite book |title=The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era |url=https://archive.org/details/isbn_9780029228951 |url-access=registration |last=Neufeld |first=Michael J. |publisher=The Free Press |year=1995 |location=New York |pages=[https://archive.org/details/isbn_9780029228951/page/158 158], 160–162, 190 |isbn=9780029228951 |access-date=15 November 2019 |archive-url=https://web.archive.org/web/20191028112702/https://archive.org/details/isbn_9780029228951 |archive-date=28 October 2019 |url-status=live }}</ref> Doug Millard, space historian and curator of space technology at the [[Science Museum, London]], where a V-2 is exhibited in the main exhibition hall, states: "The V-2 was a quantum leap of technological change. We got to the Moon using V-2 technology but this was technology that was developed with massive resources, including some particularly grim ones. The V-2 programme was hugely expensive in terms of lives, with the Nazis using slave labour to manufacture these rockets".<ref name="Space age launch" >{{cite news |first=Richard |last=Hollingham|title=V2: The Nazi rocket that launched the space age |url=https://www.bbc.com/future/article/20140905-the-nazis-space-age-rocket |date=8 September 2014|access-date=26 February 2023 |publisher=BBC}}</ref> In parallel with the German [[guided-missile]] programme, rockets were also used on [[aircraft]], either for assisting horizontal take-off ([[JATO|RATO]]), vertical take-off ([[Bachem Ba 349]] "Natter") or for powering them ([[Me 163]], see [[list of World War II guided missiles of Germany]]). The Allies' rocket programs were less technological, relying mostly on unguided missiles like the Soviet [[Katyusha rocket launcher|Katyusha rocket]] in the artillery role, and the American anti tank [[bazooka]] projectile. These used solid chemical propellants.

The Americans captured a large number of German [[rocket scientist]]s, including Wernher von Braun, in 1945, and brought them to the United States as part of [[Operation Paperclip]]. After World War II scientists used rockets to study high-altitude conditions, by radio [[telemetry]] of temperature and pressure of the atmosphere, detection of [[cosmic rays]], and further techniques; note too the [[Bell X-1]], the first crewed vehicle to break the [[sound barrier]] (1947). Independently, in the  [[Soviet space program|Soviet Union's space program]] research continued under the [[leadership]] of the chief designer [[Sergei Korolev]] (1907–1966).

During the [[Cold War]] rockets became extremely important militarily with the development of modern [[intercontinental ballistic missiles]] (ICBMs). The 1960s saw rapid development of rocket technology, particularly in the Soviet Union ([[Vostok rocket|Vostok]], [[Soyuz (rocket family)|Soyuz]], [[Proton rocket|Proton]]) and in the United States (e.g. the [[X-15]]). Rockets came into use for [[space exploration]]. American crewed programs ([[Project Mercury]], [[Project Gemini]] and later the [[Apollo programme]]) culminated in 1969 with the first crewed  [[Moon landing|landing on the Moon]] – using equipment launched by the [[Saturn V]] rocket.

==Types==
;Vehicle configurations
[[File:Apollo 15 launch.ogv|thumb|Launch of [[Apollo 15]] [[Saturn V]] rocket: ''T'' − 30 s through ''T'' + 40 s]]
Rocket vehicles are often constructed in the archetypal tall thin "rocket" shape that takes off vertically, but there are actually many different types of rockets including:<ref>{{cite web |url=http://www.hq.nasa.gov/pao/History/conghand/vehicles.htm |title=NASA History: Rocket vehicles |publisher=Hq.nasa.gov |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20130125030055/http://www.hq.nasa.gov/pao/History/conghand/vehicles.htm |archive-date=2013-01-25 }}</ref>
* tiny models such as [[balloon rocket]]s, [[water rocket]]s, [[skyrocket]]s or [[model rocket|small solid rockets]] that can be purchased at a [[hobby store]]
* [[missile]]s
* [[launch vehicle|space rockets]] such as the enormous [[Saturn V]] used for the [[Apollo program]]
* [[rocket car]]s
* rocket bike<ref>{{cite news|url=https://www.bbc.co.uk/news/technology-30007505|title=Rocket bicycle sets 207mph speed record By Leo Kelion|work=BBC News|date=2013-11-11|access-date=2014-11-11|url-status=live|archive-url=https://web.archive.org/web/20141111150526/http://www.bbc.co.uk/news/technology-30007505|archive-date=2014-11-11|last1=Kelion|first1=Leo}}</ref>
* [[rocket-powered aircraft]] (including rocket-assisted takeoff of conventional aircraft – [[JATO|RATO]])
* [[rocket sled]]s
* [[Opel-RAK|rocket trains]]
* [[VA-111 Shkval|rocket torpedoes]]<ref>{{cite book|last1=Polmar|first1=Norman|last2=Moore|first2=Kenneth J.|title=Cold War submarines : the design and construction of U.S. and Soviet submarines|date=2004|publisher=Brassey's|location=Washington, DC|isbn=978-1-57488-594-1|page=304}}</ref><ref>{{cite book|last1=III|first1=compiled by A.D. Baker|title=The Naval Institute guide to combat fleets of the world 2000–2001 : their ships, aircraft, and systems|date=2000|publisher=Naval Institute Press|location=Annapolis, MD|isbn=978-1-55750-197-4|page=581}}</ref>
* rocket-powered [[jet pack]]s<ref>{{cite web |url=http://www.rocketman.org |title=The Rocketman |publisher=The Rocketman |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20100213121923/http://www.rocketman.org/ |archive-date=2010-02-13 }}</ref>
* rapid escape systems such as [[ejection seat]]s and [[launch escape system]]s
* [[space probe]]s
{{clear}}

==Design==
A rocket design can be as simple as a cardboard tube filled with [[black powder]], but to make an efficient, accurate rocket or missile involves overcoming a number of difficult problems. The main difficulties include cooling the combustion chamber, pumping the fuel (in the case of a liquid fuel), and controlling and correcting the direction of motion.<ref>{{Citation |author= Richard B. Dow |title=Fundamentals of Advanced Missiles |year=1958 |location=Washington (DC) |publisher=John Wiley & Sons |id=loc 58-13458}}</ref>

===Components===
Rockets consist of a [[rocket propellant|propellant]], a place to put propellant (such as a [[propellant tank]]), and a [[rocket engine nozzle|nozzle]]. They may also have one or more [[rocket engine]]s, [[Spacecraft attitude control|directional stabilization device(s)]] (such as [[fins]], [[vernier engine]]s or engine [[gimbal]]s for [[thrust vectoring]], [[gyroscope]]s) and a structure (typically [[monocoque]]) to hold these components together. Rockets intended for high speed atmospheric use also have an [[aerodynamic]] fairing such as a [[nose cone]], which usually holds the payload.<ref>{{Citation |author=United States Congress. House Select Committee on Astronautics and Space Exploration |title=Space handbook: Astronautics and its applications : Staff report of the Select Committee on Astronautics and Space Exploration |url=http://www.hq.nasa.gov/office/pao/History/conghand/spcover.htm |chapter=4. Rocket Vehicles |chapter-url=http://www.hq.nasa.gov/office/pao/History/conghand/vehicles.htm |series=House document / 86th Congress, 1st session, no. 86 |year=1959 |location=Washington (DC) |publisher=U.S. G.P.O. |oclc=52368435 |url-status=dead |archive-url=https://web.archive.org/web/20090618163819/http://www.hq.nasa.gov/office/pao/History/conghand/spcover.htm |archive-date=2009-06-18 |access-date=2009-07-20 }}</ref>

As well as these components, rockets can have any number of other components, such as wings ([[rocketplane]]s), [[parachute]]s, wheels ([[rocket car]]s), even, in a sense, a person ([[rocket belt]]). Vehicles frequently possess [[Automotive navigation system|navigation systems]] and [[guidance system]]s that typically use [[satellite navigation]] and [[inertial navigation system]]s.

===Engines===
{{Main|Rocket engine}}
[[File:Viking 5C rocketengine.jpg|thumb|upright|[[Viking (rocket engine)|Viking 5C]] rocket engine]]

Rocket engines employ the principle of [[jet engine|jet propulsion]].<ref name="RPE7"/> The rocket engines powering rockets come in a great variety of different types; a comprehensive list can be found in the main article, [[Rocket engine]]. Most current rockets are chemically powered rockets (usually [[internal combustion engines]],<ref>{{cite web |author=Charles Lafayette Proctor II |url=http://concise.britannica.com/ebc/article-9368065/internal-combustion-engine |title=internal combustion engines |publisher=Concise Britannica |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20080114004538/http://concise.britannica.com/ebc/article-9368065/internal-combustion-engine |archive-date=2008-01-14 }}</ref> but some employ a decomposing [[monopropellant]]) that emit a hot [[exhaust gas]]. A rocket engine can use gas propellants, [[Solid-fuel rocket|solid propellant]], [[liquid-propellant rocket|liquid propellant]], or a [[hybrid rocket|hybrid mixture of both solid and liquid]]. Some rockets use heat or pressure that is supplied from a source other than the [[chemical reaction]] of propellant(s), such as [[steam rocket]]s, [[solar thermal rocket]]s, [[nuclear thermal rocket]] engines or simple pressurized rockets such as [[water rocket]] or [[cold gas thruster]]s. With combustive propellants a chemical reaction is initiated between the [[fuel]] and the [[oxidizer]] in the [[combustion]] chamber, and the resultant hot gases accelerate out of a [[rocket engine nozzle]] (or [[nozzle]]s) at the rearward-facing end of the rocket. The [[acceleration]] of these gases through the engine exerts force ("thrust") on the combustion chamber and nozzle, propelling the vehicle (according to [[Newton's Third Law]]). This actually happens because the force (pressure times area) on the combustion chamber wall is unbalanced by the nozzle opening; this is not the case in any other direction. The shape of the nozzle also generates force by directing the exhaust gas along the axis of the rocket.<ref name="RPE7"/>

===Propellant===
{{Main|Rocket propellant}}
[[File:Gas Core light bulb.png|thumb|left|Gas Core light bulb]]

Rocket propellant is mass that is stored, usually in some form of [[propellant]] tank or casing, prior to being used as the propulsive mass that is ejected from a [[rocket engine]] in the form of a [[fluid]] [[jet (fluid)|jet]] to produce [[thrust]].<ref name="RPE7"/> For chemical rockets often the propellants are a fuel such as [[liquid hydrogen]] or [[kerosene]] burned with an oxidizer such as [[liquid oxygen]] or [[nitric acid]] to produce large volumes of very hot gas. The oxidiser is either kept separate and mixed in the combustion chamber, or comes premixed, as with solid rockets.

Sometimes the propellant is not burned but still undergoes a chemical reaction, and can be a 'monopropellant' such as [[hydrazine]], [[nitrous oxide]] or [[hydrogen peroxide]] that can be [[catalyst|catalytically]] decomposed to hot gas.

Alternatively, an inert propellant can be used that can be externally heated, such as in [[steam rocket]], [[solar thermal rocket]] or [[nuclear thermal rocket]]s.<ref name="RPE7"/>

For smaller, low performance rockets such as [[attitude control thruster]]s where high performance is less necessary, a pressurised fluid is used as propellant that simply escapes the spacecraft through a propelling nozzle.<ref name="RPE7"/>

=== Pendulum rocket fallacy ===
[[File:Pendulum rocket fallacy.png|thumb|Illustration of the pendulum rocket fallacy. Whether the motor is mounted at the bottom (left) or top (right) of the vehicle, the thrust vector (T) points along an axis that is fixed to the vehicle (top), rather than pointing vertically (bottom) independent of vehicle attitude, which would lead the vehicle to rotate.]]

The first [[liquid-fuel rocket]], constructed by [[Robert H. Goddard]], differed significantly from modern rockets. The [[rocket engine]] was at the top and the fuel tank at the bottom of the rocket,<ref>{{cite book |url=http://dln.nasa.gov/media/storage/DNY9-12activities.pdf |publisher=NASA |title=Discover NASA and You |archive-url=https://web.archive.org/web/20100527221503/http://dln.nasa.gov/media/storage/DNY9-12activities.pdf |archive-date=2010-05-27 |url-status=dead }}</ref> based on Goddard's belief that the rocket would achieve stability by "hanging" from the engine like a [[pendulum]] in flight.<ref>{{cite AV media |people=[[Scott Manley]] |title=The Pendulum Rocket Fallacy |medium=[[YouTube]] |url=https://www.youtube.com/watch?v=Tx4cjP-GRAY | archive-url=https://ghostarchive.org/varchive/youtube/20211030/Tx4cjP-GRAY| archive-date=2021-10-30|access-date=2020-10-02}}{{cbignore}}</ref> However, the rocket veered off course and crashed {{convert|184|ft}} away from the [[launch pad|launch site]],<ref>{{cite book|last=Streissguth|first=Thomas|title=Rocket man: the story of Robert Goddard|publisher=Twenty-First Century Books|year=1995|pages=[https://archive.org/details/rocketmanstoryof00stre/page/37 37]|isbn=0-87614-863-1|url-access=registration|url=https://archive.org/details/rocketmanstoryof00stre/page/37}}</ref> indicating that the rocket was no more stable than one with the rocket engine at the base.<ref name="Sutton">{{cite book|last=Sutton|first=George P.|title=History of Liquid Propellant Rocket Engines|year=2006|publisher=American Institute of Aeronautics and Astronautics|location=Reston, Virginia|pages=267, 269}}</ref>

==Uses==
Rockets or other similar [[reaction engine|reaction devices]] carrying their own propellant must be used when there is no other substance (land, water, or air) or force ([[gravity]], [[magnetism]], [[light]]) that a [[vehicle]] may usefully employ for propulsion, such as in space. In these circumstances, it is necessary to carry all the [[propellant]] to be used.

However, they are also useful in other situations:

===Military===
{{main|Rocket artillery|Missile}}
[[File:Trident II missile image.jpg|upright|thumb|A [[Trident (missile)|Trident II missile]] launched from sea]]

Some military weapons use rockets to propel [[warhead]]s to their targets. A rocket and its payload together are generally referred to as a ''[[missile]]'' when the weapon has a [[guidance system]] (not all missiles use rocket engines, some use other engines such as [[jet engine|jets]]) or as a ''[[rocket (weapon)|rocket]]'' if it is unguided. Anti-tank and [[Surface-to-air missile|anti-aircraft missiles]] use rocket engines to engage targets at high speed at a range of several miles, while [[intercontinental ballistic missiles]] can be used to deliver multiple [[nuclear warheads]] from thousands of miles, and [[anti-ballistic missile]]s try to stop them. Rockets have also been tested for [[reconnaissance]], such as the [[Ping-Pong (rocket)|Ping-Pong rocket]], which was launched to surveil enemy targets, however, recon rockets have never come into wide use in the military.

===Science and research===
{{See also|Space probe}}
[[File:Bumper.jpg|thumb|upright|A [[Bumper (rocket)|Bumper]] sounding rocket]]
[[Sounding rocket]]s are commonly used to carry instruments that take readings from {{convert|50|km|mi|sp=us}} to {{convert|1500|km|mi|sp=us}} above the surface of the Earth.<ref>{{cite web |first1=Elaine|last1=Marconi |title=What is a Sounding Rocket?|url=http://www.nasa.gov/missions/research/f_sounding.html|publisher=NASA|access-date=28 May 2016|url-status=live|archive-url=https://web.archive.org/web/20160602020154/http://www.nasa.gov/missions/research/f_sounding.html|archive-date=2 June 2016}}</ref>
The [[first images of Earth from space]] were obtained from a [[V-2]] rocket in 1946 ([[V-2 No. 13|flight #13]]).<ref name="APL">{{cite journal|last=Fraser|first=Lorence|year=1985|title=High Altitude Research at the Applied Physics Laboratory in the 1940s|journal=Johns Hopkins APL Technical Digest|volume=6|issue=1|pages=92–99|url=https://www.jhuapl.edu/Content/techdigest/pdf/V06-N01/06-01-Fraser.pdf|access-date=18 October 2016}}</ref>

Rocket engines are also used to propel [[rocket sled]]s along a rail at extremely high speed. The world record for this is Mach 8.5.<ref>{{cite web |title=Test sets world land speed record |url=http://www.af.mil/news/story.asp?storyID=123004755 |publisher=www.af.mil |access-date=2008-03-18 |url-status=dead |archive-url=https://web.archive.org/web/20130601084727/http://www.af.mil/news/story.asp?storyID=123004755 |archive-date=June 1, 2013 }}</ref>

===Spaceflight===
{{Main|Spaceflight}}

Larger rockets are normally launched from a [[launch pad]] that provides stable support until a few seconds after ignition. Due to their high exhaust velocity—{{convert|2500|to|4500|m/s|km/h mph|abbr=on}}—rockets are particularly useful when very high speeds are required, such as orbital speed at approximately {{convert|7800|m/s|km/h mph|abbr=on}}. Spacecraft delivered into orbital trajectories become [[artificial satellites]], which are used for many commercial purposes. Indeed, rockets remain the only way to launch [[spacecraft]] into orbit and beyond.<ref>{{cite web |url=http://spaceflightnow.com/tracking/index.html |title=Spaceflight Now – worldwide launch schedule |publisher=Spaceflightnow.com |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20130911172414/http://spaceflightnow.com/tracking/index.html |archive-date=2013-09-11 }}</ref> They are also used to rapidly accelerate spacecraft when they change orbits or de-orbit for [[landing]]. Also, a rocket may be used to soften a hard parachute landing immediately before touchdown (see [[retrorocket]]).

===Rescue===
[[File:Apollo Pad Abort Test -2.jpg|thumb|left|upright|Apollo LES [[pad abort test]] with [[Boilerplate (spaceflight)|boilerplate]] crew module]]
Rockets were used to propel a line to a stricken ship so that a [[Breeches buoy]] can be used to [[rescue]] those on board. Rockets are also used to launch [[flare|emergency flare]]s.

Some crewed rockets, notably the [[Saturn V]]<ref>{{cite web |url=http://www.apollosaturn.com/asnr/escape.htm |title=Apollo launch escape subsystem |publisher=ApolloSaturn |access-date=2012-12-10 |url-status=live |archive-url=https://web.archive.org/web/20120716192337/http://www.apollosaturn.com/asnr/escape.htm |archive-date=2012-07-16 }}</ref> and [[Soyuz (rocket)|Soyuz]],<ref name=soyuzt>{{cite web |url=http://www.astronautix.com/flights/soyzt101.htm |title=Soyuz T-10-1 'Launch vehicle blew up on pad at Tyuratam; crew saved by abort system' |publisher=Astronautix.com |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20140805134401/http://astronautix.com/flights/soyzt101.htm |archive-date=2014-08-05 }}</ref> have [[launch escape system]]s. This is a small, usually solid rocket that is capable of pulling the crewed capsule away from the main vehicle towards safety at a moments notice. These types of systems have been operated several times, both in testing and in flight, and operated correctly each time.

This was the case when the [[Launch escape system|Safety Assurance System]] (Soviet nomenclature) successfully pulled away the L3 capsule during three of the four failed launches of the Soviet Moon rocket, [[N1 (rocket)|N1]] vehicles [[N1 (rocket)#Launch history|3L, 5L and 7L]]. In all three cases the capsule, albeit uncrewed, was saved from destruction. Only the three aforementioned N1 rockets had functional Safety Assurance Systems. The outstanding vehicle, [[N1 (rocket)#Launch history|6L]], had dummy upper stages and therefore no escape system giving the N1 booster a 100% success rate for egress from a failed launch.<ref>{{cite web |last1=Wade|first1=Mark|title=N1 Manned Lunar Launch Vehicle|url=http://www.astronautix.com/lvs/n1.htm|website=astronautix.com|publisher=Encyclopedia Astronautica|access-date=24 June 2014|url-status=dead|archive-url=https://web.archive.org/web/20120221044312/http://www.astronautix.com/lvs/n1.htm|archive-date=21 February 2012}}</ref><ref>{{cite web |last1=Wade |first1=Mark |title=N1 5L launch – 1969.07.03 |url=http://www.astronautix.com/details/n15h5170.htm |website=astronautix.com |publisher=Encyclopedia Astronautica |access-date=24 June 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150727072221/http://www.astronautix.com/details/n15h5170.htm |archive-date=27 July 2015 }}</ref><ref>{{cite book|last1=Harvey|first1=Brian|title=Soviet and Russian lunar exploration|date=2007|publisher=Springer|location=Berlin|isbn=978-0-387-73976-2|page=226|url=https://books.google.com/books?id=nVeY7vMCtOkC&pg=PA226}}</ref><ref>{{cite web |title=N1 (vehicle 5L) moon rocket Test – launch abort system activated|url=https://www.youtube.com/watch?v=AyoBHBOnscY&noredirect=1|website=YouTube|publisher=2015 YouTube, LLC|access-date=12 January 2015|url-status=live|archive-url=https://web.archive.org/web/20150517160815/https://www.youtube.com/watch?v=AyoBHBOnscY&noredirect=1|archive-date=17 May 2015}}</ref>

A successful escape of a crewed capsule occurred when [[Soyuz 7K-ST No. 16L|Soyuz T-10]], on a mission to the [[Salyut 7]] [[space station]], exploded on the pad.<ref>{{cite web |last1=Wade|first1=Mark|title=Soyuz T-10-1|url=http://www.astronautix.com/flights/soyzt101.htm|website=astronautix.com|publisher=Encyclopedia Astronautica|access-date=24 June 2014|url-status=dead|archive-url=https://web.archive.org/web/20140805134401/http://astronautix.com/flights/soyzt101.htm|archive-date=5 August 2014}}</ref>

Solid rocket propelled [[ejection seat]]s are used in many military aircraft to propel crew away to safety from a vehicle when flight control is lost.<ref>{{cite web |last=Bonsor |first=Kevin |url=http://science.howstuffworks.com/ejection-seat1.htm |title=Howstuff works ejection seats |publisher=Science.howstuffworks.com |date=2001-06-27 |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20100406173354/http://science.howstuffworks.com/ejection-seat1.htm |archive-date=2010-04-06 }}</ref>
{{clear}}

===Hobby, sport, and entertainment===
{{main|Model rocket}}
A model rocket is a small rocket designed to reach low altitudes (e.g., {{convert|100|–|500|m|ft|abbr=on}} for {{convert|30|g|oz|abbr=on}} model) and [[Model rocket#Model rocket recovery methods|be recovered]] by a variety of means.

According to the United States [[National Association of Rocketry]] (nar) Safety Code,<ref name="autogenerated1">{{cite web |url=http://nar.org/NARmrsc.html |publisher=[[National Association of Rocketry]] |title=Model Rocket Safety Code |access-date=2019-10-30 |archive-url=https://web.archive.org/web/20140205202319/http://www.nar.org/NARmrsc.html |archive-date=2014-02-05 |url-status=dead }}</ref> model rockets are constructed of paper, wood, plastic and other lightweight materials. The code also provides guidelines for motor use, launch site selection, launch methods, launcher placement, recovery system design and deployment and more. Since the early 1960s, a copy of the Model Rocket Safety Code has been provided with most model rocket kits and motors. Despite its inherent association with extremely flammable substances and objects with a pointed tip traveling at high speeds, model rocketry historically has proven<ref>{{cite web |url=http://www.nar.org/safety.html |title=Safety |publisher=National Association of Rocketry |access-date=2012-07-06 |archive-url=https://web.archive.org/web/20140207062024/http://www.nar.org/safety.html |archive-date=2014-02-07 |url-status=dead }}</ref><ref>{{cite web |url=http://exploration.grc.nasa.gov/education/rocket/rktparts.html |title=Model Rockets |publisher=[[National Aeronautics and Space Administration]] |work=exploration.grc.nasa.gov |access-date=2012-07-06 |archive-url=https://web.archive.org/web/20120410054356/http://exploration.grc.nasa.gov/education/rocket/rktparts.html |archive-date=2012-04-10 |url-status=dead }}</ref> to be a very safe hobby and has been credited as a significant source of inspiration for children who eventually become [[scientist]]s and [[engineer]]s.<ref>{{cite web |url=http://www.nar.org/pdf/Organizational%20Statement%20of%20the%20NAR.pdf |title=Organizational statement of the NAR |publisher=National Association of Rocketry}}</ref>

Hobbyists build and fly a wide variety of model rockets. Many companies produce model rocket kits and parts but due to their inherent simplicity some hobbyists have been known to make rockets out of almost anything. Rockets are also used in some types of consumer and professional [[fireworks]]. A [[water rocket]] is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is usually a used plastic soft drink bottle. The water is forced out by a pressurized gas, typically compressed air. It is an example of Newton's third law of motion.

The scale of amateur rocketry can range from a small rocket launched in one's own backyard to a rocket that reached space.<ref>{{cite web |url=http://www.coloradospacenews.com/csxt-go-fast-rocket-confirms-multiple-world-records/|title=CSXT Go Fast! Rocket Confirms Multiple World Records|publisher=Colorado Space News|date=4 September 2014|url-status=dead|archive-url=https://web.archive.org/web/20160304090304/http://www.coloradospacenews.com/csxt-go-fast-rocket-confirms-multiple-world-records/|archive-date=4 March 2016|access-date=28 May 2016}}</ref> Amateur rocketry is split into three categories according to total engine [[Impulse (physics)|impulse]]: low-power, mid-power, and [[High-power rocketry|high-power]].

[[Hydrogen peroxide]] rockets are used to power [[jet packs]],<ref>{{cite web|title=Demonstration of the flying rocket belt, Fort Eustis, Virginia and the Pentagon, 06/07/1961|date=June 7, 1961|url=https://www.youtube.com/watch?v=VWwWnFpeoBc
|publisher=U.S. National Archives|access-date=April 30, 2023}}</ref> and have been used to power [[rocket car|cars]] and a rocket car holds the all time (albeit unofficial) [[drag racing]] record.<ref>{{cite web |url=http://www.eurodragster.com/news/news1002.asp?Story=oct30#oct30 |title=Sammy Miller |publisher=Eurodragster.com |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20130602100129/http://www.eurodragster.com/news/news1002.asp?Story=oct30#oct30 |archive-date=2013-06-02 }}</ref>

Corpulent Stump is the most powerful non-commercial rocket ever launched on an Aerotech engine in the United Kingdom.<ref>{{cite news |title='Amateur' rocket launch delayed |url=http://news.bbc.co.uk/1/hi/uk/6963299.stm |access-date=10 October 2023 |work=[[BBC News]] |date=25 August 2007}}</ref><ref>{{cite news |title=Rocket blasts into record books |url=http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/6965328.stm |access-date=10 October 2023 |work=[[BBC News]] |date=27 August 2007}}</ref><ref name="Taylor">{{cite news |last1=Taylor |first1=Marianne |title=Rocket men's quest for command of the Ayr |url=http://www.eveningtimes.co.uk/news/display.var.1645304.0.rocket_mens_quest_for_command_of_the_ayr.php |access-date=10 October 2023 |work=Evening Times |date=27 August 2007 |archive-url=https://web.archive.org/web/20070930153858/http://www.eveningtimes.co.uk/news/display.var.1645304.0.rocket_mens_quest_for_command_of_the_ayr.php |archive-date=30 September 2007}}</ref>

== Flight ==
[[File:STS-134 launch 2.ogv|thumb|Video of the launch of {{OV|105}} on [[STS-134]]]]
Launches for [[orbital spaceflight]]s, or into [[interplanetary space]], are usually from a fixed location on the ground, but would also be possible from an aircraft or ship.

Rocket launch technologies include the entire set of systems needed to successfully launch a vehicle, not just the vehicle itself, but also the [[firing control system]]s, [[mission control center]], [[launch pad]], [[ground station]]s, and [[tracking station]]s needed for a successful launch or recovery or both. These are often collectively referred to as the "[[ground segment]]".

Orbital [[launch vehicle]]s commonly take off vertically, and then begin to progressively lean over, usually following a [[gravity turn]] trajectory.

Once above the majority of the atmosphere, the vehicle then angles the rocket jet, pointing it largely horizontally but somewhat downwards, which permits the vehicle to gain and then maintain altitude while increasing horizontal speed. As the speed grows, the vehicle will become more and more horizontal until at orbital speed, the engine will cut off.

All current vehicles ''stage'', that is, jettison hardware on the way to orbit. Although [[Single-stage-to-orbit|vehicles have been proposed]] which would be able to reach orbit without staging, none have ever been constructed, and, if powered only by rockets,  the [[Tsiolkovsky rocket equation|exponentially increasing fuel requirements]] of such a vehicle would make its useful payload tiny or nonexistent. Most current and historical launch vehicles "expend" their jettisoned hardware, typically by allowing it to crash into the ocean, but some have recovered and reused jettisoned hardware, either by parachute or by propulsive landing.

[[File:PSLV XL C40 Cartosat-2F hazard zones for falling stage debris based on NOTAM.svg|thumb|Doglegged flight path of a PSLV launch to polar inclinations avoiding {{nowrap|Sri Lankan}} landmass]]
When launching a spacecraft to orbit, a "{{visible anchor|dogleg}}" is a guided, powered turn during ascent phase that causes a rocket's flight path to deviate from a "straight" path. A dogleg is necessary if the desired launch azimuth, to reach a desired orbital inclination, would take the [[ground track]] over land (or over a populated area, e.g. Russia usually does launch over land, but over unpopulated areas), or if the rocket is trying to reach an orbital plane that does not reach the [[latitude]] of the launch site. Doglegs are undesirable due to extra onboard fuel required, causing heavier load, and a reduction of vehicle performance.<ref>{{cite web|title=Moonport, CH1-2|url=https://www.hq.nasa.gov/office/pao/History/SP-4204/ch1-2.html|access-date=2020-07-31|website=www.hq.nasa.gov|archive-date=2020-09-25|archive-url=https://web.archive.org/web/20200925195412/https://www.hq.nasa.gov/office/pao/History/SP-4204/ch1-2.html|url-status=dead}}</ref><ref>{{Cite news|date=2011-06-22|title=Another task for the PSLV|language=en|work=The Hindu|url=https://www.thehindu.com/opinion/editorial/another-task-for-the-pslv/article2123861.ece|access-date=2020-07-31|issn=0971-751X}}</ref>

==Noise==
[[File:Sound suppression water system test at KSC Launch Pad 39A.jpg|thumb|upright=1.0|Workers and media witness the Sound Suppression Water System test at [[Launch Pad 39A]]]]
Rocket exhaust generates a significant amount of acoustic energy. As the [[supersonic]] exhaust collides with the ambient air, [[shock wave]]s are formed. The [[sound intensity]] from these shock waves depends on the size of the rocket as well as the exhaust velocity. The sound intensity of large, high performance rockets could potentially kill at close range.<ref name="CR566-3">{{Citation |last1=Potter |first1=R.C |last2=Crocker |first2=M.J |title=Acoustic Prediction Methods for Rocket Engines, Including the Effects of Clustered Engines and Deflected Exhaust Flow, CR-566 |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660030602_1966030602.pdf |location=Washington, D.C. |publisher=NASA |year=1966 |oclc=37049198 |url-status=live |archive-url=https://web.archive.org/web/20131206122446/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660030602_1966030602.pdf |archive-date=2013-12-06 }}{{Page needed|date=September 2010}}</ref>

The [[Space Shuttle]] generated 180&nbsp;dB of noise around its base.<ref>{{cite web |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020094348.pdf |title=Launch Pad Vibroacoustics Research at NASA/KSC |archive-url=https://web.archive.org/web/20170302233823/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020094348.pdf |archive-date=2017-03-02 |url-status=dead |access-date=30 April 2016}}</ref> To combat this, NASA developed a sound suppression system which can flow water at rates up to 900,000 gallons per minute (57&nbsp;m<sup>3</sup>/s) onto the launch pad. The water reduces the noise level from 180&nbsp;dB down to 142&nbsp;dB (the design requirement is 145&nbsp;dB).<ref>{{cite web |url=http://www.nasa.gov/mission_pages/shuttle/launch/sound-suppression-system.html |title=Sound Suppression System |archive-url=https://web.archive.org/web/20110629143632/http://www.nasa.gov/mission_pages/shuttle/launch/sound-suppression-system.html |archive-date=2011-06-29 |access-date=30 April 2016}}</ref> Without the sound suppression system, acoustic waves would reflect off of the launch pad towards the rocket, vibrating the sensitive payload and crew. These acoustic waves can be so severe as to damage or destroy the rocket.

Noise is generally most intense when a rocket is close to the ground, since the noise from the engines radiates up away from the jet, as well as reflecting off the ground. This noise can be reduced somewhat by flame trenches with roofs, by water injection around the jet and by deflecting the jet at an angle.<ref name="CR566-3"/>

For crewed rockets various methods are used to reduce the sound intensity for the passengers, and typically the placement of the astronauts far away from the rocket engines helps significantly. For the passengers and crew, when a vehicle goes [[supersonic]] the sound cuts off as the sound waves are no longer able to keep up with the vehicle.<ref name="CR566-3"/>

==Physics==

===Operation===
{{Main|Rocket engine}}
[[File:A balloon with a tapering nozzle.png|thumb|upright|A balloon with a tapering nozzle. The balloon is pushed by the higher pressure at the top than found around the inside of the nozzle.]]

The [[Reaction (physics)|effect]] of the combustion of propellant in the rocket engine is to increase the internal energy of the resulting gases, utilizing the stored chemical energy in the fuel.{{citation needed|date=February 2016}} As the internal energy increases, pressure increases, and a nozzle is used to convert this energy into a directed kinetic energy. This produces thrust against the ambient environment to which these gases are released.{{citation needed|date=February 2016}} The ideal direction of motion of the exhaust is in the direction so as to cause thrust. At the top end of the combustion chamber the hot, energetic gas fluid cannot move forward, and so, it pushes upward against the top of the rocket engine's [[combustion chamber]]. As the combustion gases approach the exit of the combustion chamber, they increase in speed. The effect of the [[Rocket engine nozzle|convergent]] part of the rocket engine nozzle on the high pressure fluid of combustion gases, is to cause the gases to accelerate to high speed. The higher the speed of the gases, the lower the pressure of the gas ([[Bernoulli's principle]] or [[conservation of energy]]) acting on that part of the combustion chamber. In a properly designed engine, the flow will reach Mach 1 at the throat of the nozzle. At which point the speed of the flow increases. Beyond the throat of the nozzle, a bell shaped expansion part of the engine allows the gases that are expanding to push against that part of the rocket engine. Thus, the bell part of the nozzle gives additional thrust. Simply expressed, for every action there is an equal and opposite reaction, according to [[Newton's third law]] with the result that the exiting gases produce the reaction of a force on the rocket causing it to accelerate the rocket.<ref>{{cite book|last1=Warren|first1=J. W.|title=Understanding force: an account of some aspects of teaching the idea of force in school, college and university courses in engineering, mathematics and science|date=1979|publisher=Murray|location=London|isbn=978-0-7195-3564-2|pages=[https://archive.org/details/understandingfor0000warr/page/37 37–38]|url=https://archive.org/details/understandingfor0000warr/page/37}}</ref>{{#tag:ref|"If you have ever seen a big fire hose spraying water, you may have noticed that it takes a lot of strength to hold the hose (sometimes you will see two or three firefighters holding the hose). The hose is acting like a rocket engine. The hose is throwing water in one direction, and the firefighters are using their strength and weight to counteract the reaction. If they were to let go of the hose, it would thrash around with tremendous force. If the firefighters were all standing on skateboards, the hose would propel them backward at great speed!"<ref>The confusion is illustrated in {{cite web |url=http://science.howstuffworks.com/rocket.htm |title=How Rocket Engines Work |last=Brain |first=Marshall |work=Howstuffworks.com |date=April 2000 |access-date=22 August 2022}}</ref>|group=nb}}

[[File:Rocket thrust.svg|thumb|right|Rocket thrust is caused by pressures acting on both the combustion chamber and nozzle]]
In a closed chamber, the pressures are equal in each direction and no acceleration occurs. If an opening is provided in the bottom of the chamber then the pressure is no longer acting on the missing section. This opening permits the exhaust to escape. The remaining pressures give a resultant thrust on the side opposite the opening, and these pressures are what push the rocket along.

The shape of the nozzle is important. Consider a balloon propelled by air coming out of a tapering nozzle. In such a case the combination of air pressure and viscous friction is such that the nozzle does not push the balloon but is ''pulled'' by it.<ref>{{cite book|last1=Warren|first1=J. W.|title=Understanding force: an account of some aspects of teaching the idea of force in school, college and university courses in engineering, mathematics and science|date=1979|publisher=Murray|location=London|isbn=978-0-7195-3564-2|page=[https://archive.org/details/understandingfor0000warr/page/28 28]|url=https://archive.org/details/understandingfor0000warr/page/28}}</ref> Using a convergent/divergent nozzle gives more force since the exhaust also presses on it as it expands outwards, roughly doubling the total force. If propellant gas is continuously added to the chamber then these pressures can be maintained for as long as propellant remains. Note that in the case of liquid propellant engines, the pumps moving the propellant into the combustion chamber must maintain a pressure larger than the combustion chamber—typically on the order of 100 atmospheres.<ref name="RPE7"/>

As a side effect, these pressures on the rocket also act on the exhaust in the opposite direction and accelerate this exhaust to very high speeds (according to [[Newton's Third Law]]).<ref name="RPE7"/> From the principle of [[conservation of momentum]] the speed of the exhaust of a rocket determines how much momentum increase is created for a given amount of propellant. This is called the rocket's ''[[specific impulse]]''.<ref name="RPE7"/> Because a rocket, propellant and exhaust in flight, without any external perturbations, may be considered as a closed system, the total momentum is always constant. Therefore, the faster the net speed of the exhaust in one direction, the greater the speed of the rocket can achieve in the opposite direction. This is especially true since the rocket body's mass is typically far lower than the final total exhaust mass.

===Forces on a rocket in flight===
[[File:Rktfor.gif|thumb|upright|Forces on a rocket in flight]]
The general study of the [[force]]s on a rocket is part of the field of [[ballistics]]. Spacecraft are further studied in the subfield of [[astrodynamics]].

Flying rockets are primarily affected by the following:<ref>{{cite web |url=http://www.grc.nasa.gov/WWW/K-12/VirtualAero/BottleRocket/airplane/rktfor.html |title=Four forces on a model rocket |publisher=NASA |date=2000-09-19 |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20121129204215/http://www.grc.nasa.gov/WWW/k-12/VirtualAero/BottleRocket/airplane/rktfor.html |archive-date=2012-11-29 }}</ref>
* [[Thrust]] from the engine(s)
* [[Gravity]] from [[celestial bodies]]
* [[Drag (physics)|Drag]] if moving in atmosphere
* [[Lift (force)|Lift]]; usually relatively small effect except for [[rocket-powered aircraft]]

In addition, the [[centrifugal force (fictitious)|inertia and centrifugal pseudo-force]] can be significant due to the path of the rocket around the center of a celestial body; when high enough speeds in the right direction and altitude are achieved a stable [[orbit]] or [[escape velocity]] is obtained.

These forces, with a stabilizing tail (the ''[[empennage]]'') present will, unless deliberate control efforts are made, naturally cause the vehicle to follow a roughly [[parabola|parabolic]] trajectory termed a [[gravity turn]], and this trajectory is often used at least during the initial part of a launch. (This is true even if the rocket engine is mounted at the nose.) Vehicles can thus maintain low or even zero [[angle of attack]], which minimizes transverse [[stress (physics)|stress]] on the [[launch vehicle]], permitting a weaker, and hence lighter, launch vehicle.<ref name=space-sourcebook>{{cite book|first1=Samuel|last1=Glasstone|title=Sourcebook on the Space Sciences|url=https://books.google.com/books?id=K6k0AAAAMAAJ|publisher=D. Van Nostrand Co.|date= 1965|access-date=28 May 2016|page=209|oclc=232378|url-status=live|archive-url=https://web.archive.org/web/20171119163047/https://books.google.com/books?id=K6k0AAAAMAAJ|archive-date=19 November 2017}}</ref><ref name=thesis>{{Cite thesis|first=David W. |last=Callaway |title=Coplanar Air Launch with Gravity-Turn Launch Trajectories |type=Master's thesis |publisher=Air Force Institute of Technology |date=March 2004 |url=https://scholar.afit.edu/etd/3922/ |page = 2 }}</ref>
{{clear}}

====Drag====
{{main|Drag (physics)|Gravity drag|Aerodynamic drag}}
Drag is a force opposite to the direction of the rocket's motion relative to any air it is moving through. This slows the speed of the vehicle and produces structural loads. The deceleration forces for fast-moving rockets are calculated using the [[drag equation]].

Drag can be minimised by an aerodynamic [[nose cone]] and by using a shape with a high [[ballistic coefficient]] (the "classic" rocket shape—long and thin), and by keeping the rocket's [[angle of attack]] as low as possible.

During a launch, as the vehicle speed increases, and the atmosphere thins, there is a point of maximum aerodynamic drag called [[max Q]]. This determines the minimum aerodynamic strength of the vehicle, as the rocket must avoid [[buckling]] under these forces.<ref name=maxq>{{cite web |url=http://www.aerospaceweb.org/question/aerodynamics/q0025.shtml |title=Space Shuttle Max-Q |publisher=Aerospaceweb |date=2001-05-06 |access-date=2012-12-10}}</ref>

====Net thrust====
{{For|a more detailed model of the net thrust of a rocket engine that includes the effect of atmospheric pressure|Rocket engine#Net thrust}}
[[File:Rocket nozzle expansion.svg|thumb|upright|[[Rocket engine#Nozzle|A rocket jet shape]] varies based on external air pressure. From top to bottom:{{unbulleted list|Underexpanded|Ideally expanded|Overexpanded|Grossly overexpanded}}]]

A typical rocket engine can handle a significant fraction of its own mass in propellant each second, with the propellant leaving the nozzle at several kilometres per second. This means that the [[thrust-to-weight ratio]] of a rocket engine, and often the entire vehicle can be very high, in extreme cases over 100. This compares with other jet propulsion engines that can exceed 5 for some of the better<ref>{{cite web |url=http://www.geae.com/engines/military/j85/index.html |title=General Electric J85 |publisher=Geae.com |date=2012-09-07 |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20110722155949/http://www.geae.com/engines/military/j85/index.html |archive-date=2011-07-22 }}</ref> engines.<ref>{{cite web |url=http://www.thrustssc.com/thrustssc/Club/Secure/Arfons_Last_Stand.html |title=Mach 1 Club |publisher=Thrust SSC |access-date=2016-05-28 |url-status=dead |archive-url=https://web.archive.org/web/20160617103717/http://www.thrustssc.com/thrustssc/Club/Secure/Arfons_Last_Stand.html |archive-date=2016-06-17 }}</ref>

The net thrust of a rocket is

{{block indent|<math>F_n = \dot{m}\;v_{e},</math><ref name="RPE7"/>{{rp|2–14}}}}

where

{{block indent|<math> \dot{m} =\,</math>propellant flow (kg/s or lb/s)}}
{{block indent|<math>v_{e} =\,</math>the [[effective exhaust velocity]] (m/s or ft/s).}}

The effective exhaust velocity <math>v_{e}</math> is more or less the speed the exhaust leaves the vehicle, and in the vacuum of space, the effective exhaust velocity is often equal to the actual average exhaust speed along the thrust axis. However, the effective exhaust velocity allows for various losses, and notably, is reduced when operated within an atmosphere.

The rate of propellant flow through a rocket engine is often deliberately varied over a flight, to provide a way to control the thrust and thus the airspeed of the vehicle. This, for example, allows minimization of aerodynamic losses<ref name=maxq/> and can limit the increase of [[g-force|''g''-forces]] due to the reduction in propellant load.

===Total impulse===
{{Main|Impulse (physics)}}
Impulse is defined as a force acting on an object over time, which in the absence of opposing forces (gravity and aerodynamic drag), changes the [[momentum]] (integral of mass and velocity) of the object. As such, it is the best performance class (payload mass and terminal velocity capability) indicator of a rocket, rather than takeoff thrust, mass, or "power". The total impulse of a rocket (stage) burning its propellant is:<ref name="RPE7"/>{{rp|27}}

{{block indent|<math>I = \int F dt</math>}}

When there is fixed thrust, this is simply:

{{block indent|<math>I = F t\;</math>}}

The total impulse of a multi-stage rocket is the sum of the impulses of the individual stages.
{{Clear}}

===Specific impulse===
{{Main|specific impulse}}
{{Specific impulse|align=right}}
As can be seen from the thrust equation, the effective speed of the exhaust controls the amount of thrust produced from a particular quantity of fuel burnt per second.

An equivalent measure, the net impulse per weight unit of propellant expelled, is called [[Specific impulse|specific Impulse]], <math>I_{sp}</math>, and this is one of the most important figures that describes a rocket's performance. It is defined such that it is related to the effective exhaust velocity by:

{{block indent|<math>v_e = I_{sp} \cdot g_0</math><ref name="RPE7"/>{{rp|29}}}}

where:
{{block indent|<math>I_{sp}</math> has units of seconds}}
{{block indent|<math>g_0</math> is the acceleration at the surface of the Earth}}

Thus, the greater the specific impulse, the greater the net thrust and performance of the engine. <math>I_{sp}</math> is determined by measurement while testing the engine. In practice the effective exhaust velocities of rockets varies but can be extremely high, ~4500&nbsp;m/s, about 15 times the sea level speed of sound in air.

===Delta-v (rocket equation)===
{{Main|Tsiolkovsky rocket equation}}
[[File:Delta-Vs for inner Solar System.svg|thumb|upright|A map of approximate [[Delta-v]]'s around the Solar System between Earth and [[Mars]]<ref>{{cite web |url=http://www.pma.caltech.edu/~chirata/deltav.html |title=table of cislunar/mars delta-vs |archive-url=https://web.archive.org/web/20070701211813/http://www.pma.caltech.edu/~chirata/deltav.html |archive-date=2007-07-01}}</ref><ref>{{cite web |url=http://www.strout.net/info/science/delta-v/intro.html |title=cislunar delta-vs |publisher=Strout.net |access-date=2012-12-10 |url-status=live |archive-url=https://web.archive.org/web/20000312041150/http://www.strout.net/info/science/delta-v/intro.html |archive-date=2000-03-12 }}</ref>]]

The [[delta-v]] capacity of a rocket is the theoretical total change in velocity that a rocket can achieve without any external interference (without air drag or gravity or other forces).

When <math>v_e</math> is constant, the delta-v that a rocket vehicle can provide can be calculated from the [[Tsiolkovsky rocket equation]]:<ref>{{cite web |url=http://www.projectrho.com/rocket/rocket3c.html |title=Choose Your Engine |publisher=Projectrho.com |date=2012-06-01 |access-date=2012-12-10 |url-status=live |archive-url=https://web.archive.org/web/20100529042131/http://www.projectrho.com/rocket/rocket3c.html |archive-date=2010-05-29 }}</ref>

:<math>\Delta v\ = v_e \ln \frac {m_0} {m_1}</math>

where:
{{block indent|<math>m_0</math> is the initial total mass, including propellant, in kg (or lb)}}
{{block indent|<math>m_1</math> is the final total mass in kg (or lb)}}
{{block indent|<math>v_e</math> is the effective exhaust velocity in m/s (or ft/s)}}
{{block indent|<math>\Delta v\ </math> is the delta-v in m/s (or ft/s)}}

When launched from the Earth practical delta-vs for a single rockets carrying payloads can be a few km/s. Some theoretical designs have rockets with delta-vs over 9&nbsp;km/s.

The required delta-v can also be calculated for a particular manoeuvre; for example the delta-v to launch from the surface of the Earth to [[low Earth orbit]] is about 9.7&nbsp;km/s, which leaves the vehicle with a sideways speed of about 7.8&nbsp;km/s at an altitude of around 200&nbsp;km. In this manoeuvre about 1.9&nbsp;km/s is lost in [[air drag]], [[gravity drag]] and [[potential energy|gaining altitude]].

The ratio <math>\frac {m_0} {m_1}</math> is sometimes called the ''mass ratio''.

===Mass ratios===
{{Main|Mass ratio}}
[[File:Tsiolkovsky rocket equation.svg|thumb|The Tsiolkovsky rocket equation gives a relationship between the mass ratio and the final velocity in multiples of the exhaust speed]]

Almost all of a launch vehicle's mass consists of propellant.<ref>{{cite web |url=http://www-istp.gsfc.nasa.gov/stargaze/Srockhis.htm |title=The Evolution of Rockets |publisher=Istp.gsfc.nasa.gov |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20130108191716/http://www-istp.gsfc.nasa.gov/stargaze/Srockhis.htm |archive-date=2013-01-08 }}</ref> Mass ratio is, for any 'burn', the ratio between the rocket's initial mass and its final mass.<ref>{{cite web |url=http://exploration.grc.nasa.gov/education/rocket/rktwtp.html |title=Rocket Mass Ratios |publisher=Exploration.grc.nasa.gov |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20130216063603/http://exploration.grc.nasa.gov/education/rocket/rktwtp.html |archive-date=2013-02-16 }}</ref> Everything else being equal, a high mass ratio is desirable for good performance, since it indicates that the rocket is lightweight and hence performs better, for essentially the same reasons that low weight is desirable in sports cars.

Rockets as a group have the highest [[thrust-to-weight ratio]] of any type of engine; and this helps vehicles achieve high [[mass ratio]]s, which improves the performance of flights. The higher the ratio, the less engine mass is needed to be carried. This permits the carrying of even more propellant, enormously improving the delta-v. Alternatively, some rockets such as for rescue scenarios or racing carry relatively little propellant and payload and thus need only a lightweight structure and instead achieve high accelerations. For example, the Soyuz escape system can produce 20&nbsp;''g''.<ref name=soyuzt/>

Achievable mass ratios are highly dependent on many factors such as propellant type, the design of engine the vehicle uses, structural safety margins and construction techniques.

The highest mass ratios are generally achieved with liquid rockets, and these types are usually used for [[orbital launch vehicle]]s, a situation which calls for a high delta-v. Liquid propellants generally have densities similar to water (with the notable exceptions of [[liquid hydrogen]] and [[Liquid methane rocket fuel|liquid methane]]), and these types are able to use lightweight, low pressure tanks and typically run high-performance [[turbopumps]] to force the propellant into the combustion chamber.

Some notable mass fractions are found in the following table (some aircraft are included for comparison purposes):

{| class="wikitable"
|-
! Vehicle
! Takeoff mass
! Final mass
! [[Mass ratio]]
! [[Propellant mass fraction|Mass fraction]]
|-
| [[Ariane 5]] (vehicle + payload)
| 746,000&nbsp;kg <ref name="ariane">{{cite web| url = http://astronautix.com/lvs/ariane5g.htm| archive-url = https://web.archive.org/web/20031225090030/http://www.astronautix.com/lvs/ariane5g.htm| url-status = dead| archive-date = December 25, 2003| title = Astronautix – Ariane 5g}}</ref> (~1,645,000&nbsp;lb)
| 2,700&nbsp;kg + 16,000&nbsp;kg<ref name="ariane"/> (~6,000&nbsp;lb + ~35,300&nbsp;lb)
| 39.9
| 0.975
|-
| [[Titan 23G]] first stage
| 117,020&nbsp;kg (258,000&nbsp;lb)
| 4,760&nbsp;kg (10,500&nbsp;lb)
| 24.6
| 0.959
|-
| [[Saturn V]]
| 3,038,500&nbsp;kg<ref name="saturnv">{{cite web| url = http://astronautix.com/lvs/saturnv.htm| archive-url = https://web.archive.org/web/20020228155213/http://www.astronautix.com/lvs/saturnv.htm| url-status = dead| archive-date = February 28, 2002| title = Astronautix – Saturn V}}</ref> (~6,700,000&nbsp;lb)
| 13,300&nbsp;kg + 118,000&nbsp;kg<ref name="saturnv"/> (~29,320&nbsp;lb + ~260,150&nbsp;lb)
| 23.1
| 0.957
|-
| [[Space Shuttle]] (vehicle + payload)
| 2,040,000&nbsp;kg (~4,500,000&nbsp;lb)
| 104,000&nbsp;kg + 28,800&nbsp;kg (~230,000&nbsp;lb + ~63,500&nbsp;lb)
| 15.4
| 0.935
|-
| [[Saturn 1B]] (stage only)
| 448,648&nbsp;kg<ref name="saturn">{{cite web| url = http://astronautix.com/lvs/saturnib.htm| archive-url = https://web.archive.org/web/20020305051145/http://www.astronautix.com/lvs/saturnib.htm| url-status = dead| archive-date = March 5, 2002| title = Astronautix – Saturn IB}}</ref> (989,100&nbsp;lb)
| 41,594&nbsp;kg<ref name="saturn"/> (91,700&nbsp;lb)
| 10.7
| 0.907
|-
| [[Virgin Atlantic GlobalFlyer]]
| 10,024.39&nbsp;kg (22,100&nbsp;lb)
| 1,678.3&nbsp;kg (3,700&nbsp;lb)
| 6.0
| 0.83
|-
| [[V-2 rocket|V-2]]
| 13,000&nbsp;kg (~28,660&nbsp;lb) (12.8 ton)
| 
| 3.85
| 0.74 <ref>{{cite web| url = http://www.astronautix.com/lvs/v2.htm| archive-url = https://web.archive.org/web/20020302013547/http://www.astronautix.com/lvs/v2.htm| url-status = dead| archive-date = March 2, 2002| title = Astronautix-V-2}}</ref>
|-
| [[X-15]]
| 15,420&nbsp;kg (34,000&nbsp;lb)
| 6,620&nbsp;kg (14,600&nbsp;lb)
| 2.3
| 0.57<ref name="rlv"/>
|-
| [[Concorde]]
| ~181,000&nbsp;kg (400,000&nbsp;lb <ref name="rlv">{{cite web |url=http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf |title=AIAA2001-4619 RLVs |access-date=2019-02-19 |archive-url=https://web.archive.org/web/20131206012152/http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf |archive-date=2013-12-06 |url-status=dead }}</ref>)
| 
| 2
| 0.5<ref name="rlv"/>
|-
| [[Boeing 747]]
| ~363,000&nbsp;kg (800,000&nbsp;lb<ref name="rlv"/>)
| 
| 2
| 0.5<ref name="rlv"/>
|}

===Staging===
{{Main|Multistage rocket}}
[[File:Artistsconcept separation.jpg|thumb|Spacecraft staging involves dropping off unnecessary parts of the rocket to reduce mass]]
[[File:Ap6-68-HC-191.jpg|thumb|[[Apollo 6]] while dropping the interstage ring]]
Thus far, the required velocity (delta-v) to achieve orbit has been unattained by any single rocket because the [[propellant]], tankage, structure, [[guidance system|guidance]], valves and engines and so on, take a particular minimum percentage of take-off mass that is too great for the propellant it carries to achieve that delta-v carrying reasonable payloads. Since [[Single-stage-to-orbit]] has so far not been achievable, orbital rockets always have more than one stage.

For example, the first stage of the Saturn V, carrying the weight of the upper stages, was able to achieve a [[mass ratio]] of about 10, and achieved a specific impulse of 263 seconds. This gives a delta-v of around 5.9&nbsp;km/s whereas around 9.4&nbsp;km/s delta-v is needed to achieve orbit with all losses allowed for.

This problem is frequently solved by [[staging (rocketry)|staging]]—the rocket sheds excess weight (usually empty tankage and associated engines) during launch. Staging is either ''serial'' where the rockets light after the previous stage has fallen away, or ''parallel'', where rockets are burning together and then detach when they burn out.<ref name="NASAstaging">{{cite web |author=NASA |url=https://spaceflightsystems.grc.nasa.gov/education/rocket/rktstage.html |title=Rocket staging |access-date=2016-05-28 |publisher=NASA |work=Beginner's Guide to Rockets |year=2006 |url-status=dead |archive-url=https://web.archive.org/web/20160602123849/https://spaceflightsystems.grc.nasa.gov/education/rocket/rktstage.html |archive-date=2016-06-02 }}</ref>

The maximum speeds that can be achieved with staging is theoretically limited only by the speed of light. However the payload that can be carried goes down geometrically with each extra stage needed, while the additional delta-v for each stage is simply additive.

===Acceleration and thrust-to-weight ratio===
{{Main|thrust-to-weight ratio}}
From Newton's second law, the acceleration, <math>a</math>, of a vehicle is simply:

{{block indent|<math>a = \frac {F_n} {m}</math>}}
where {{mvar|m}} is the instantaneous mass of the vehicle and <math>F_n</math> is the net force acting on the rocket (mostly thrust, but air drag and other forces can play a part).

As the remaining propellant decreases, rocket vehicles become lighter and their acceleration tends to increase until the propellant is exhausted. This means that much of the speed change occurs towards the end of the burn when the vehicle is much lighter.<ref name="RPE7"/> However, the thrust can be throttled to offset or vary this if needed. Discontinuities in acceleration also occur when stages burn out, often starting at a lower acceleration with each new stage firing.

Peak accelerations can be increased by designing the vehicle with a reduced mass, usually achieved by a reduction in the fuel load and tankage and associated structures, but obviously this reduces range, delta-v and burn time. Still, for some applications that rockets are used for, a high peak acceleration applied for just a short time is highly desirable.

The minimal mass of vehicle consists of a rocket engine with minimal fuel and structure to carry it. In that case the [[thrust-to-weight ratio]]{{#tag:ref|"thrust-to-weight ratio {{math|{{var|F}}/{{var|W}}{{sub|{{var|g}}}}}} is a dimensionless parameter that is identical to the acceleration of the rocket propulsion system (expressed in multiples of {{math|{{var|g}}{{sub|0}}}}) ... in a gravity-free vacuum"<ref name="RPE7"/>{{rp|442}}|group=nb}} of the rocket engine limits the maximum acceleration that can be designed. It turns out that rocket engines generally have truly excellent thrust to weight ratios (137 for the [[NK-33]] engine;<ref>{{cite web |url=http://www.astronautix.com/engines/nk33.htm |title=Astronautix NK-33 entry |publisher=Astronautix.com |date=2006-11-08 |access-date=2012-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20020625124013/http://www.astronautix.com/engines/nk33.htm |archive-date=2002-06-25 }}</ref> some solid rockets are over 1000<ref name="RPE7"/>{{rp|442}}), and nearly all really [[g-force|high-g]] vehicles employ or have employed rockets.

The high accelerations that rockets naturally possess means that rocket vehicles are often capable of [[vertical takeoff]], and in some cases, with suitable guidance and control of the engines, also [[VTVL|vertical landing]]. For these operations to be done it is necessary for a vehicle's engines to provide more than the local [[gravitational acceleration]].

===Energy===

====Energy efficiency====
{{Main|propulsive efficiency}}
[[File:Atlantis taking off on STS-27.jpg|thumb|{{OV|104}} during launch phase]]

The energy density of a typical rocket propellant is often around one-third that of conventional hydrocarbon fuels; the bulk of the mass is (often relatively inexpensive) oxidizer. Nevertheless, at take-off the rocket has a great deal of energy in the fuel and oxidizer stored within the vehicle. It is of course desirable that as much of the energy of the propellant end up as [[kinetic energy|kinetic]] or [[potential energy]] of the body of the rocket as possible.

Energy from the fuel is lost in air drag and [[gravity drag]] and is used for the rocket to gain altitude and speed. However, much of the lost energy ends up in the exhaust.<ref name="RPE7"/>{{rp|37–38}}

In a chemical propulsion device, the engine efficiency is simply the ratio of the kinetic power of the exhaust gases and the power available from the chemical reaction:<ref name="RPE7"/>{{rp|37–38}}

{{block indent|<math>\eta_c= \frac {\frac {1} {2}\dot{m}v_e^2} {\eta_{combustion} P_{chem} }</math>}}

100% efficiency within the engine ([[Heat engine#Efficiency|engine efficiency]] <math>\eta_c = 100\%</math>) would mean that all the heat energy of the combustion products is converted into kinetic energy of the jet. This is not possible, but the near-adiabatic [[rocket engine nozzle|high expansion ratio nozzles]] that can be used with rockets come surprisingly close: when the nozzle expands the gas, the gas is cooled and accelerated, and an energy efficiency of up to 70% can be achieved. Most of the rest is heat energy in the exhaust that is not recovered.<ref name="RPE7"/>{{rp|37–38}} The high efficiency is a consequence of the fact that rocket combustion can be performed at very high temperatures and the gas is finally released at much lower temperatures, and so giving good [[Carnot efficiency]].

However, engine efficiency is not the whole story. In common with the other [[jet engine|jet-based engines]], but particularly in rockets due to their high and typically fixed exhaust speeds, rocket vehicles are extremely inefficient at low speeds irrespective of the engine efficiency. The problem is that at low speeds, the exhaust carries away a huge amount of [[kinetic energy]] rearward. This phenomenon is termed [[propulsive efficiency]] (<math>\eta_p</math>).<ref name="RPE7"/>{{rp|37–38}}

However, as speeds rise, the resultant exhaust speed goes down, and the overall vehicle energetic efficiency rises, reaching a peak of around 100% of the engine efficiency when the vehicle is travelling exactly at the same speed that the exhaust is emitted. In this case the exhaust would ideally stop dead in space behind the moving vehicle, taking away zero energy, and from conservation of energy, all the energy would end up in the vehicle. The efficiency then drops off again at even higher speeds as the exhaust ends up traveling forwards – trailing behind the vehicle.

[[File:Average propulsive efficiency of rockets.png|thumb|Plot of instantaneous propulsive efficiency (blue) and overall efficiency for a rocket accelerating from rest (red) as percentages of the engine efficiency]]From these principles it can be shown that the propulsive efficiency <math>\eta_p</math> for a rocket moving at speed <math>u</math> with an exhaust velocity <math>c</math> is:
{{block indent|<math>\eta_p= \frac {2 \frac {u} {c}} {1 + ( \frac {u} {c} )^2 }</math><ref name="RPE7"/>{{rp|37–38}}}}

And the overall (instantaneous) energy efficiency <math>\eta</math> is:
{{block indent|<math>\eta= \eta_p \eta_c</math>}}

For example, from the equation, with an <math>\eta_c</math> of 0.7, a rocket flying at Mach 0.85 (which most aircraft cruise at) with an exhaust velocity of Mach 10, would have a predicted overall energy efficiency of 5.9%, whereas a conventional, modern, air-breathing jet engine achieves closer to 35% efficiency. Thus a rocket would need about 6x more energy; and allowing for the specific energy of rocket propellant being around one third that of conventional air fuel, roughly 18x more mass of propellant would need to be carried for the same journey. This is why rockets are rarely if ever used for general aviation.

Since the energy ultimately comes from fuel, these considerations mean that rockets are mainly useful when a very high speed is required, such as [[ICBM]]s or [[orbital spaceflight|orbital launch]]. For example, [[NASA]]'s [[Space Shuttle]] fired its engines for around 8.5 minutes, consuming 1,000&nbsp;tonnes of solid propellant (containing 16% aluminium) and an additional 2,000,000&nbsp;litres of liquid propellant (106,261&nbsp;kg of [[liquid hydrogen]] fuel) to lift the 100,000&nbsp;kg vehicle (including the 25,000&nbsp;kg payload) to an altitude of 111&nbsp;km and an orbital [[velocity]] of 30,000&nbsp;km/h. At this altitude and velocity, the vehicle had a kinetic energy of about 3&nbsp;TJ and a potential energy of roughly 200&nbsp;GJ. Given the initial energy of 20&nbsp;TJ,{{#tag:ref|The energy density is 31MJ per kg for aluminum and 143&nbsp;MJ/kg for liquid hydrogen, this means that the vehicle consumed around 5&nbsp;TJ of solid propellant and 15&nbsp;TJ of hydrogen fuel.|group=nb}} the Space Shuttle was about 16% energy efficient at launching the orbiter.

Thus jet engines, with a better match between speed and jet exhaust speed (such as [[turbofans]]—in spite of their worse <math>\eta_c</math>)—dominate for subsonic and supersonic atmospheric use, while rockets work best at hypersonic speeds. On the other hand, rockets serve in many short-range ''relatively'' low speed military applications where their low-speed inefficiency is outweighed by their extremely high thrust and hence high accelerations.

====Oberth effect====
{{Main|Oberth effect}}
One subtle feature of rockets relates to energy. A rocket stage, while carrying a given load, is capable of giving a particular [[delta-v]]. This delta-v means that the speed increases (or decreases) by a particular amount, independent of the initial speed. However, because [[kinetic energy]] is a square law on speed, this means that the faster the rocket is travelling before the burn the more [[orbital energy]] it gains or loses.

This fact is used in interplanetary travel. It means that the amount of delta-v to reach other planets, over and above that to reach escape velocity can be much less if the delta-v is applied when the rocket is travelling at high speeds, close to the Earth or other planetary surface; whereas waiting until the rocket has slowed at altitude multiplies up the effort required to achieve the desired trajectory.

==Safety, reliability and accidents==
{{See also| List of spaceflight-related accidents and incidents}}
{{Expand section|date=May 2016}}
[[File:Challenger explosion.jpg|thumb|{{OV|99}} torn apart T+73 seconds after hot gases escaped the [[Solid rocket booster|SRBs]], causing the breakup of the Shuttle stack]]
The reliability of rockets, as for all physical systems, is dependent on the quality of engineering design and construction.

Because of the enormous chemical energy in [[rocket propellant]]s (greater energy by weight than explosives, but lower than [[gasoline]]), consequences of accidents can be severe. Most space missions have some problems.<ref name="Janes">{{cite web |url=http://www.janes.com/aerospace/civil/news/jsd/jsd030203_3_n.shtml|title=A brief history of space accidents|date=2003-02-03|publisher=Jane's Civil Aerospace|access-date=2010-04-24|archive-url=https://web.archive.org/web/20030204073904/http://www.janes.com/aerospace/civil/news/jsd/jsd030203_3_n.shtml|archive-date=2003-02-04}}</ref> In 1986, following the [[Space Shuttle Challenger disaster|Space Shuttle ''Challenger'' disaster]], American physicist [[Richard Feynman]], having served on the [[Rogers Commission]], estimated that the chance of an unsafe condition for a launch of the Shuttle was very roughly 1%;<ref>{{cite web |url=http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt |title=Rogers commission Appendix F |access-date=2012-12-10 |url-status=live |archive-url=https://web.archive.org/web/20120911052800/http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt |archive-date=2012-09-11 }}</ref> more recently the historical per person-flight risk in orbital spaceflight has been calculated to be around 2%<ref>{{cite web |url=http://www.space.com/missionlaunches/spacetourism_future_040930.html |title=Going Private: The Promise and Danger of Space Travel By Tariq Malik |publisher=Space.com |date=2004-09-30 |access-date=2012-12-10 |url-status=live |archive-url=https://web.archive.org/web/20110107124459/http://www.space.com/missionlaunches/spacetourism_future_040930.html |archive-date=2011-01-07 }}</ref> or 4%.<ref name=SpaceReview>{{cite web |url=http://www.thespacereview.com/article/36/2|title=Weighing the risks of human spaceflight|publisher=[[The Space Review]]|date=21 July 2003|access-date=1 December 2010|url-status=dead|archive-url=https://web.archive.org/web/20101123233332/http://www.thespacereview.com/article/36/2|archive-date=23 November 2010}}</ref>

In May 2003 the astronaut office made clear its position on the need and feasibility of improving crew safety for future NASA crewed missions indicating their "consensus that an order of magnitude reduction in the risk of human life during ascent, compared to the [[Space Shuttle]], is both achievable with current technology and consistent with NASA's focus on steadily improving rocket reliability".<ref>{{Cite book|last1=Fragola|first1=J.|last2=Baum|first2=J.D.|last3=Sauvageau|first3=D.|last4=Horowitz|first4=S.J.|title=RAMS '06. Annual Reliability and Maintainability Symposium, 2006 |chapter=Reliability and crew safety assessment for a solid rocket booster/J-2S launcher |date=January 2006|chapter-url=https://ieeexplore.ieee.org/document/1677430|pages=545–550|doi=10.1109/RAMS.2006.1677430|isbn=1-4244-0007-4|s2cid=22788307}}</ref>

==Costs and economics==
The costs of rockets can be roughly divided into propellant costs, the costs of obtaining and/or producing the 'dry mass' of the rocket, and the costs of any required support equipment and facilities.<ref name=aday>[http://www.fourmilab.ch/documents/rocketaday.html "A Rocket a Day Keeps the High Costs Away"] {{webarchive|url=https://web.archive.org/web/20081103045215/http://www.fourmilab.ch/documents/rocketaday.html |date=2008-11-03 }} by John Walker. September 27, 1993.</ref>

Most of the takeoff mass of a rocket is normally propellant. However propellant is seldom more than a few times more expensive than gasoline per kilogram (as of 2009 gasoline was about {{convert|1|$/kg|abbr=on|disp=sqbr}} or less), and although substantial amounts are needed, for all but the very cheapest rockets, it turns out that the propellant costs are usually comparatively small, although not completely negligible.<ref name=aday/> With liquid oxygen costing {{convert|0.15|$/kg}} and liquid hydrogen {{convert|2.20|$/kg|abbr=on}}, the [[Space Shuttle]] in 2009 had a liquid propellant expense of approximately $1.4 million for each launch that cost $450 million from other expenses (with 40% of the mass of propellants used by it being liquids in the [[external fuel tank]], 60% solids in the [[Space Shuttle Solid Rocket Booster|SRBs]]).<ref>{{cite web |url=http://www-pao.ksc.nasa.gov/kscpao/nasafact/pdf/ssp.pdf |title=Space Shuttle Use of Propellants and Fluids |publisher=NASA |access-date=2011-04-30 |url-status=dead |archive-url=https://web.archive.org/web/20111017180215/http://www-pao.ksc.nasa.gov/kscpao/nasafact/pdf/SSP.pdf |archive-date=October 17, 2011 }}</ref><ref>{{cite web |url=http://www-pao.ksc.nasa.gov/nasafact/count2.htm |title=NASA Launch Vehicles and Facilities |publisher=NASA |access-date=2011-04-30 |url-status=dead |archive-url=https://web.archive.org/web/20110427020520/http://www-pao.ksc.nasa.gov/nasafact/count2.htm |archive-date=2011-04-27 }}</ref><ref>{{cite web |url=http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html |title=Space Shuttle and International Space Station |publisher=NASA |access-date=2011-04-30 |url-status=live |archive-url=https://web.archive.org/web/20110507113329/http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html |archive-date=2011-05-07 }}</ref>

Even though a rocket's non-propellant, dry mass is often only between 5–20% of total mass,<ref>{{cite web |url=http://www.spacetethers.com/massfraction.html |title=Mass Fraction |publisher=Andrews Space and Technology (original figure source) |access-date=2011-04-30 |url-status=dead |archive-url=https://web.archive.org/web/20120425073303/http://www.spacetethers.com/massfraction.html |archive-date=2012-04-25 }}</ref> nevertheless this cost dominates. For hardware with the performance used in orbital [[launch vehicle]]s, expenses of $2000–$10,000+ per kilogram of [[dry weight]] are common, primarily from engineering, fabrication, and testing; raw materials amount to typically around 2% of total expense.<ref>Regis, Ed (1990), ''Great Mambo Chicken And The Transhuman Condition: Science Slightly Over The Edge'', Basic Books, {{ISBN|0-201-56751-2}}. [http://groups.google.com/group/sci.space/browse_thread/thread/dcc29174a504c200/7e68102f0a014325?hl=en&ie=UTF-8&oe=utf-8&q Excerpt online]</ref><ref name = CheapRockets>[[:File:LEOonthecheap.pdf|U.S. Air Force Research Report No. AU-ARI-93-8: LEO On The Cheap]]. Retrieved April 29, 2011.</ref> For most rockets except reusable ones (shuttle engines) the engines need not function more than a few minutes, which simplifies design.

Extreme performance requirements for rockets reaching orbit correlate with high cost, including intensive quality control to ensure reliability despite the limited [[safety factor]]s allowable for weight reasons.<ref name=CheapRockets/> Components produced in small numbers if not individually machined can prevent amortization of R&D and facility costs over mass production to the degree seen in more pedestrian manufacturing.<ref name=CheapRockets/> Amongst liquid-fueled rockets, complexity can be influenced by how much hardware must be lightweight, like pressure-fed engines can have two orders of magnitude lesser part count than pump-fed engines but lead to more weight by needing greater tank pressure, most often used in just small maneuvering thrusters as a consequence.<ref name=CheapRockets/>

To change the preceding factors for orbital launch vehicles, proposed methods have included mass-producing simple rockets in large quantities or on large scale,<ref name=aday/> or developing [[reusable launch system|reusable rockets]] meant to fly very frequently to amortize their up-front expense over many payloads, or reducing rocket performance requirements by constructing a [[non-rocket spacelaunch]] system for part of the velocity to orbit (or all of it but with most methods involving some rocket use).

The costs of support equipment, range costs and launch pads generally scale up with the size of the rocket, but vary less with launch rate, and so may be considered to be approximately a fixed cost.<ref name=aday/>

Rockets in applications other than launch to orbit (such as military rockets and [[JATO|rocket-assisted take off]]), commonly not needing comparable performance and sometimes mass-produced, are often relatively inexpensive.

===2010s emerging private competition===
{{Further|Space launch market competition#2010s: Competition and pricing pressure}}
Since the early 2010s, new [[private spaceflight|private options]] for obtaining spaceflight services emerged, bringing substantial [[market competition|price pressure]] into the existing market.<ref name=bbc20141203>{{cite news |title=Europe to press ahead with Ariane 6 rocket |url=https://www.bbc.com/news/science-environment-30251863 |work=BBC News |access-date=2015-06-25 |first=Jonathan |last=Amos |date=3 December 2014}}</ref><ref name=fp20131209>{{cite news |last=Belfiore |first=Michael |title=The Rocketeer |url=https://foreignpolicy.com/articles/2013/12/02/the_rocketeer_elon_musk |access-date=2013-12-11 |newspaper=Foreign Policy |date=2013-12-09 |archive-date=2013-12-10 |archive-url=https://web.archive.org/web/20131210233009/http://www.foreignpolicy.com/articles/2013/12/02/the_rocketeer_elon_musk |url-status=dead }}</ref><ref name=wsj20150917>
{{cite news |last1=Pasztor|first1=Andy |url=https://www.wsj.com/articles/u-s-rocket-supplier-looks-to-break-short-leash-1437339519 |work=[[The Wall Street Journal]] |title=U.S. Rocket Supplier Looks to Break 'Short Leash' |date=2015-09-17 |access-date=2015-10-14 |quote=The aerospace giants [Boeing Co. and Lockheed Martin Corp.] shared almost $500 million in equity profits from the rocket-making venture last year, when it still had a monopoly on the business of blasting the Pentagon's most important satellites into orbit.  But since then, 'They've had us on a very short leash,' Tory Bruno, United Launch's chief executive, said. }}</ref><ref name=wapo20160819>{{cite news |last=Davenport|first=Christian |url=https://www.washingtonpost.com/business/economy/the-billionaire-space-barons-and-the-next-giant-leap/2016/08/19/795a4012-6307-11e6-8b27-bb8ba39497a2_story.html |title=The inside story of how billionaires are racing to take you to outer space |newspaper=[[Washington Post]] |date=2016-08-19 |access-date=2016-08-20 |quote=the government's monopoly on space travel is over}}</ref>

==See also==
{{Portal|Aviation|Rocketry|Spaceflight}}
{{Div col}}
'''Lists'''
* [[Lists of rockets]]
* [[Timeline of rocket and missile technology]]

'''General rocketry'''
* {{annotated link|Aerospace engineering}}
* {{Anl|Battleship (rocketry)}}
* {{annotated link|Rocket garden}}
* {{annotated link|Service structure}}
* {{annotated link|Spaceport}}
* {{annotated link|Variable-mass system}}

'''Rocket propulsion'''
* {{annotated link|Ammonium perchlorate composite propellant}}
* {{annotated link|Pulsed rocket motor}}
* {{annotated link|Steam rocket}}
* {{annotated link|Tripropellant rocket}}
*[[Nuclear thermal rocket]]

'''Recreational rocketry'''
* {{annotated link|High-power rocketry}}
* {{annotated link|National Association of Rocketry}}
* {{annotated link|Tripoli Rocketry Association}}
* {{annotated link|Skyrocket}}

'''Weaponry'''
* {{annotated link|Fire Arrow}}
* {{annotated link|Katyusha rocket launcher}}
* {{annotated link|Rocket-propelled grenade}}
* {{annotated link|Singijeon}}
* {{annotated link|VA-111 Shkval}}

'''Rockets for research'''
* {{annotated link|Rocket sled}}
* {{annotated link|Sounding rocket}}

'''Miscellaneous'''
* {{annotated link|Aircraft}}
* {{annotated link|Equivalence principle}}
* {{annotated link|Launch Pad (card game)}}
* {{annotated link|Rocket Festival}}
* {{annotated link|Rocket mail}}
{{Div col end}}
{{clear right}}

==Notes==
{{Reflist|group=nb}}

{{Reflist|refs=
<ref name=goddard>{{Citation |last = Goddard |first = Robert |title = A Method of Reaching Extreme Altitudes |url= http://www.clarku.edu/research/archives/pdf/ext_altitudes.pdf |year=1919 |oclc=3430998 |author-link=Robert Goddard}}</ref>
}}
<!-- merged into reference section. Commenting out for now until checked everything is ok!
User:WinterSpw wants to know why this wikicomment hasn't been deleted yet.
==References==
{{Refbegin|30em}}
* {{Citation |last1=Allen |first1= H. Julian |last2=Eggers |first2=A. J. |url=http://naca.central.cranfield.ac.uk/reports/1958/naca-report-1381.pdf |title=A Study of the Motion and Aerodynamic Heating of Ballistic Missiles Entering the Earth's Atmosphere at High Supersonic Speeds |publisher= NACA |year=1958 |oclc=86134556}}
* {{Citation |last = Baker |first = A.D. |title = Combat Fleets of the World 2000–2001 |publisher = US Naval Institute Press |location = Annapolis |year = 2000 |isbn = 978-1-55750-197-4 }}
* {{Citation |last=Béon|first=Yves |others=translated from the French '''La planète Dora''' by Béon & Richard L. Fague |title=Planet Dora: A Memoir of the Holocaust and the Birth of the Space Age|year=1997 |publisher=Westview Press, Div. of Harper Collins|isbn=0-8133-3272-9 }}
* {{Citation |last = Buchanan |first = Brenda |title = Gunpowder, Explosives and the State |url= https://books.google.com/books?id=7n6Cg9znFrUC |publisher = Ashgate |location = Aldershot |year = 2006 |isbn = 978-0-7546-5259-5 }}
* {{Citation|first=David W. |last=Callaway |title=Coplanar Air Launch with Gravity-Turn Launch Trajectories |type=Master's thesis |publisher=Air Force Institute of Technology |date=March 2004 |url=https://scholar.afit.edu/etd/3922/ }}
* {{Citation |last = Chase |first = Kenneth |title = Firearms : A global history to 1700 |url=https://books.google.com/books?id=esnWJkYRCJ4C |publisher = Cambridge University Press |location = Cambridge |year = 2003 |isbn = 978-0-521-82274-9 }}
* {{Citation |last = Clary |first = David |title = Rocket Man |publisher = Theia |location = New York |year = 2003 |isbn = 978-0-7868-6817-9 }}
* {{Citation |last = Crosby |first = Alfred W. |title = Throwing Fire: Projectile Technology Through History |year = 2002 |publisher = Cambridge University Press |location = Cambridge |isbn = 0-521-79158-8}}
* {{Citation |last=Esnault-Pelterie |first=Robert |title=Considerations sur les resultats d'un allegement indefini des moteurs |journal=Journal de physique théorique et appliquée |location=Paris |year=1913 |oclc=43942743 |language=fr }}
* {{Citation |author=GAO |title= Cost Benefit Analysis Used in Support of the Space Shuttle Program |url=http://archive.gao.gov/f0302/096542.pdf |location= Washington, DC |publisher= General Accounting Office, US Government |year= 1972 }}
* {{Citation |last = Glasstone |first = Samuel |title = Sourcebook on the Space Sciences |publisher = D. Van Nostrand Company |year = 1965 |oclc=232378}}
* {{Citation |last = Goddard |first = Robert |title = Rockets |publisher = Dover Publications |location = New York |year = 2002 |isbn = 978-0-486-42537-5 }}
* {{Citation |last=Hansen |first=James R. |year=1987 |url=http://history.nasa.gov/SP-4305/sp4305.htm |title=Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917–1958. |work=The NASA History Series, sp-4305 |publisher=NASA |oclc=246830126}}
* {{Citation |last=Harford |first=James |title=Korolev: How One Man Masterminded the Soviet Drive to Beat America to the Moon |year=1997 |publisher=John Wiley & Sons |isbn=0-471-14853-9 }}
* {{Citation|last=Hassan |first=Ahmad Y |url=http://www.history-science-technology.com/Articles/articles%202.htm |title=Gunpowder Composition for Rockets and Cannon in Arabic Military Treatises In Thirteenth and Fourteenth Centuries |access-date=March 29, 2008 |author-link=Ahmad Y Hassan |work=History of Science and Technology in Islam |url-status=dead |archive-url=https://web.archive.org/web/20080226105129/http://www.history-science-technology.com/Articles/articles%202.htm |archive-date=February 26, 2008 }}
* {{Citation|last=Hassan |first=Ahmad Y |url=http://www.history-science-technology.com/Articles/articles%2072.htm |title=Transfer Of Islamic Technology To The West, Part III: Technology Transfer in the Chemical Industries |access-date=2008-03-29 |author-link=Ahmad Y Hassan |work=History of Science and Technology in Islam |url-status=dead |archive-url=https://web.archive.org/web/20080309003120/http://www.history-science-technology.com/Articles/articles%2072.htm |archive-date=March 9, 2008 }}
* {{Citation |last=Houchin |first=Roy |title=U.S. Hypersonic Research and Development: The Rise and Fall of Dyna-Soar, 1944–1963 |year=2006 |publisher=Routledge |location=New York |isbn=0-415-36281-4}}
* {{Citation |last=Hunt |first=Linda |title=Secret Agenda: The United States Government, Nazi Scientists, and Project Paperclip, 1945 to 1990 |year=1991 |publisher=St.Martin's Press |location=New York |isbn=0-312-05510-2}}
* {{Citation|last1=Huzel |first1=D.K. |last2=Huang |first2=D.H. |title=NASA SP-125, Design of Liquid Propellant Rocket Engines |edition=2nd |publisher=NASA |year=1971 |url=https://ntrs.nasa.gov/search.jsp?Ntt=sp-125&Ntk=all&Ntx=mode}}
* {{Citation |last=Johnson |title=Contents and commentary on William Moore's a treatise on the motion of rockets and an essay on naval gunnery |journal=International Journal of Impact Engineering |volume=16 |issue=3 |date = June 1995|oclc=105570427}}
* {{Citation |last = Marconi |first = Elaine M. |date = April 12, 2004 |url = http://www.nasa.gov/missions/research/f_sounding.html |title = What is a Sounding Rocket? |work = Research Aircraft |publisher = NASA |access-date = October 10, 2006}}
* {{Citation |author=NASA |url=https://spaceflightsystems.grc.nasa.gov/education/rocket/rktstage.html |archive-url=https://web.archive.org/web/20160602123849/https://spaceflightsystems.grc.nasa.gov/education/rocket/rktstage.html |url-status=dead |archive-date=2016-06-02 |title=Rocket staging |access-date=2009-06-28 |publisher=NASA |work=Beginner's Guide to Rockets |year=2006}}
* {{Citation |last = Needham |first = Joseph |title = Science and Civilisation in China |url=https://books.google.com/books?id=BZxSnd2Xyb0C |publisher = Cambridge University Press |location = Cambridge |year = 1986 |isbn = 978-0-521-30358-3 }}
* {{Citation |last=Nowak |first=Tadeusz |title=Kazimierz Siemienowicz ok.1600-ok.1951 |year=1969 |publisher=MON Press |location=Warsaw |oclc=254130686 |language=pl}}
* {{Citation |last = Polmar |first = Norman |title = Cold War Submarines |publisher = Brassey's |location = Washington |year = 2004 |isbn = 978-1-57488-594-1 }}
* {{Citation |last1=Potter |first1=R.C |last2=Crocker |title=Acoustic Prediction Methods for Rocket Engines, Including the Effects of Clustered Engines and Deflected Exhaust Flow, CR-566 |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660030602_1966030602.pdf |location=Washington, D.C. |publisher=NASA |year=1966 |oclc=37049198|first2=M.J }}
* {{Citation |author=Space History Division |url=http://www.nasm.si.edu/research/dsh/artifacts/RM-Hale24pdr.htm |archive-url=https://web.archive.org/web/20070818125248/http://www.nasm.si.edu/research/dsh/artifacts/RM-Hale24pdr.htm |archive-date=2007-08-18 |title=Hale 24-Pounder Rocket |publisher=Smithsonian National Air and Space Museum |year=1999}}
* {{Cite DNB|author-link=Henry Morse Stephens|first=Henry Morse|last=Stephens|wstitle=Congreve, William (1772–1828)|volume=12|page=9}}
* {{Citation |last = Sutton |first = George |title = Rocket Propulsion Elements |edition=7th |url=https://books.google.com/books?id=LQbDOxg3XZcC&  |publisher = John Wiley & Sons |location = Chichester |year = 2001 |isbn = 978-0-471-32642-7 }}
* {{Citation |last = Van Riper |first = A Bowdoin |title = Rockets and Missiles |publisher = Greenwood Press |location = Westport |year = 2004 |isbn = 978-0-313-32795-7 }}
* {{Citation |last1=von Braun |first1=Wernher |last2=Ordway |first2=Frederick Ira |title=History of rocketry & space travel |author-link=Wernher Von Braun |year=1966 |publisher=Crowell |location=New York |oclc=566653}}
* {{Citation |last1=von Braun |first1=Wernher |editor= Emme, Eugene Morlock |title=The History of Rocket Technology: The Redstone, Jupiter and Juno |journal=Technology and Culture |volume=IV |issue=4 |date=Autumn 1963 |oclc=39186548 |pages=452–465 |doi=10.2307/3101379}}
* {{Citation |last = Zaloga |first = Steven |title = V-2 ballistic missile 1942–52 |series=New Vanguard |volume=82 |publisher = Oxford University Press |location = Oxford Oxfordshire |year = 2003 |isbn = 978-1-84176-541-9 }}
* {{Citation |url=http://history.msfc.nasa.gov/rocketry/tl1.html |archive-url=https://web.archive.org/web/20000901224401/http://history.msfc.nasa.gov/rocketry/tl1.html |url-status=dead |archive-date=2000-09-01 |title=Rockets in Ancient Times (100 B.C. to 17th Century) |access-date=2009-06-28 |publisher=NASA |work=A Timeline of Rocket History |author=MSFC History Office}}
{{Refend}}
-->

==External links==
{{Commons category|Rockets}}
{{Wiktionary}}
'''Governing agencies'''
* [http://ast.faa.gov/ FAA Office of Commercial Space Transportation]
* [http://www.nasa.gov/ National Aeronautics and Space Administration (NASA)]
* [http://www.nar.org/ National Association of Rocketry (US)]
* [http://www.tripoli.org/ Tripoli Rocketry Association]
* [http://www.acema.com.ar/ Asoc. Coheteria Experimental y Modelista de Argentina] {{Webarchive|url=https://web.archive.org/web/20201027001020/http://acema.com.ar/ |date=2020-10-27 }}
* [http://www.ukra.org.uk/ United Kingdom Rocketry Association]
* [http://www.modellraketen.org/ IMR – German/Austrian/Swiss Rocketry Association]
* [http://www.canadianrocketry.org/ Canadian Association of Rocketry]
* [http://www.isro.gov.in/ Indian Space Research Organisation]

'''Information sites'''
* [[Encyclopedia Astronautica]] – [https://web.archive.org/web/20040514103554/http://www.astronautix.com/lvs/ Rocket and Missile Alphabetical Index]
* [http://www.braeunig.us/space/index.htm Rocket and Space Technology]
* Gunter's Space Page – [http://space.skyrocket.de/ Complete Rocket and Missile Lists]
* [https://web.archive.org/web/20070521025308/http://www.pwrengineering.com/data.htm Rocketdyne Technical Articles]
* [https://web.archive.org/web/20080820201246/http://www.relativitycalculator.com/rocket_equations.shtml Relativity Calculator – Learn Tsiolkovsky's rocket equations]
* [http://sites.google.com/site/rgoddardsite Robert Goddard – America's Space Pioneer] {{Webarchive|url=https://web.archive.org/web/20090205053231/http://sites.google.com/site/rgoddardsite/ |date=2009-02-05 }}

{{Spaceflight}}

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[[Category:Articles containing video clips]]
[[Category:Rockets and missiles| ]]
[[Category:Chinese inventions]]
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[[Category:Rocket-powered aircraft]]
[[Category:Rocketry| ]]
[[Category:Space launch vehicles]]