Editing Scramjet (section)

==History==

===Before 2000===
The [[Bell X-1]] attained [[Supersonic speed#Supersonic flight|supersonic flight]] in 1947 and, by the early 1960s, rapid progress toward faster aircraft suggested that operational aircraft would be flying at "hypersonic" speeds within a few years. Except for specialized rocket research vehicles like the [[North American X-15]] and other rocket-powered [[spacecraft]], aircraft top speeds have remained level, generally in the range of Mach{{nbsp}}1 to Mach{{nbsp}}3.

During the US aerospaceplane program, between the 1950s and the mid 1960s, [[Alexander Kartveli]] and [[Antonio Ferri]] were proponents of the scramjet approach.

In the 1950s and 1960s, a variety of experimental scramjet engines were built and ground tested in the US and the UK. Antonio Ferri successfully demonstrated a scramjet producing net thrust in November 1964, eventually producing 517 pounds-force (2.30&nbsp;kN), about 80% of his goal. In 1958, an analytical paper discussed the merits and disadvantages of supersonic combustion ramjets.<ref name="weber">{{cite journal|last1=Weber|first1=Richard J.|last2=Mackay|first2=John S.|title=An Analysis of Ramjet Engines Using Supersonic Combustion|url=https://ntrs.nasa.gov/search.jsp?R=19930085282&hterms=weber+mackay&qs=N%3D0%26Ntk%3DAll%26Ntt%3Dweber%2520mackay%26Ntx%3Dmode%2520matchallpartial%26Nm%3D123%7CCollection%7CNASA%2520STI%7C%7C17%7CCollection%7CNACA|website=ntrs.nasa.gov|date=September 1958|publisher=NASA Scientific and Technical Information|access-date=3 May 2016}}</ref> In 1964, [[Frederick S. Billig]] and Gordon L. Dugger submitted a patent application for a supersonic combustion ramjet based on Billig's PhD thesis. This patent was issued in 1981 following the removal of an order of secrecy.<ref name="UMD">{{cite web |url=http://www.eng.umd.edu/ihof/inductees/billig.html |title=Frederick S. Billig, Ph.D. |work=The Clark School Innovation Hall of Fame |publisher=[[University of Maryland]] |archive-url=https://web.archive.org/web/20100609221913/http://www.eng.umd.edu/ihof/inductees/billig.html |archive-date=9 June 2010 |access-date=30 April 2010 }}</ref>

In 1981, tests were made in Australia under the guidance of Professor Ray Stalker in the T3 ground test facility at ANU.<ref name="aus">{{cite news |url=https://www.uq.edu.au/news/article/2002/07/milestones-history-of-scramjets |title=Milestones in the history of scramjets |work=UQ News |publisher=[[University of Queensland]] |date=27 July 2002 |url-status=live |archive-url=https://web.archive.org/web/20160211221907/https://www.uq.edu.au/news/article/2002/07/milestones-history-of-scramjets |archive-date=11 February 2016 |access-date=11 February 2016 }}</ref>

The first successful flight test of a scramjet was performed as a joint effort with [[NASA]], over the Soviet Union in 1991. It was an axisymmetric hydrogen-fueled dual-mode scramjet developed by [[Central Institute of Aviation Motors]] (CIAM), Moscow in the late 1970s, but modernized with a FeCrAl alloy on a converted SM-6 missile to achieve initial flight parameters of Mach 6.8, before the scramjet flew at Mach 5.5. The scramjet flight was flown captive-carry atop the [[S-200 (missile)|SA-5]] [[surface-to-air missile]] that included an experimental flight support unit known as the "Hypersonic Flying Laboratory" (HFL), "Kholod".<ref>{{cite book |last1=Roudakov |first1=Alexander S. |last2=Schickhmann |first2=Y. |last3=Semenov |first3=Vyacheslav L. |last4=Novelli |first4=Ph. |last5=Fourt |first5=O. |title=44th Congress of the International Astronautical Federation |chapter=Flight Testing an Axisymmetric Scramjet – Recent Russian Advances |volume=10 |location=Graz, Austria |publisher=International Astronautical Federation |year=1993 }}</ref>

Then, from 1992 to 1998, an additional six flight tests of the axisymmetric high-speed scramjet-demonstrator were conducted by CIAM together with France and then with [[NASA]].<ref name="AIAA 96-4572">{{cite web |url=http://www.nasa.gov/centers/dryden/pdf/88431main_H-2115.pdf |title=Future Flight Test Plans of an Axisymmetric Hydrogen-Fueled Scramjet Engine on the Hypersonic Flying Laboratory |last1=Roudakov |first1=Alexander S. |last2=Semenov |first2=Vyacheslav L. |last3=Kopchenov |first3=Valeriy I. |last4=Hicks |first4=John W. |work=7th International Spaceplanes and Hypersonics Systems & Technology Conference November 18–22, 1996/Norfolk, Virginia |publisher=[[AIAA]] |date=1996 |url-status=live |archive-url=https://web.archive.org/web/20160212141135/http://www.nasa.gov/centers/dryden/pdf/88431main_H-2115.pdf |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref><ref name="NASA/TP-1998-206548">{{cite web |url=http://www.nasa.gov/centers/dryden/pdf/88580main_H-2243.pdf |title=Recent Flight Test Results of the Joint CIAMNASA Mach 6.5 Scramjet Flight Program |last1=Roudakov |first1=Alexander S. |last2=Semenov |first2=Vyacheslav L. |last3=Hicks |first3=John W. |work=Central Institute of Aviation Motors, Moscow, Russia/NASA Dryden Flight Research Center Edwards, California, USA |publisher=[[NASA]] Center for AeroSpace Information (CASI) |date=1998 |url-status=live |archive-url=https://web.archive.org/web/20160212144411/http://www.nasa.gov/centers/dryden/pdf/88580main_H-2243.pdf |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref> Maximum flight speed greater than Mach{{nbsp}}6.4 was achieved and scramjet operation during 77 seconds was demonstrated. These flight test series also provided insight into autonomous hypersonic flight controls.

===2000s===
{{Main|Scramjet programs}}
[[File:X43a2 nasa scramjet.jpg|thumb|Artist's conception of the [[NASA X-43]] with scramjet attached to the underside|alt=Artist's conception of black, wingless jet with pointed nose profile and two vertical stabilizers traveling high in the atmosphere.]]

In the 2000s, significant progress was made in the development of hypersonic technology, particularly in the field of scramjet engines.

The [[HyShot]] project demonstrated scramjet combustion on 30 July 2002. The scramjet engine worked effectively and demonstrated supersonic combustion in action. However, the engine was not designed to provide thrust to propel a craft. It was designed more or less as a technology demonstrator.<ref name="AIAA-44-10-2366">{{cite journal |title=Flight Data Analysis of the HyShot 2 Scramjet Flight Experiment |journal=AIAA Journal |year=2006 |last1=Smart |first1=Michael K. |last2=Hass |first2=Neal E. |last3=Paull |first3=Allan |volume=44 |issue=10 |pages=2366–2375 |issn=0001-1452 |doi=10.2514/1.20661|bibcode=2006AIAAJ..44.2366S }}</ref>

A joint British and Australian team from UK defense company [[Qinetiq]] and the [[University of Queensland]] were the first group to demonstrate a scramjet working in an atmospheric test.<ref name="1001 inventions">{{cite book |last1=Challoner |first1=Jack |title=1001 Inventions That Changed the World |location=London |publisher=[[Cassell Illustrated]] |date=2 February 2009 |page=932 |isbn=978-1-84403-611-0 }}</ref>

[[Hyper-X]] claimed the first flight of a thrust-producing scramjet-powered vehicle with full aerodynamic maneuvering surfaces in 2004 with the [[NASA X-43|X-43A]].<ref name="AIAA 2005-3334">{{cite book|title=AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference|last1=Harsha|first1=Philip T.|last2=Keel|first2=Lowell C.|last3=Castrogiovanni|first3=Anthony|last4=Sherrill|first4=Robert T.|date=17 May 2005|publisher=[[AIAA]]|isbn=978-1-62410-068-0|location=[[Capua]], Italy|chapter=2005-3334: X-43A Vehicle Design and Manufacture|doi=10.2514/6.2005-3334}}</ref><ref name="X-43 McClinton">{{cite web |url=https://info.aiaa.org/tac/pc/HYTAPC/Shared%20Documents/Meeting%20Presentations/2006%20ASM/AIAA_DL_McClinton.pdf |title=X-43: Scramjet Power Breaks the Hypersonic Barrier |last=McClinton |first=Charles |publisher=[[AIAA]] |date=9 January 2006 |url-status=live |archive-url=https://web.archive.org/web/20160212152951/https://info.aiaa.org/tac/pc/HYTAPC/Shared%20Documents/Meeting%20Presentations/2006%20ASM/AIAA_DL_McClinton.pdf |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref> The last of the three X-43A scramjet tests achieved Mach{{nbsp}}9.6 for a brief time.<ref>{{Cite web|url=https://www.nasa.gov/news-release/nasas-x-43a-scramjet-breaks-speed-record/|title=NASA – NASA's X-43A Scramjet Breaks Speed Record|website=www.nasa.gov|language=en|access-date=13 June 2019}}</ref>

On 15 June 2007, the US Defense Advanced Research Project Agency ([[DARPA]]), in cooperation with the Australian Defence Science and Technology Organisation (DSTO)<!--Please note that "Defence" and "Defense" are different for the US and Australian organizaions/organisations respectively -->, announced a successful scramjet flight at Mach{{nbsp}}10 using rocket engines to boost the test vehicle to hypersonic speeds.<ref name="NewSc 15-06-2007">{{cite news |url=https://www.newscientist.com/article/dn12075-scramjet-hits-mach-10-over-australia-/ |title=Scramjet hits Mach{{nbsp}}10 over Australia |work=[[New Scientist]] |publisher=[[Reed Business Information]] |date=15 June 2007 |url-status=live |archive-url=https://web.archive.org/web/20160212154205/https://www.newscientist.com/article/dn12075-scramjet-hits-mach-10-over-australia-/ |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref><ref>{{Citation |last=Ballard |first=Terry |title=Google Maps and Google Earth |date=2012 |url=http://dx.doi.org/10.1016/b978-1-84334-677-7.50009-7 |work=Google This! |pages=113–124 |access-date=2023-06-02 |publisher=Elsevier|doi=10.1016/b978-1-84334-677-7.50009-7 |isbn=9781843346777 |url-access=subscription }}</ref>

A series of scramjet ground tests was completed at [[NASA]] [[Langley Research Center|Langley]] Arc-Heated Scramjet Test Facility (AHSTF) at simulated [[Mach number|Mach]]{{nbsp}}8 flight conditions. These experiments were used to support HIFiRE flight 2.<ref name="NTRS">{{cite conference |last1=Cabell |first1=Karen |last2=Hass |first2=Neal |last3=Storch |first3=Andrea |last4=Gruber |first4=Mark |date=11 April 2011 |title=HIFiRE Direct-Connect Rig (HDCR) Phase I Scramjet Test Results from the NASA Langley Arc-Heated Scramjet Test Facility |conference=17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference |website=NASA Technical Reports Server |hdl=2060/20110011173 |hdl-access=free}}</ref>

On 22 May 2009, Woomera hosted the first successful test flight of a hypersonic aircraft in HIFiRE (Hypersonic International Flight Research Experimentation). The launch was one of ten planned test flights. The series of flights is part of a joint research program between the Defence Science and Technology Organisation and the US Air Force, designated as the HIFiRE.<ref name="dailytelegraph.com.au">{{cite news |last=Dunning |first=Craig |url=http://www.dailytelegraph.com.au/woomera-hosts-first-hifire-hypersonic-test-flight/story-e6frewsr-1225715365056 |title=Woomera hosts first HIFiRE hypersonic test flight |work=[[The Daily Telegraph (Sydney)|The Daily Telegraph]] |publisher=[[News Corp Australia]] |date=24 May 2009 |access-date=12 February 2016 |archive-date=August 28, 2014|archive-url=https://archive.today/20140828195858/http://www.dailytelegraph.com.au/woomera-hosts-first-hifire-hypersonic-test-flight/story-e6frewsr-1225715365056}}</ref> HIFiRE is investigating hypersonics technology and its application to advanced scramjet-powered space launch vehicles; the objective is to support the new [[Boeing X-51]] scramjet demonstrator while also building a strong base of flight test data for quick-reaction space launch development and hypersonic "quick-strike" weapons.<ref name="dailytelegraph.com.au"/>

===2010s===
On 22 and 23 March 2010, Australian and American defense scientists successfully tested a (HIFiRE) hypersonic rocket. It reached an atmospheric speed of "more than 5,000 kilometres per hour" (Mach{{nbsp}}4) after taking off from the [[Woomera Test Range]] in outback South Australia.<ref name="SMH 2010-03-22">{{cite news |last=AAP |author-link=Australian Associated Press |url=http://www.smh.com.au//breaking-news-national/scientists-conduct-second-hifire-test-20100322-qqrp.html |title=Scientists conduct second HIFiRE test |work=[[The Sydney Morning Herald]] |publisher=[[Fairfax Media]] |date=22 March 2010 |url-status=live |archive-url=https://web.archive.org/web/20160212160428/http://www.smh.com.au//breaking-news-national/scientists-conduct-second-hifire-test-20100322-qqrp.html |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref><ref name="AuBC 2010-03-23">{{cite news |url=http://www.abc.net.au/news/2010-03-23/success-for-hypersonic-outback-flight/375654 |title=Success for hypersonic outback flight |work=ABC News |publisher=[[Australian Broadcasting Corporation|ABC]] |date=23 March 2010 |url-status=live |archive-url=https://web.archive.org/web/20160212161059/http://www.abc.net.au/news/2010-03-23/success-for-hypersonic-outback-flight/375654 |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref>

On 27 May 2010, [[NASA]] and the [[United States Air Force]] successfully flew the [[Boeing X-51|X-51A Waverider]] for approximately 200 seconds at Mach{{nbsp}}5, setting a new world record for flight duration at hypersonic airspeed.<ref>{{cite web|title=Longest Flight at Hypersonic Speed|url=http://www.guinnessworldrecords.com/world-records/longest-flight-at-hypersonic-speed|website=Guinness World Records|archive-url=https://web.archive.org/web/20170706212226/http://www.guinnessworldrecords.com/world-records/longest-flight-at-hypersonic-speed|archive-date=6 July 2017 |access-date=6 July 2017  }}</ref> The Waverider flew autonomously before losing acceleration for an unknown reason and destroying itself as planned. The test was declared a success. The X-51A was carried aboard a [[B-52]], accelerated to Mach{{nbsp}}4.5 via a solid rocket booster, and then ignited the [[Pratt & Whitney]] Rocketdyne scramjet engine to reach Mach{{nbsp}}5 at {{convert|70000|ft|m}}.<ref name="CNET 2010-05-26">{{cite news |last=Skillings |first=Jon |url=http://www.cnet.com/news/x-51a-races-to-hypersonic-record/ |title=X-51A races to hypersonic record |work=[[CNET]] |publisher=[[CBS Interactive]] |date=26 May 2010 |url-status=live |archive-url=https://web.archive.org/web/20160212161352/http://www.cnet.com/news/x-51a-races-to-hypersonic-record/ |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref> However, a second flight on 13 June 2011 was ended prematurely when the engine lit briefly on ethylene but failed to transition to its primary [[JP-7]] fuel, failing to reach full power.<ref name="Space.com 2011-07-29">{{cite news |url=http://www.space.com/12441-hypersonic-x51a-waverider-scramjet-failure.html |title=Hypersonic X-51A Scramjet Failure Perplexes Air Force |work=[[Space.com]] |publisher=[[Purch]] |date=27 July 2011 |url-status=live |archive-url=https://web.archive.org/web/20160212161955/http://www.space.com/12441-hypersonic-x51a-waverider-scramjet-failure.html |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref>

On 16 November 2010, Australian scientists from the [[Australian Defence Force Academy#Academic education|University of New South Wales at the Australian Defence Force Academy]] successfully demonstrated that the high-speed flow in a naturally non-burning scramjet engine can be ignited using a pulsed laser source.<ref name="AuBC 2010-11-16">{{cite news |last=Cooper |first=Dani |url=http://www.abc.net.au/science/articles/2010/11/16/3067887.htm |title=Researchers put spark into scramjets |work=ABC Science |publisher=[[Australian Broadcasting Corporation|ABC]] |date=16 November 2010 |access-date=12 February 2016 }}</ref>

A further [[Boeing X-51|X-51A Waverider]] test failed on 15 August 2012. The attempt to fly the scramjet for a prolonged period at Mach{{nbsp}}6 was cut short when, only 15 seconds into the flight, the X-51A craft lost control and broke apart, falling into the Pacific Ocean north-west of Los Angeles. The cause of the failure was blamed on a faulty control fin.<ref name="BBC 2012-08-15">{{cite news |url=https://www.bbc.com/news/technology-19277620 |title=Hypersonic jet Waverider fails Mach 6 test |work=[[BBC News]] |publisher=[[BBC]] |date=15 August 2012 |url-status=live |archive-url=https://web.archive.org/web/20160212163058/http://www.bbc.com/news/technology-19277620 |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref>

In May 2013, an X-51A Waverider reached 4828&nbsp;km/h (Mach{{nbsp}}3.9) during a three-minute flight under scramjet power. The WaveRider was dropped at {{convert|50000|ft|m}} from a B-52 bomber, and then accelerated to Mach{{nbsp}}4.8 by a solid rocket booster which then separated before the WaveRider's scramjet engine came into effect.<ref name="2013-05-smh">{{cite news |last=AP |author-link=Associated Press |url=http://www.smh.com.au/technology/sci-tech/experimental-hypersonic-aircraft-hits-4828-kmh-20130506-2j2e6.html |title=Experimental hypersonic aircraft hits 4828 km/h |work=[[The Sydney Morning Herald]] |publisher=[[Fairfax Media]] |date=6 May 2013 |url-status=live |archive-url=https://web.archive.org/web/20160212163341/http://www.smh.com.au/technology/sci-tech/experimental-hypersonic-aircraft-hits-4828-kmh-20130506-2j2e6.html |archive-date=12 February 2016 |access-date=12 February 2016 }}</ref>

On 28 August 2016, the Indian space agency [[Indian Space Research Organisation|ISRO]] conducted a successful test of a scramjet engine on a two-stage, solid-fueled rocket. Twin scramjet engines were mounted on the back of the second stage of a two-stage, solid-fueled [[sounding rocket]] called [[Advanced Technology Vehicle]] (ATV), which is ISRO's advanced sounding rocket. The twin scramjet engines were ignited during the second stage of the rocket when the ATV achieved a speed of 7350&nbsp;km/h (Mach{{nbsp}}6) at an altitude of 20&nbsp;km. The scramjet engines were fired for a duration of about 5 seconds.<ref name="Firstpost 2016">{{cite web | title=Scramjet engines successfully tested: All you need to know about Isro's latest feat | website=Firstpost | date=28 August 2016 | url=http://www.firstpost.com/india/scramjet-engines-successfully-tested-all-you-need-to-know-about-isros-latest-feat-2979992.html | access-date=28 August 2016}}</ref><ref>{{cite web|url=http://www.isro.gov.in/update/28-aug-2016/successful-flight-testing-of-isros-scramjet-engine-technology-demonstrator|title=Successful Flight Testing of ISRO's Scramjet Engine Technology Demonstrator – ISRO|website=www.isro.gov.in|archive-date=December 1, 2017|archive-url=https://web.archive.org/web/20171201182039/http://www.isro.gov.in/update/28-aug-2016/successful-flight-testing-of-isros-scramjet-engine-technology-demonstrator}}</ref>

On 12 June 2019, India successfully conducted the maiden flight test of its indigenously developed uncrewed scramjet demonstration aircraft for hypersonic speed flight from a base from [[Abdul Kalam Island]] in the [[Bay of Bengal]] at about 11:25&nbsp;am. The aircraft is called the [[Hypersonic Technology Demonstrator Vehicle]]. The trial was carried out by the [[Defence Research and Development Organisation]]. The aircraft forms an important component of the country's programme for development of a hypersonic [[cruise missile]] system.<ref>{{Cite journal|date=12 June 2019|title=India successfully conducts flight test of unmanned scramjet demonstration aircraft|url=https://timesofindia.indiatimes.com/india/india-successfully-conducts-flight-test-of-unmanned-scramjet-demonstration-aircraft/articleshow/69753799.cms?from=mdr|journal=The Times of India}}</ref><ref>{{Cite journal|date=12 June 2019|title=India test fires Hypersonic Technology Demonstrator Vehicle|url=https://www.business-standard.com/article/news-ians/india-test-fires-hypersonic-technology-demonstrator-vehicle-119061200454_1.html|journal=Business Standard}}</ref>

===2020s===
[[File:Scramjet engine for Hypersonic Cruise Missile.jpg|thumb|DRDO scramjet combustor ground testing for 1,000 seconds. |218x218px]]On 27 September 2021, DARPA announced successful flight of its [[Hypersonic Air-breathing Weapon Concept]] scramjet [[cruise missile]].<ref name="DARPA 2021-09-27">{{cite news |url=https://www.darpa.mil/news-events/2021-09-27 |title= DARPA'S Hypersonic Air-breathing Weapon Concept (HAWC) Achieves Successful Flight |work=[[DARPA]] press release |publisher=[[DARPA]] |date=27 September 2021 }}</ref> Another successful test was carried out in mid-March 2022 amid the [[2022 Russian invasion of Ukraine|Russian invasion of Ukraine]]. Details were kept secret to avoid escalating tension with [[Russia]], only to be revealed by an unnamed [[The Pentagon|Pentagon]] official in early April.<ref>{{Cite web|url=https://www.cnn.com/2022/04/04/politics/us-hypersonic-missile-test/index.html|title = US tested hypersonic missile in mid-March but kept it quiet to avoid escalating tensions with Russia|website = [[CNN]]| date=5 April 2022 }}</ref><ref>{{Cite web | title=Second Successful Flight for DARPA Hypersonic Air-breathing Weapon Concept (HAWC) | url=https://www.darpa.mil/news-events/2022-04-05 | access-date=2025-01-11 | website=www.darpa.mil}}</ref> On 25 April 2025, [[DRDO]] successfully completed over 1,000 seconds of ground testing of a subscale active-cooled scramjet combustor.<ref>{{Cite web |last=Negi |first=Manjeet |date=2025-04-25 |title=India tests scramjet engine for over 1,000 seconds in hypersonic technology leap |url=https://www.indiatoday.in/india/story/india-tests-scramjet-engine-for-over-1000-seconds-hypersonic-technology-leap-drdo-2715275-2025-04-25 |access-date=2025-04-26 |website=India Today |language=en}}</ref>