[{"command":"openDialog","selector":"#drupal-modal","settings":null,"data":"\u003Cdiv id=\u0022republish_modal_form\u0022\u003E\u003Cform class=\u0022modal-form-example-modal-form ecl-form\u0022 data-drupal-selector=\u0022modal-form-example-modal-form\u0022 action=\u0022\/en\/article\/modal\/6406\u0022 method=\u0022post\u0022 id=\u0022modal-form-example-modal-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cp\u003EHorizon articles can be republished for free under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence.\u003C\/p\u003E\n \u003Cp\u003EYou must give appropriate credit. We ask you to do this by:\u003Cbr \/\u003E\n 1) Using the original journalist\u0027s byline\u003Cbr \/\u003E\n 2) Linking back to our original story\u003Cbr \/\u003E\n 3) Using the following text in the footer: This article was originally published in \u003Ca href=\u0027#\u0027\u003EHorizon, the EU Research and Innovation magazine\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003ESee our full republication guidelines \u003Ca href=\u0027\/horizon-magazine\/republish-our-stories\u0027\u003Ehere\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003EHTML for this article, including the attribution and page view counter, is below:\u003C\/p\u003E\u003Cdiv class=\u0022js-form-item form-item js-form-type-textarea form-item-body-content js-form-item-body-content ecl-form-group ecl-form-group--text-area form-no-label ecl-u-mv-m\u0022\u003E\n \n\u003Cdiv\u003E\n \u003Ctextarea data-drupal-selector=\u0022edit-body-content\u0022 aria-describedby=\u0022edit-body-content--description\u0022 id=\u0022edit-body-content\u0022 name=\u0022body_content\u0022 rows=\u00225\u0022 cols=\u002260\u0022 class=\u0022form-textarea ecl-text-area\u0022\u003E\u003Ch2\u003EBrussels to Tokyo in two hours\u003C\/h2\u003E\u003Cp\u003EThat is the sort of possibility offered by hypersonic jets, which travel at many times the speed of sound \u2013 and which researchers in Europe are trying to make a reality.\u003C\/p\u003E\u003Cp\u003E\u2018Getting in a couple of hours to the other side of the world is quite impressive and nearly unimaginable,\u2019 said aerospace engineer Dr Johan Steelant of the European Space Agency in the Netherlands. \u2018I\u2019m still amazed that classical aeroplanes weighing 500 tonnes are able to hang in the air travelling at 800 to 900 kilometres per hour \u2013 but just imagine if we could crank this speed up to seven to eight times faster.\u2019\u003C\/p\u003E\u003Cp\u003EThe speed of sound \u2013\u0026nbsp;1 200 kilometres per hour \u2013\u0026nbsp;has been broken by civilian aeroplanes before, albeit only by two models: the Anglo-French Concorde and the Soviet Union\u2019s Tupolev Tu-144, both of which flew at about twice the speed of sound. Both are now retired.\u003C\/p\u003E\u003Cp\u003EBut even those supersonic aircraft would be left well behind by the prototype being developed by Dr Steelant and colleagues. Known as HEXAFLY, it is expected to travel at seven or eight times the speed of sound.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong style=\u0022font-size: 13.008px; line-height: 1.538em;\u0022\u003EFast target\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ESuch speeds would not easily be reached. One problem will be generating enough thrust to overcome air beating past at over 8 000 kilometres per hour, and even then there are issues of stability and managing the thousand-degree temperatures generated by aerodynamic friction.\u003C\/p\u003E\u003Cp\u003EFortunately Dr Steelant has had prior success: HEXAFLY\u2019s precursor project, LAPCAT-II, saw the researchers test a 1.2-metre physical model in a wind tunnel at 7.4 times the speed of sound. In HEXAFLY, he and his colleagues want to test a 3-metre prototype at similar speeds in the open air.\u003C\/p\u003E\u003Cp\u003EThe basic design of the aircraft is nearly complete, and they are now optimising its mass before the proposed launch in 2018 or 2019. This particular prototype will not generate its own thrust and will be launched from a rocket in order to test flight stability and other factors.\u003C\/p\u003E\u003Cp\u003E\u2018This test will demonstrate that we have mastered the different aspects of the design and the related technologies,\u2019 said Dr Steelant.\u003C\/p\u003E\u003Cp\u003EOne of those related technologies has been developed as part of a project that Dr Steelant also coordinated. Known as ATLLAS-II, it sought to create materials that could withstand the heat generated at hypersonic speeds.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ELightweight\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EThe result of that project was a range of composites called ceramic matrixes. They are similar to the composite materials already used in aircraft, but are treated during manufacture so that the only materials left over are those such as carbon or aluminium oxides which can survive high temperatures, while still being sufficiently light to minimise fuel consumption.\u003Cspan\u003E\u003Cblockquote class=\u0022tw-text-center tw-text-blue tw-font-bold tw-text-2xl lg:tw-w-1\/2 tw-border-2 tw-border-blue tw-p-12 tw-my-8 lg:tw-m-12 lg:tw--ml-16 tw-float-left\u0022\u003E\n \u003Cspan class=\u0022tw-text-5xl tw-rotate-180\u0022\u003E\u201c\u003C\/span\u003E\n \u003Cp class=\u0022tw-font-serif tw-italic\u0022\u003E\u2018Just imagine if we could crank speeds up to seven to eight times faster.\u2019\u003C\/p\u003E\n \u003Cfooter\u003E\n \u003Ccite class=\u0022tw-not-italic tw-font-normal tw-text-sm tw-text-black\u0022\u003EDr Johan Steelant, European Space Agency\u003C\/cite\u003E\n \u003C\/footer\u003E\n\u003C\/blockquote\u003E\n\u003C\/span\u003E\u003C\/p\u003E\u003Cp\u003EFuel itself is a consideration for hypersonic flight, as the kerosene used by conventional airliners is not only heavy but a potent source of greenhouse gas emissions. Liquid hydrogen, liquid methane and even liquid oxygen are prime alternatives, but have to be stored at cryogenic temperatures of -200 to -250 \u003Cspan\u003Edegrees Celsius\u003C\/span\u003E.\u003C\/p\u003E\u003Cp\u003EDr Martin Sippel, an aerospace engineer at the German Aerospace Centre (DLR) in Cologne, coordinated a project called CHATT to investigate fuel management on hypersonic aircraft. The project is now finished, but the researchers believe they got some way towards identifying the best approach.\u003C\/p\u003E\u003Cp\u003EOne of the problems with cryogenic fuels is that they take up a large volume, yet tend to slosh around in large tanks which affects the stability of the plane. For this reason Dr Sippel and colleagues have performed a lot of computer modelling to work out how to reduce sloshing.\u003C\/p\u003E\u003Cp\u003EThe researchers have also built several different demonstrator tanks to see which was best able to withstand cryogenic temperatures. A particularly promising one was made from a carbon-fibre thin-ply material, which, unlike other carbon-fibre designs, did not need a protective internal liner to prevent the propellants seeping through or reacting with the tank\u2019s walls.\u003C\/p\u003E\u003Cp\u003E\u003Cfigure role=\u0022group\u0022 class=\u0022@aligncenter@\u0022\u003E\n\u003Cimg alt=\u0022Hypersonic planes could look significantly different from the aircraft we know today.\u0022 height=\u0022620\u0022 src=\u0022\/research-and-innovation\/sites\/default\/files\/hm\/HypersonicFlight-1-72dpi_0.jpg\u0022 title=\u0022Hypersonic planes could look significantly different from the aircraft we know today.\u0022 width=\u0022585\u0022\u003E\n\u003Cfigcaption class=\u0022tw-italic tw-mb-4\u0022\u003EHypersonic planes could look significantly different from the aircraft we know today.\u003C\/figcaption\u003E\n\u003C\/figure\u003E\n\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EChallenges ahead\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EHowever, Dr Sippel says there is a still a lot left to do. \u2018(We will only know that) all problems are solved when a hypersonic vehicle is in safe and reliable routine operation,\u2019 he said.\u003C\/p\u003E\u003Cp\u003EThe next step is to develop a cryogenic tank demonstrating thermal protection and \u2018health monitoring\u2019 \u2013\u0026nbsp;that is, monitoring of the technical system\u2019s condition over many cycles of filling and depletion.\u003C\/p\u003E\u003Cp\u003EThat would be yet another step towards civilians travelling at eight times the speed of sound. Dr Steelant believes commercial flights could become economically viable towards the middle of the century.\u003C\/p\u003E\u003Cp\u003EBut eight times the speed of sound may just be the start. Some of the concepts investigated in CHATT would be suitable for planes such as DLR\u2019s SpaceLiner, a rocket-propelled craft that is designed to travel at 20 times the speed of sound, making Brussels to Japan in about an hour.\u003C\/p\u003E\u003Cp\u003E\u2018I think it\u0027s about the dream of creating something new and making a difference to today\u2019s conventional subsonic airliners,\u2019 said Dr Sippel.\u003C\/p\u003E\u003C\/textarea\u003E\n\u003C\/div\u003E\n\n \u003Cdiv id=\u0022edit-body-content--description\u0022 class=\u0022ecl-help-block description\u0022\u003E\n Please copy the above code and embed it onto your website to republish.\n \u003C\/div\u003E\n \u003C\/div\u003E\n\u003Cinput autocomplete=\u0022off\u0022 data-drupal-selector=\u0022form-jltljr6ty4fph8srqf5jz7qidtrwwugzat4gu4ygyco\u0022 type=\u0022hidden\u0022 name=\u0022form_build_id\u0022 value=\u0022form-jltljR6tY4FPh8SRqf5jZ7qiDtRWWUgZaT4gU4yGYCo\u0022 \/\u003E\n\u003Cinput data-drupal-selector=\u0022edit-modal-form-example-modal-form\u0022 type=\u0022hidden\u0022 name=\u0022form_id\u0022 value=\u0022modal_form_example_modal_form\u0022 \/\u003E\n\u003C\/form\u003E\n\u003C\/div\u003E","dialogOptions":{"width":"800","modal":true,"title":"Republish this content"}}]