Zeno Swijtink
09-24-2008, 10:14 PM
<div id="article"><div id="article_body"><h1 id="articlehed">Chinese Say They're Building 'Impossible' Space Drive (https://blog.wired.com/defense/2008/09/chinese-buildin.html)</h1> <div class="date_time"> <p><span style="margin-right:20px;"><span id="contributor" class="c cs">By David Hambling</span></span></p> <p><span style="margin-right:20px;">September 24, 2008</span></p> </div></div></div> <div id="article_text"><p align="left">
https://blog.wired.com/defense/images/2008/09/24/emdrive_2.jpg
Chinese researchers claim they've confirmed the theory behind an "impossible" space drive, and are proceeding to build a demonstration version. If they're right, this might transform the economics of satellites, open up new possibilities for space exploration ñ- and give the Chinese a decisive military advantage in space. <br /> <br /> To say that the "<a href="https://www.emdrive.com/">Emdrive</a>" (short for "electromagnetic drive") concept is controversial would be an understatement. According to Roger Shawyer, the British scientist who developed the concept, the drive converts electrical energy into thrust via microwaves, <a href="https://emdrive.com/faq.html">without violating any laws of physics</a>. Many researchers believe otherwise. An article about the <a href="https://technology.newscientist.com/article/mg19125681.400">Emdrive in <em>New Scientist</em></a> magazine drew a massive volley of criticism. Scientists not only argued that Shawyer's work was blatantly impossible, and that his reasoning was flawed. They also said the <a href="https://www.newscientist.com/blog/fromthepublisher/2006/10/emdrive-on-trial.html">article should never have been published</a>. </p><p>"It is well known that Roger Shawyer's 'electromagnetic relativity drive' violates the law of conservation of momentum, making it simply the latest in a long line of 'perpetuum mobiles' that have been proposed and disproved for centuries," wrote John Costella, an Australian physicist. "<a href="https://www.assassinationscience.com/johncostella/shawyerfraud.pdf">His analysis is rubbish and his 'drive' impossible</a>."</p><p>Shawyer stands by <a href="https://emdrive.com/theory.html">his theoretical work</a>. His company, Satellite Propulsion Research (SPR), has constructed demonstration engines, which he says produce thrust using a tapering resonant cavity filled with microwaves. He is adamant that this is not a perpetual motion machine, and does not violate the law of conservation of momentum because different reference frames apply to the drive and the waves within it. Shawyer's big challenge, he says, has been getting people who will actually look into his claims rather than simply dismissing them. </p></div> <p>Such extravagant claims are usually associatedwith self-taught, backyard inventors claiming Einstein got it all wrong.But Shawyer is a scientist who has worked with radar andcommunication systems and was a program manager at European spacecompany <a href="https://www.astrium.eads.net/">EADS Astrium</a>; his work rests entirely on Einstein being right. The thrust is the result of a <a href="https://emdrive.com/theory.html">relativistic effect</a>and would not occur under simple Newtonian physics. Many have dismissedhis work out of hand, and British government funding has ceased. He hashad some interest from both the United States and China. Now the Chineseconnection with the Northwestern Polytechnical University (NPU) inXi'an seems to have paid off. </p><p>"NPU started their researchprogram in June 2007, under the supervision of Professor Yang Juan.They have independently developed a mathematical simulation which showsunequivocally that a net force can be produced from a simple resonanttapered cavity," Shawyer tells Danger Room. "The thrust levels predicted by thissimulation are similar to those resulting from the SPR design software,and the SPR test results."</p><p>What's more, Shawyer says, NPU is "currently manufacturing" a "thruster" based on this theoretical work. </p><p>"Icould confirm that our mathematical simulation gives the results Dr.Roger Shawyer told you. Now we are submitting our result to a journal.It is now under the consideration of the editor," Professor Yang adds."We also developed a tapered cavity and are preparing an experimentwhich will be completed at the end of this year." </p><p>Needless tosay, independent confirmation is a big deal -- though many will want tosee it published in a peer-reviewed journal. Even when it is, I doubt thecontroversy will subside. Prof. Yang has plenty of experience in thistype of area, having previously done work on <a href="https://cat.inist.fr/?aModele=afficheN&cpsidt=15519209">microwave plasma thrusters</a>,which use a resonant cavity to accelerate a plasma jet for propulsion.While the theory behind the Emdrive is very different, the engineeringprinciples of building the hardware are similar. The Chinese should be capable of determining whether the thruster really works orwhether the apparent forces are caused by experimental errors. </p><p>The thrust produced is small, but significant. <a href="https://www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentation?type=powerpoint">Shawyer compares a C-Band Emdrive </a>with the existing <a href="https://www.boeing.com/defense-space/space/bss/factsheets/xips/nstar/ionengine.html">NSTAR ion thruster used by NASA</a>.The Emdrive produces 85 mN of thrust compared to 92 for the NSTAR(that's about one-third of an ounce), but the Emdrive only consumes aquarter of the amount of power and weighs less than 7 kilos,compared to over 30 kilos. The biggest difference is inpropellant: NSTAR uses 10 grams per hour; the Emdrive uses none. Aslong as it has an electricity supply, the Emdrive will keep going. </p><p>Thepossibilities are phenomenal: Instead of going out of service when theyrun out of fuel, satellites would have greatly extended endurance and be able to move around at will. (We wouldn't <a href="https://blog.wired.com/defense/2008/02/operation-rogue.html">have to shoot them down </a>becauseof the risk from toxic fuel either.) Deep space probes couldgo further, faster ñ- and stop when they arrive. Shawyer calculates thata solar-powered Emdrive could take a manned mission to Mars in 41 days.Provided it works, of course.</p><p>What will China do with thetechnology? It may be relevant that professor Yang is not unknown inmilitary circles, having published a paper called "<a href="https://www.uscc.gov/researchpapers/2007/FINAL_REPORT_1-19-2007_REVISED_BY_MPP.pdf">Plasma Attack Against Low-Orbit Spy Satellites</a>." </p><p>Meanwhile,what about the American interest? Shawyer told me that "the flightthruster program is on hold for the present. [O]nce the U.K. governmenthad provided an export license for a U.S. military application, themajor U.S. aerospace company we had been dealing with stopped talkingto us. " </p><p>The company may have decided that the Emdrive could not work. If they're wrong, China has at least a year's head start in a <a href="https://www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentation?type=powerpoint">technology that will dominate space</a> and make previous satellites as obsolete as sailing ships in the age of steam. </p>
https://blog.wired.com/defense/images/2008/09/24/emdrive_2.jpg
Chinese researchers claim they've confirmed the theory behind an "impossible" space drive, and are proceeding to build a demonstration version. If they're right, this might transform the economics of satellites, open up new possibilities for space exploration ñ- and give the Chinese a decisive military advantage in space. <br /> <br /> To say that the "<a href="https://www.emdrive.com/">Emdrive</a>" (short for "electromagnetic drive") concept is controversial would be an understatement. According to Roger Shawyer, the British scientist who developed the concept, the drive converts electrical energy into thrust via microwaves, <a href="https://emdrive.com/faq.html">without violating any laws of physics</a>. Many researchers believe otherwise. An article about the <a href="https://technology.newscientist.com/article/mg19125681.400">Emdrive in <em>New Scientist</em></a> magazine drew a massive volley of criticism. Scientists not only argued that Shawyer's work was blatantly impossible, and that his reasoning was flawed. They also said the <a href="https://www.newscientist.com/blog/fromthepublisher/2006/10/emdrive-on-trial.html">article should never have been published</a>. </p><p>"It is well known that Roger Shawyer's 'electromagnetic relativity drive' violates the law of conservation of momentum, making it simply the latest in a long line of 'perpetuum mobiles' that have been proposed and disproved for centuries," wrote John Costella, an Australian physicist. "<a href="https://www.assassinationscience.com/johncostella/shawyerfraud.pdf">His analysis is rubbish and his 'drive' impossible</a>."</p><p>Shawyer stands by <a href="https://emdrive.com/theory.html">his theoretical work</a>. His company, Satellite Propulsion Research (SPR), has constructed demonstration engines, which he says produce thrust using a tapering resonant cavity filled with microwaves. He is adamant that this is not a perpetual motion machine, and does not violate the law of conservation of momentum because different reference frames apply to the drive and the waves within it. Shawyer's big challenge, he says, has been getting people who will actually look into his claims rather than simply dismissing them. </p></div> <p>Such extravagant claims are usually associatedwith self-taught, backyard inventors claiming Einstein got it all wrong.But Shawyer is a scientist who has worked with radar andcommunication systems and was a program manager at European spacecompany <a href="https://www.astrium.eads.net/">EADS Astrium</a>; his work rests entirely on Einstein being right. The thrust is the result of a <a href="https://emdrive.com/theory.html">relativistic effect</a>and would not occur under simple Newtonian physics. Many have dismissedhis work out of hand, and British government funding has ceased. He hashad some interest from both the United States and China. Now the Chineseconnection with the Northwestern Polytechnical University (NPU) inXi'an seems to have paid off. </p><p>"NPU started their researchprogram in June 2007, under the supervision of Professor Yang Juan.They have independently developed a mathematical simulation which showsunequivocally that a net force can be produced from a simple resonanttapered cavity," Shawyer tells Danger Room. "The thrust levels predicted by thissimulation are similar to those resulting from the SPR design software,and the SPR test results."</p><p>What's more, Shawyer says, NPU is "currently manufacturing" a "thruster" based on this theoretical work. </p><p>"Icould confirm that our mathematical simulation gives the results Dr.Roger Shawyer told you. Now we are submitting our result to a journal.It is now under the consideration of the editor," Professor Yang adds."We also developed a tapered cavity and are preparing an experimentwhich will be completed at the end of this year." </p><p>Needless tosay, independent confirmation is a big deal -- though many will want tosee it published in a peer-reviewed journal. Even when it is, I doubt thecontroversy will subside. Prof. Yang has plenty of experience in thistype of area, having previously done work on <a href="https://cat.inist.fr/?aModele=afficheN&cpsidt=15519209">microwave plasma thrusters</a>,which use a resonant cavity to accelerate a plasma jet for propulsion.While the theory behind the Emdrive is very different, the engineeringprinciples of building the hardware are similar. The Chinese should be capable of determining whether the thruster really works orwhether the apparent forces are caused by experimental errors. </p><p>The thrust produced is small, but significant. <a href="https://www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentation?type=powerpoint">Shawyer compares a C-Band Emdrive </a>with the existing <a href="https://www.boeing.com/defense-space/space/bss/factsheets/xips/nstar/ionengine.html">NSTAR ion thruster used by NASA</a>.The Emdrive produces 85 mN of thrust compared to 92 for the NSTAR(that's about one-third of an ounce), but the Emdrive only consumes aquarter of the amount of power and weighs less than 7 kilos,compared to over 30 kilos. The biggest difference is inpropellant: NSTAR uses 10 grams per hour; the Emdrive uses none. Aslong as it has an electricity supply, the Emdrive will keep going. </p><p>Thepossibilities are phenomenal: Instead of going out of service when theyrun out of fuel, satellites would have greatly extended endurance and be able to move around at will. (We wouldn't <a href="https://blog.wired.com/defense/2008/02/operation-rogue.html">have to shoot them down </a>becauseof the risk from toxic fuel either.) Deep space probes couldgo further, faster ñ- and stop when they arrive. Shawyer calculates thata solar-powered Emdrive could take a manned mission to Mars in 41 days.Provided it works, of course.</p><p>What will China do with thetechnology? It may be relevant that professor Yang is not unknown inmilitary circles, having published a paper called "<a href="https://www.uscc.gov/researchpapers/2007/FINAL_REPORT_1-19-2007_REVISED_BY_MPP.pdf">Plasma Attack Against Low-Orbit Spy Satellites</a>." </p><p>Meanwhile,what about the American interest? Shawyer told me that "the flightthruster program is on hold for the present. [O]nce the U.K. governmenthad provided an export license for a U.S. military application, themajor U.S. aerospace company we had been dealing with stopped talkingto us. " </p><p>The company may have decided that the Emdrive could not work. If they're wrong, China has at least a year's head start in a <a href="https://www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentation?type=powerpoint">technology that will dominate space</a> and make previous satellites as obsolete as sailing ships in the age of steam. </p>