IAC2020: emdrive by Shawyer

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    • IAC2020: emdrive by Shawyer

      LAtests presentation by Roger Shawyer on Emdrive

      The paper

      and the video

      Roger Shawyer wrote:

      Designing an EmDrive thruster for a cubesat presents a number of challenges. Foremost is the need to reduce thesize of the microwave cavity, to enable integration into the cubesat structure. This requirement can be addressed byselection of frequency and operating mode.

      EmDrive propulsion systems have been designed to operate from 900MHz to around 8 GHz. However, to maintainthe low cost cubesat philosophy, a frequency where both components and test equipment are widely available ispreferred. The first choice would seem to be the ISM band (2.4GHz to 2.5 GHz). However this leads to cavity sizeswhich are too big for the largest 12U cubesat structure. The original SPR Flight Thruster was designed around aflight qualified,3.85 GHz TWTA, and as equipment in the new 5G mobile band (3.4GHz to 3.8GHz) is now readilyavailable, this frequency was also chosen for the cubesat design.

      The Flight Thruster had a maximum internal cavity diameter of 200mm, and operated in a TE013 mode. To reducethe maximum diameter to 150mm, the operating mode was changed to TE113. This paper describes the detailedcavity design process, including a description of the design software and the equations used. The resulting cavitydimensions for the cubesat thruster are given, together with E and H field diagrams and plots of wavelength andwave impedance. The placement of input loop, tuner, detector probe and vent are discussed.

      The low power available on a typical Cubesat means that the thruster design must utilise the power in the mostefficient manner. Essentially this requires that the cavity Q must be maximised. This requirement is addressed intwo ways. Firstly the cavity is cooled by using a deployable sunshade, and two deployable cooling panels. Secondly,the end plate alignment, which is critical for high Q and high thrust, is kept within tolerance, by use of the SPRFlight Thruster cavity geometry. A specific thrust of 0.5N/kWm is given for the thruster.

      Thrust measurement is described, and the need for a pre-load during thruster start up, using three techniques, arediscussed.

      The resulting 12U cubesat is described, and tentative missions are proposed, giving a flight time from Low EarthOrbit to a Mars orbit of 8 months, or a time to a Pluto flyby of 4.3 years. Both flight times are within the typicalcubesat operational life of 5 years.

      It seems it talks of Thrust Measurement, but does not report measurements.
      Beside that it seems to propose designe based theory based forecasts.
      If someone can extract the core of the paper... :D
      “Only puny secrets need keeping. The biggest secrets are kept by public incredulity.” (Marshall McLuhan)
      See my raw tech-watch on scoop.it/u/alain-coetmeur & twitter.com/alain_co