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Julian Santiago Prowald and Miguel Such Taboada ESA-ESTEC, Structures Section, Mechanical Department. ESA UNCLASSIFIED For Official Use

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Julian Santiago Prowald and Miguel Such Taboada ESA-ESTEC, Structures Section, Mechanical Department ESA UNCLASSIFIED For Official Use 1. Introduction Technical disciplines -Spacecraft and mission design
Julian Santiago Prowald and Miguel Such Taboada ESA-ESTEC, Structures Section, Mechanical Department ESA UNCLASSIFIED For Official Use 1. Introduction Technical disciplines -Spacecraft and mission design -Electromagnetism and RF wave propagation -Thermal control in space -Structures and Mechanisms -Materials science and technology -Manufacturing processes ESA Presentation 10/12/2010 Slide 2 1. Introduction Fundamental performances L S Frequency bands in the microwave spectrum 400 MHz 1.5 GHz 1.5 GHz 3.9 GHz -Frequency allocation: ITU Radio Regulations -Link budget -Polar radiation pattern: gain, directivity and sidelobe isolation -Power handling C X K Q V 3.9 GHz 6.2 GHz 6.2 GHz 10.9 GHz 10.9 GHz 36.0 GHz 36.0 GHz 46.0 GHz 46.0 GHz 56.0 GHz ESA Presentation 10/12/2010 Slide 3 1. Introduction Telecom payloads and antennas Rx antenna Ku-band Transponder Tx antenna 14 GHz carrier DEMUX MUX 12 GHz carrier LNA LO (2 GHz) TWTA or SSPA Telecommunications satellite payload example. Reflectors and radiating elements (feed horns) are directly exposed to the space environment and highly sensitive to the launch mechanical loads. Therefore, they are a major topic in mechanical and thermal design. Above 1 GHz the reflector (dish) antenna is the preferred solution in most applications. ESA Presentation 10/12/2010 Slide 4 1. Introduction Tx antenna Gain GT Power PT Fundamentals: link budget Rx antenna Gain GR Power PR P P R T r G T G R P L 2 (db) 4 r Path loss P L 4 A Boresight gain GT,R 2 eff ESA Presentation 10/12/2010 Slide 5 1. Introduction Fundamentals: radiation diagram 3 dbi SLI HPBW Copolar and crosspolar radiation diagram for a 1.2 m parabolic reflector in V-band (courtesy of HPS GmbH and ASD) ESA Presentation 10/12/2010 Slide 6 1. Introduction Reflector antenna configurations Single paraboloid Cassegrain Gregorian Symmetric (on-set) P P H P E Asymmetric (off-set) P P P H E ESA Presentation 10/12/2010 Slide 7 2. Mechanical / thermal design, analysis and testing - Validate materials and processes selection - Provide support to RF design - Provide deployment and pointing capabilities - Maintain performance parameters within tolerance during lifetime - Survive on-ground and launch loads - Survive space environment ESA Presentation 10/12/2010 Slide 8 2. Mechanical and thermal design, analysis and testing Space Environment (orbit dependent) - Vacuum: volatility and contamination - Partial compensation of gravity in orbit: orbital and attitude manoeuvres, gravity gradient - Thermal environment: sun, earth, albedo, eclipse, deep space - UV, radiation and particles - Micrometeoroids and debris impacts - Magnetic field - Electrostatic discharge ESA Presentation 10/12/2010 Slide 9 2. Mechanical and thermal design, analysis and testing Courtesy of Astrium ST ESA Presentation 10/12/2010 Slide 10 2. Mechanical and thermal design, analysis and testing Courtesy of Astrium ST ESA Presentation 10/12/2010 Slide 11 2. Mechanical and thermal design, analysis and testing P1 Gs s A Input solar flux to the front skin Q rad 4 T T A Radiation emitted by the front skin Q rad 4 T T A Radiation emitted by the back skin Q c Cs T 1 T 2 Conductive heat flux from the front to the back skin. G s s 4 4 Cs T T T ) ( 1 T2 A 4 4 Cs T T T ) ( 1 T2 A ESA Presentation 10/12/2010 Slide 12 2. Mechanical and thermal design, analysis and testing PSD (Pa2/Hz) 1000 Ariane 5 Acceptance LEAF 2001 meas ured filtered octave f (Hz) 600 ESA Presentation 10/12/2010 Slide 13 2. Mechanical and thermal design, analysis and testing Chamber Dimensions (m) & Volume (m 3 ) OASPL (db re Po) Reverberation time Sound production LEAF s at 100 Hz 4 modulators & exp. horns. Fluid: N 2 IABG s at 100 Hz 3 modulators & exp. horns. Fluid: air Intespace s 3 modulators & exp. horns. Fluid: N 2 Courtesy of EADS-CASA ESA Presentation 10/12/2010 Slide 14 3. Large Deployable Antennas Courtesy of Thales Alenia and NPO-EGS ESA Presentation 10/12/2010 Slide 15 3. Large Deployable Antennas Wrap-Rib Antenna, JPL & Lockheed Missiles 9.1 m WRA launched in 1974 with the Applications Technology Satellite 6 Sector of the 55 m wrap-rib reflector antenna ESA Presentation 10/12/2010 Slide 16 3. Large Deployable Antennas The AstroMesh deployable reflector antenna: concept and the m diameter reflector for Thuraya ESA Presentation 10/12/2010 Slide 17 3. Large Deployable Antennas Hinged-Rib Antenna, Harris Corporation 12 m diameter HRAs for ACeS Garuda-1 ESA Presentation 10/12/2010 Slide 18 3. Large Deployable Antennas Terrastar 18 m reflector, Harris Corporation ESA Presentation 10/12/2010 Slide 19 3. Large Deployable Antennas Modular Mesh deployable reflector for Engineering Test Satellite VIII, JAXA ESA Presentation 10/12/2010 Slide 20 3. Large Deployable Antennas Hughes SBA (a) one stowed another deployed, (b) vibration test on TDRS-H (two SBAs are stowed on the top of the satellite) ESA Presentation 10/12/2010 Slide 21 4. Critical Review of the state of the art The Japanese modular deployable antenna, patented by NTT (US B2) ESA Presentation 10/12/2010 Slide 22 4. Critical Review of the state of the art The Astromesh reflector, built by Astro (Northrop Grumman Space Technology) RD2: US A of 1997 ESA Presentation 10/12/2010 Slide 23 4. Critical Review of the state of the art The hoop-truss reflector (RD3: US B2) by Harris Corporation ESA Presentation 10/12/2010 Slide 24 4. Critical Review of the state of the art The TAS-I / EGS reflector (developed under ESA contract) ESA Presentation 10/12/2010 Slide 25 5. A New Concept of Deployable Structure The novelty introduced by the present invention is a simplified architecture of the deployable structure, generated by articulated struts, allowing for a modular construction of doubly curved surfaces. Increased flexibility of the design as compared to the prior art. Either a single or multiple-cell architecture can be chosen. Each module has simple kinematics, that allow stowing efficiently and also guarantees a controlled deployment, reduced mass and improved stability and reliability. The shape of each module can be chosen to conform to the reflector shape or remain as a standard module. ESA Presentation 10/12/2010 Slide 26 5. A New Concept of Deployable Structure Six-bar linkage with special kinematics and trapeze shape when deployed Patented concept ESA Presentation 10/12/2010 Slide 27 5. A New Concept of Deployable Structure Six-bar linkage with special kinematics and trapeze shape when deployed Patented concept ESA Presentation 10/12/2010 Slide 28 5. A New Concept of Deployable Structure Six-bar linkage with special kinematics and trapeze shape when deployed Patented concept ESA Presentation 10/12/2010 Slide 29 5. A New Concept of Deployable Structure Six-bar linkage with special kinematics and trapeze shape when deployed h1 b1 d b2 h2 a1 a2 Patented concept ESA Presentation 10/12/2010 Slide 30 5. A New Concept of Deployable Structure Scalable Unit Cell for modular construction (pyramidal architecture) Patented concept ESA Presentation 10/12/2010 Slide 31 5. A New Concept of Deployable Structure Patented concept ESA Presentation 10/12/2010 Slide 32 5. A New Concept of Deployable Structure Patented concept ESA Presentation 10/12/2010 Slide 33 5. A New Concept of Deployable Structure Patented concept ESA Presentation 10/12/2010 Slide 34 5. A New Concept of Deployable Structure Patented concept ESA Presentation 10/12/2010 Slide 35 5. A New Concept of Deployable Structure Patented concept ESA Presentation 10/12/2010 Slide 36 5. A New Concept of Deployable Structure Spring actuated hinge Elastic hinge Patented concept Electrically motorised hinge ESA Presentation 10/12/2010 Slide 37 Many thanks to: Pablo Fajardo Peña Enrique Ballester And the Universidad Politécnica de Valencia For the kind invitation ESA Presentation 10/12/2010 Slide 38
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