Frontiers of Engineering Reports on Leading-Edge Engineering from the 2015 Symposium (2016) / Chapter Skim
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Realizing Large Structures in Space--Jeremy Banik
Realizing Large Structures in Space--Jeremy Banik
Pages 55-62
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From page 55... ...
Solar sails reflect photons in the short wave, generating constant propulsion for interplanetary exploration and station-keeping maneuvers. For practical Earth-based applications, communication and radar antennas transmit and receive microwaves for communications, coarse imaging, and object tracking.
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From page 56... ...
Radio frequency missions operate on long wavelengths so precision requirements are not as stringent as for optical missions, but because signal gain scales inversely with the square of wavelength, radio antennas require larger apertures than optical. Once unfolded in space, these structures face extreme temperature swings that can cause large static and dynamic dimensional changes.
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From page 57... ...
high-strain composite mechanisms. These methods have been used successfully for decades, but in very limited form because of the absence of high-strength, high-stiffness carbon fiber composites and robust analytical and test tools.1 1 Two historical space structures that used lower-stiffness glass and aramid fiber composites are the Continuous Longeron Mast of the 1960s and the Wrap-Rib reflector of the 1970s.
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From page 58... ...
TABLE 1 Packaged Size of Typical Precision Space Mirror, Shade, and Antenna Deployed size Stowed size Packaging ratio JWST Primary 6.5 m 4.0 m 1.6:1 Exo-S Starshade 34 m 5.0 m 9:1 SkyTerra-1 Mesh Reflector 22 m 2.4 m 9:1 JWST = James Webb Space Telescope; m = meter. Tension-Aligned Antennas and Optics As more sophisticated computerized testing and analysis tools became available and the use of high-strength carbon fibers in aircraft became prevalent, feasible new space architectures began to surface, enabling the ground testing of the Innovative Space-based Radar Antenna truss in 2007 (Lane et al.
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From page 59... ...
. High-Strain Composite Mechanisms High-strain composites are defined as thin carbon and glass fiber polymer matrix laminate materials used to construct shell structures that undergo large elastic deformations during folding and then release the stored strain energy to enforce deployment.
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From page 60... ...
Rather, they should motivate the continued evaluation of new architectures against all measures of success -- not only structural performance but also cost factors such as ease of ground testing and validation, simplicity of analysis methods, and reduced quantity of mechanical interfaces and unique parts. It is difficult to quantify each key cost factor in the early conceptual design phase, but this is precisely when critical design decisions that most affect cost are made.
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From page 61... ...
bending stiffness, linear mass density Solar array scaling index acceleration load, (Banik and Carpenter frequency, boom 2015) quantity, length, area, blanket areal mass density, total mass Mass efficiency diameter/mass D/m Surface precision diameter/root mean D/RMS square (RMS)
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From page 62... ...
2nd AIAA Spacecraft Structures Conference, January 5–9, Kissimmee, FL. NASA JPL [National Aeronautics and Space Administration Jet Propulsion Laboratory]
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