Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Drawing of the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) spacecraft in orbit. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. System breakdown structure of the SPICA spacecraft. Subsystems under the BM are omitted for clarity. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Coordinate system and cut view of the SPICA payload module (PLM). It illustrates the concept of the thermal design in the thermal insulation and the radiative cooling system subsystem. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. (a) Cross-sectional view of the SPICA PLM from three-dimensional model (3-D model). (b) Schematic of the TRICS subsystem corresponding to the 3-D model. It illustrates the location and the interfaces of the main truss assembly, including the truss separation mechanism. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. (a) Mechanical load path of the SPICA PLM in the launch configuration. (b) Thermal load and microvibration transfer path in the on- orbit configuration. The main truss assembly is the critical path in both configurations. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Thermal conductivity of the candidate materials in Table 3 in the temperature range below 50 K. Three specimens of T700QI were prepared from the same prepreg to confirm the variation within the same lot number. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. (a) Relationship between Young’s modulus and strength. Average values with three-sigma error bars are plotted. In the legend of the graph, the suffix “T” attached to the material means the tensile testing result. Similarly, “TL” means the tensile testing result at liquid helium temperature, while “C” means the compressive testing result, respectively. (b) Test results of short beam testing. “L” means the measured result at liquid helium temperature. The values are measurement averages. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. (a) Separation spring for the truss separation mechanism made of low-conductivity carbon-fiber reinforced plastic. There are two holes of diameter 18 mm on its upper and lower surfaces in which a preload bolt of the separation mechanism is inserted to lock the spring. (b) Vibration testing configuration. A dummy mass of 0.9 kg was mounted on the spring, and acceleration sensors were mounted on the mass to measure the transmissibility function. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Functional model of the truss separation mechanism for the separation testing. The separation spring is locked by the retention wire instead of the preload bolt. The separation spring retains a distance of 2 mm between separation planes after the lock is released. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Locations and directions of the separation mechanisms integrated with the main truss assembly seen from the top view (+Z) of the spacecraft. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Analytical model for the truss separation mechanism: (a) thermal conduction model to estimate the heat load of the SIA from the main truss assembly, including the four separation springs and (b) finite element structural model to calculate the natural frequencies of the SPICA spacecraft in on-orbit configuration. The model, excluding the main truss assembly and separation springs, is not shown in (b) although the calculation was conducted with the whole spacecraft model. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS

Date of download: 5/29/2016 Copyright © 2016 SPIE. All rights reserved. Displacement of the main truss assembly calculated as a result of the modal analysis: (a) rotation mode around the Z-axis at 1.14 Hz and (b) translate mode along the Y-axis at 4.84 Hz. Figure Legend: From: Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA J. Astron. Telesc. Instrum. Syst. 2015;1(2): doi: /1.JATIS