Telescope Co-Alignment Design and Its Performance On-Orbit of Solar Observational Satellite ``Hinode''

Abstract

The three telescopes on Hinode, a highly sophisticated solar observational satellite, must be able to simultaneously observe the same point on the sun in order to ascertain data on the physical mechanisms for activity and heating in the solar atmosphere. To fulfill this mission requirement, the telescopes must remain co-aligned to within 2.0 arcsec under the temperature fluctuations the satellite experiences while orbiting the earth. Hinode consists of two modules and a connecting structure. Most of the structural elements are made of CFRP in order to suppress thermal deformations. In particular, the laminate configuration of the CFRP in the module holding the telescopes was carefully designed in terms of not only its stiffness and strength but also its coefficient of thermal expansion and thermal conductivity. A thermal deformation analysis was performed to estimate the co-alignment drift on-orbit and a thermal deformation test was conducted to verify the estimation. The results showed that the structural design would sufficiently suppress the drift on-orbit. Measurements on-orbit were conducted using the image of the sun, and the measured drift was in good agreement with the estimation.

Correlation between Mount Wilson Classifications to Solar Flares using Solar Dynamics Observatory (SDO) and Hinode Satellites

“…The Hinode satellite comprises the X-ray Telescope (XRT), the EUV Imaging Spectrometer (EIS), and the Solar Optical Telescope (SOT) [23]. The SOT includes the 50 cm aperture inside the Optical Telescope Assembly (OTA) and the camera system inside the Focal Plane Package (FPP) [24].…”