Solar Radiation and Thermospheric Satellite (SRATS), also knows asTaiyo ("Sun" in Japanese) orShinsei-3,[1] was a space probe developed by theInstitute of Space and Astronautical Science (ISAS) at theUniversity of Tokyo. The probe was launched on February 24, 1975, fromKagoshima Space Center byM-3C-2 rocket. Its mission was focused on upper atmospheric physics, X-ray and UV solar radiation, and the Earth's ionosphere. Taiyo completed its mission before re-entering Earth's atmosphere on June 29, 1980.[2]
The satellite had a shape ofoctagonal cylinder (or prism), weighing 86 kg. It orbited the Earth in anelliptical orbit with aperiapsis of 260 km and anapoapsis of 3,140 km, at a 32-degree inclination. The satellite's primary goal was to investigate solar X-rays, ultraviolet radiation, and the distribution of ions and electrons in the Earth's upper atmosphere.[2][3]
Solar X-Ray Detector (SXR): Designed to observe solar X-rays in two energy ranges (5.9-9.5 keV, 9.5-11.5 keV) and measure charged particles near the Earth's radiation belts.
Lyman-alpha Radiation Monitor (SXU): Measured solar hydrogen Lyman-alpha radiation to study the Sun's chromosphere.
Geocoronal and Middle Ultraviolet Radiometers (GMV): This system combined the Middle Ultraviolet Radiometer (MUV), which measured reflected solar light from atmospheric ozone, and the Vacuum Ultraviolet Photon Counter (GUV), which analyzed geocoronal emissions.
Bennett Ion Mass Spectrometer (CPI): Examined ion composition in the upper atmosphere, identifying H+, He+, and O+ ions.
Retarding Potential Analyzer (RPA): Measured ion density and temperature using voltage sweeps across ion traps.
Electron Temperature Probe (TEL): Recorded electron temperature variations, capable of measuring up to 4000 K.
Gyro-Plasma Probe (IMP): Analyzed electron density distribution through high-frequency impedance measurements.
Hirao, K. (1976). "Results of observations made by the SRATS (Solar radiation and thermospheric structure) satellite".Space Research XVI; Proceedings of the Open Meetings of Working Groups on Physical Sciences, May 29-June 7, 1975, and Symposium and Workshop on Results from Coordinated Upper Atmosphere Measurement Programs, Varna, Bulgaria, May 29-31, 1975. Berlin, East Germany: Akademie-Verlag GmbH. pp. 235–240.Bibcode:1976spre.conf..235H.
