Solar Radiation and Thermospheric Satellite
Solar Radiation and Thermospheric Satellite, also knows as Taiyo or Shinsei-3, was a space probe developed by the Institute of Space and Astronautical Science at the University of Tokyo. The probe was launched on February 24, 1975, from Kagoshima Space Center by M-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.
The satellite had a shape of octagonal cylinder, weighing 86 kg. It orbited the Earth in an elliptical orbit with a periapsis of 260 km and an apoapsis 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.
Instruments
Taiyo had seven science instruments:- Solar X-Ray Detector : Designed to observe solar X-rays in two energy ranges and measure charged particles near the Earth's radiation belts.
- Lyman-alpha Radiation Monitor : Measured solar hydrogen Lyman-alpha radiation to study the Sun's chromosphere.
- Geocoronal and Middle Ultraviolet Radiometers : This system combined the Middle Ultraviolet Radiometer, which measured reflected solar light from atmospheric ozone, and the Vacuum Ultraviolet Photon Counter, which analyzed geocoronal emissions.
- Bennett Ion Mass Spectrometer : Examined ion composition in the upper atmosphere, identifying H+, He+, and O+ ions.
- Retarding Potential Analyzer : Measured ion density and temperature using voltage sweeps across ion traps.
- Electron Temperature Probe : Recorded electron temperature variations, capable of measuring up to 4000 K.
- Gyro-Plasma Probe : Analyzed electron density distribution through high-frequency impedance measurements.