Medium-energy electron spectrometers on Macao Science Satellite-1

The Macao Science Satellite-1 is a two-satellite constellation specifically designed to study the geomagnetic field and particle radiation environment in low Earth orbit, particularly in the South Atlantic Anomaly region, with a low inclination orbit. Each of the two MSS-1 satellites carries a medium-energy electron spectrometer (MES). The MES sensor heads are based on pinhole imaging technology, which can simultaneously measure 50-600 keV electrons incident from nine directions with a field of view (FOV) of 180 degrees x 30 degrees. The two MESs can realize the pitch angle coverage of medium energy electrons at most positions in the orbit. The MSS-1 A/B MESs can realize direct observation of precipitating electrons and electrons near their loss cones. It can help to study the electron generation mechanism in the inner radiation belt and quantify the precipitation of magnetospheric energetic electrons. Combined with the geomagnetic index, solar wind parameters, interplanetary magnetic field conditions, etc., it can also help to build a dynamic evolution model of energetic electrons in the near-Earth space, to realize the early warning and prediction of space weather based on the observation data, which can provide safety for spacecraft and astronauts in the near-Earth space.