CSES-01 (China Seismo-Electromagnetic Satellite) is the first element of an extended constellation
of LEO (Low Earth Orbit) satellites, dedicated to monitoring perturbations of electromagnetic
fields, plasma and charged particle fluxes induced by natural sources and artificial emitters in
the near-Earth space. One of the nine payloads on board CSES-01 is the Italian High-Energy
Particle Detector (HEPD-01), which is equipped with a silicon tracker and a range calorimeter
to detect electrons (3-100 MeV), protons (30-250 MeV), and light nuclei. Since the launch of
CSES-01 in February 2018, HEPD-01 has already returned valuable information about variations
in the Earth-Sun interaction during geomagnetic-storm transients. One of such events was the
G3-class geomagnetic storm that impacted the Earth’s magnetosphere in late August 2018, causing
a temporary rearrangement of the charged particle environment around the planet. In this work,
the HEPD-01 response to this magnetospheric disturbance is presented on the base of particle rate variation measurements. The study of such events is crucial
to better understand mechanisms taking place during solar events and to prevent their harmful
effects on technological and anthropic systems, as well as on human health. The presented results
confirm the HEPD-01 capabilities in monitoring the near-Earth environment and contributing to
establish a nowcasting/forecasting network in the nearest possible future.