BENGALURU: India’s Aditya-L1 satellite has marked a significant milestone as the Aditya Solar wind Particle Experiment (ASPEX) payload initiated its operations, shedding light on the mysteries of solar wind, Isro said on Saturday.
ASPEX, equipped with cutting-edge instruments including the Solar wind Ion Spectrometer (SWIS) and STEPS (SupraThermal and Energetic Particle Spectrometer), is operating seamlessly.
“The SWIS instrument, activated on November 2, has demonstrated optimal performance in measuring solar wind ions, notably protons and alpha particles. With two sensor units providing a remarkable 360° field of view each, SWIS operates in perpendicular planes, offering detailed insights into solar wind behaviour,” Isro said.
It added that a sample energy histogram from November 2023 showcases variations in proton (H+) and alpha particle (He2+) counts, providing a comprehensive snapshot with nominal integration time.

The directional capabilities of SWIS enable precise measurements, contributing significantly to unraveling longstanding questions about solar wind properties and their impact on Earth.
The observed change in the proton and alpha particle number ratio by SWIS holds promise in indirectly predicting the arrival of Coronal Mass Ejections (CMEs) at the Sun-Earth Lagrange Point L1. The enhanced alpha-to-proton ratio serves as a sensitive marker for the passage of interplanetary coronal mass ejections (ICMEs) at the L1, playing a crucial role in advancing space weather studies,” Isro said.
As the international scientific community eagerly anticipates further exploration of the collected data, ASPEX stands poised to unveil a wealth of knowledge about the enigmatic solar wind and its implications for our planet.
Researchers are optimistic that these findings will contribute significantly to our understanding of solar phenomena and enhance space weather forecasting capabilities.