On December 2, 2023, the Indian Space Research Organisation (ISRO) said that the Aditya Solar Wind Particle Experiment (ASPEX) payload onboard India’s first space mission to the Sun (Aditya L1) has commenced its operations and is working normally. Sharing the post on X, the Indian Space Agency said, “The Solar Wind Ion Spectrometer (SWIS), which is the second instrument of the ASPEX payload, is operational.
What is ASPEX?
According to the Indian Space Agency, the ASPEX comprises two instruments, the first being the Solar Wind Ion Spectrometer (SWIS) and the Supra Thermal Energetic Particle Spectrometer (STEPS). The STEPS instruments were operational on September 10, 2023, while the SWIS was activated on November 2, 2023, and has exhibited optimal performance, ISRO informed.
About SWIS
SWIS, utilising two sensor units with a remarkable 360-degree field of view each, operates in planes perpendicular to one another The Instrument has successfully measured solar wind ions, primarily photons and alpha particles, ISRO said in a statement.
“A sample energy histogram acquired from one of those sensors over two days in November 2023 illustrates variations in protons (H+) and alpha particles (He2+) counts. These variations were recorded with nominal integration time providing a comprehensive solar wind behaviour snapshot.
The precision in SWIS directional capabilities facilitates accurate measurements of solar wind protons and alphas, playing a crucial role in unravelling enduring mysteries surrounding solar wind properties, fundamental processes, and their influence on Earth.
Alpha-Proton Ratio
The change in proton and alpha particle ratio observed by the SWIS holds the potential to provide indirect information about the arrival of Coronal Mass Ejections at the Sun-Earth Lagrange Points (L1). The enhanced alpha-proton ratio is considered important because it was regarded as one of the most sensitive indicators of the passage of interplanetary coronal mass ejections (ICME) at the L1, and this is very crucial for space weather studies.
As researchers delve deeper into the collected data, the international scientific community eagerly awaits the knowledge wealth that the Aditya L1 ASPEX is set to unveil about solar wind particles and their implications for the planet.
Aditya Space Mission
Aditya L1 was launched aboard the PSLV-C57 at 11:50 IST on September 2, 2023, from the Satish Dhawan Space Center, Sriharikota, ten days after the landing of India’s third lunar mission to space called Chandrayaan-3. The primary aim of this mission is to study the sun from the halo orbit around the Sun-Earth Lagrangian Point (L1), which is located roughly 1.5 million km from the Earth.
The spacecraft contains seven types of payloads, four of which will be used in remote sensing of the sun and the other three for in-situ observation. The payloads have been built by several laboratories in close collaboration with various ISRO centres.
