After India’s solar mission, Aditya L1 began its journey towards Lagrange point 1 following a key manoeuvre, it has started studying energetic particles in the solar wind from space and will continue to do so for the rest of its life, a senior astrophysicist said. The study of the solar wind, the continuous flow of charged particles from the sun which permeates the solar system, will be carried out with the help of a device named Supra Thermal & Energetic Particle Spectrometer (STEPS), a part of the Aditya Solar wind Particle Experiment (ASPEX) payload.

“STEPS is now working from space. However, it was not sitting idle earlier. It has started functioning from within the magnetic field of the Earth since September 10 when Aditya was 52,000 kilometres above our planet,” Dr Dibyendu Chakrabarty, professor of Space and Atmospheric Sciences at the Physical Research Laboratory (PRL) said.
STEPS was developed by the PRL with support from the Space Application Centre (SAC) in Ahmedabad.

“During the travel time of four months (till Aditya L1 reaches its destination), it will study energetic particles in the solar wind. The data will help maintain the health and performance of our space assets in a better way,” Dr Chakrabarty told PTI.

The key aim of STEPS is to study the environment of energetic particles from the spacecraft’s position on the L1 point till it will function, he said. “The data from STEPS in the long term will also help us understand how space weather changes,” the space scientist said.

STEPS comprises six sensors, each observing in different directions and measuring supra-thermal and energetic ions. The data collected during the Earth’s orbits helps scientists to analyse the behaviour of particles surrounding the planet, especially in the presence of its magnetic field.

Aditya-L1, launched by the Indian Space Research Organisation (ISRO) on September 2, will go up to the First Lagrangian point, about 1.5 million km from the Earth ISRO on September 18 said on X: “Off to Sun-Earth L1 point! The Trans-Lagrangean Point 1 Insertion (TL1I) manoeuvre is performed successfully. The spacecraft is now on a trajectory that will take it to the Sun-Earth L1 point.” Lagrangian points are where gravitational forces, acting between two objects, balance each other in such a way that the spacecraft can ‘hover’ for a longer period of time.

The L1 point is considered the most significant of the Lagrangian points, for solar observations, which were discovered by mathematician Joseph Louis Lagrange.