Aditya-L1 Completes First Halo Orbit Around Sun-Earth L1 Point

The Aditya-L1 spacecraft has successfully completed its first halo orbit around the Sun-Earth L1 point. Launched on 2 September 2023, this Indian solar observatory reached its targeted halo orbit on 6 January 2024. The Aditya-L1 takes 178 days to complete one revolution around the L1 point.

Maintaining the Orbit

During its journey in the halo orbit, the Aditya-L1 spacecraft encounters various perturbing forces. These forces cause deviations from its intended path. To counteract these, two station-keeping manoeuvres were performed on 22 February and 7 June. Today’s third station-keeping manoeuvre has ensured the spacecraft’s continued travel along the second halo orbit around L1.

Complex Dynamics and Precision

Navigating the halo orbit around the Sun-Earth L1 Lagrangian point involves modelling complex dynamics. Understanding the various perturbing forces acting on the spacecraft was crucial. This knowledge allowed precise trajectory planning and accurate orbit manoeuvres. With today’s manoeuvre, the state-of-the-art flight dynamics software developed by URSC-ISRO for the Aditya-L1 mission has been fully validated.

Trajectory Details

The blue trajectory shown in the figure represents the orbit around the Lagrangian point L1. This is a three-dimensional trajectory, projected onto the X-Y plane. The station-keeping manoeuvres (SK#1, SK#2, and SK#3) ensured the spacecraft maintained its required path. The final thruster firing on 2 July (SK#3) placed the spacecraft back in the desired orbit. If the firing had not been accurate, the spacecraft would have followed the green trajectory, deviating from its path. The X-Y axes in the figure are marked in kilometres, with the Lagrangian point L1 at the origin.