Aditya-L1 Attains Successful Halo-Orbit Insertion, A Milestone In ISRO's Solar Observatory Mission Achievement
The chosen orbit boasts an orbital period of about 177.86 Earth days, ensuring a continuous and unobstructed view of the sun.
On January 6, 2024, at around 16:00 Hrs (IST), the Indian Space Research Organisation (ISRO) achieved a significant milestone with the successful Halo-Orbit Insertion (HOI) of its solar observatory spacecraft, Aditya-L1. This intricate maneuver, executed during the final phase, involved the precise firing of control engines to position Aditya-L1 into a periodic Halo orbit situated approximately 1.5 million km from Earth along the Sun-Earth line. The chosen orbit boasts an orbital period of about 177.86 Earth days, ensuring a continuous and unobstructed view of the sun.
The specific Halo orbit parameters selected for Aditya-L1—Ax: 209200 km, Ay: 663200 km, and Az: 120000 km—play a crucial role in fulfilling the mission's objectives. Placing the spacecraft in a Halo orbit at Lagrangian point L1 offers numerous advantages over a Low Earth Orbit (LEO). These include a smooth Sun-spacecraft velocity change suitable for helioseismology, positioning the spacecraft outside Earth's magnetosphere for solar wind sampling, and enabling continuous sun observation and uninterrupted communication with ground stations.
The Halo orbit insertion process commenced as Aditya-L1 traversed the XZ plane in the Sun-Earth-L1 rotating system, demanding precise navigation and control. The insertion maneuver effectively nullified the X and Z velocity components, achieving the requisite Y-velocity for the Halo orbit. This successful insertion not only highlights ISRO's prowess in executing complex orbital maneuvers but also instills confidence for upcoming interplanetary missions.
Aditya-L1, conceived and crafted at the UR Rao Satellite Centre (URSC), embarked on its journey on September 2, 2023, launched by PSLV-C57 from SDSC SHAR. During the Earth orbit phase, the spacecraft underwent five liquid engine burns, progressively expanding its orbital size. The trans-L1 injection maneuver on October 5, 2023, and an adjustment burn on December 14, 2023, ensured compliance with Halo orbit insertion conditions.
The meticulously planned trajectory, featuring a cruise phase lasting about 110 days, culminated in the successful Halo orbit insertion on January 6, 2024. This achievement not only underscores ISRO's technical capabilities but also paves the way for Aditya-L1's mission to continuously observe and comprehend the chromospheric and coronal dynamics of the sun, providing invaluable insights into solar phenomena.
