New Delhi: India's inaugural solar mission, Aditya L1, has achieved a significant milestone by successfully completing its fourth Earth-bound maneuver in the early hours of Friday, according to the Indian Space Research Organisation (ISRO).

As a result of this maneuver, the satellite has entered a new orbit with dimensions of 256 km x 121973 km. The critical maneuver was closely tracked by ISRO's ground stations in Mauritius, Bengaluru, SDSC-SHAR, and Port Blair. ISRO shared the latest development regarding this ambitious mission on social media, stating, "The fourth Earth-bound maneuver (EBN#4) has been performed successfully. ISRO's ground stations in Mauritius, Bengaluru, SDSC-SHAR, and Port Blair tracked the satellite during this operation, while a transportable terminal currently stationed in the Fiji Islands for Aditya-L1 will support post-burn operations."

Aditya-L1 is scheduled to execute a total of five orbit maneuvers during its journey around Earth, with four of them successfully completed.

Notably, the next maneuver, Trans-Lagrangean Point 1, which marks its departure from Earth, is set for September 19, around 02:00 Hrs. The satellite previously completed its third earth-bound maneuver on September 10, achieving an orbit of 296 km x 71,767 km, while the first was performed on September 3.

India's First Solar Mission

Following the historic landing of Chandrayaan-3 near the South pole of the moon, ISRO launched India's maiden solar mission, Aditya-L1, from the Satish Dhawan Space Centre in Sriharikota on September 2. The satellite carries seven payloads designed to conduct a comprehensive study of the sun. Four of these payloads will observe sunlight, while the remaining three will measure in-situ parameters of plasma and magnetic fields.

Once it reaches its destination, which is 1.5 million km away from Earth, Aditya-L1 will be positioned in a halo orbit around Lagrangian Point 1 (L1).

The mission is expected to be completed in four months. Aditya-L1 will orbit at an approximate distance of 1.5 million kilometers from Earth, directly facing the Sun, which is about 1 percent of the Earth-Sun distance. The primary focus of Aditya-L1's study will be the Sun's outer atmosphere.

ISRO has clarified that Aditya-L1 will not land on the Sun nor approach it any closer.

Lagrangian Points

Named after the Italian-French mathematician Joseph-Louis Lagrange, there are five Lagrange points between Earth and the Sun, where a small object remains stationary if placed there. At these points, the gravitational forces of Earth and the Sun balance the centripetal force needed for a small object to move with them.

L1 Point

To reach the Lagrange L1 point, the spacecraft will be launched using onboard propulsion. This launch will allow it to escape Earth's gravitational influence and proceed toward the L1 point. Subsequently, it will be placed in a large Halo Orbit around the L1 point, which is close to the Sun. ISRO stated that the Aditya-L1 Mission is expected to take approximately four months from launch to reach the L1 point.

The rationale behind studying the Sun, according to ISRO, is that it emits radiation across a broad spectrum of wavelengths, along with various energetic particles and magnetic fields. Earth's atmosphere and magnetic field act as protective shields, blocking harmful radiation wavelengths. Solar studies from space are conducted to detect such radiation.

Primary Objectives

The primary objectives of the mission include understanding Coronal Heating and Solar Wind Acceleration, the initiation of Coronal Mass Ejections (CMEs), near-Earth space weather, and the distribution of the solar wind.