India on Saturday achieved a historic milestone in space as the Aditya-L-1 spacecraft, the country’s space-based observatory designed to study the Sun, reached its final destination approximately 1.5 million kilometres from Earth. The observatory was launched on September 2nd of last year.

Announcing the success of this mission, Prime Minister Narendra Modi said it is a testament to the relentless dedication of scientists who have realised one of the most complex and intricate space missions.”

Modi said he joins the nation in applauding this extraordinary feat.

“India creates yet another landmark. India’s first solar observatory, Aditya-L1, reaches its destination. It is a testament to the relentless dedication of our scientists in realising one of the most complex and intricate space missions,” the Prime Minister said on X.

“I join the nation in applauding this extraordinary feat. We will continue to pursue new frontiers of science for the benefit of humanity,” he said.

President Droupadi Murmu congratulated the Indian Space Research Organisation (ISRO) for successfully placing India’s first solar observatory, Aditya-L1, into its destination orbit, and said the mission will benefit all of humanity.

“Another grand feat accomplished by ISRO! As part of India’s maiden solar mission, Aditya L1, the observatory has been placed in the final orbit and reached its destination at Lagrange Point 1,” Murmu said in a post on X.

“Congratulations to the entire Indian scientific community for this great achievement! This mission will enhance our understanding of the Sun-Earth System and benefit all of humanity,” she added.

Murmu also mentioned that the significant participation of women scientists in ISRO missions “takes women’s empowerment to even greater heights.”

The ISRO, on Saturday, successfully placed Aditya-L1 into its destination orbit, Lagrange Point 1. Lagrange Point 1 (L1) in the Sun-Earth system is approximately 1.5 million kilometres from Earth.

Lagrange points are named after the French mathematician and astronomer Joseph-Louis Lagrange.

Over 125 days of travel, covering 1.5 million kilometres, and with a precise orbit insertion, the Aditya-L1 mission has been successfully parked at an optimal spot in the vastness of space, providing an unobstructed view of the Sun.

Lagrangian Point 1 (L1) is a stable point in space where the gravitational forces of two large bodies, such as the Earth and the Sun, balance the centripetal force experienced by a smaller object, like a satellite. It lies along the line connecting the two larger bodies and enables satellites to maintain a relatively constant position.

The Polar Satellite Launch Vehicle (PSLV-C57) launched the Aditya-L1 spacecraft from the second launch pad of the Satish Dhawan Space Centre (SDSC), Sriharikota, on September 2 of last year. After a flight duration of 63 minutes and 20 seconds, it was successfully injected into an elliptical orbit of 235x19500 km around the Earth.

Subsequently, the spacecraft underwent a series of maneuvers and headed towards Sun-Earth Lagrange Point 1 (L1), escaping the Earth’s sphere of influence. The spacecraft is equipped with seven payloads to observe the photosphere, chromosphere, and the outermost layers of the Sun (the corona) using electromagnetic, particle, and magnetic field detectors.

“Using the special vantage point L1, four payloads directly observe the Sun, while the remaining three payloads carry out in-situ studies of particles and fields at Lagrange Point L1, providing crucial scientific insights into the propagatory effect of solar dynamics in the interplanetary medium,” according to the space agency.

The Aditya-L1 payloads are expected to offer the “most crucial information” to understand coronal heating, coronal mass ejection, pre-flare and flare activities, their characteristics, dynamics of space weather, and the propagation of particles and fields, officials said.

According to ISRO, the key objectives of the mission include understanding coronal heating and solar wind acceleration, initiation of Coronal Mass Ejection (CME), flares, and near-Earth space weather. The mission also aims to gain knowledge of the coupling and dynamics of the solar atmosphere and obtain a deeper understanding of solar wind distribution and temperature anisotropy (non-uniformity in different directions).

Solar wind refers to a continual stream of protons and electrons from the sun’s corona, or outermost atmosphere, while coronal mass ejections are huge expulsions of coronal plasma and magnetic field lines ejected from the sun.

The major science objectives of the Aditya-L1 mission are:

- Study of the Solar upper atmospheric (chromosphere and corona) dynamics.

- Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares.

- Observe the in-situ particle and plasma environment, providing data for the study of particle dynamics from the Sun.

- Physics of the solar corona and its heating mechanism.

- Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density.

- Development, dynamics and origin of coronal mass ejections (CMEs).

- Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.

- Magnetic field topology and magnetic field measurements in the solar corona.

- Drivers for space weather (origin, composition and dynamics of solar wind).