Pradeep Singh

It was 'duty first' for Isro chief S Somnath on September 2, 2023, when he was diagnosed with cancer. After spending only four days in hospital, Somnath resumed duties as India was going to launch one of its most ambitious projects, Aditya-L1.

On September 2, India launched its first space-based solar observatory, Aditya L1. The very day when Aditya L1 embarked on its journey to the Sun, Somnath underwent a routine scan that revealed a growth in his stomach. 

In an interview with Tarmak Media House, Somnath said, "There were some health issues during Chandrayaan-3 mission launch. However, it was not clear to me at the time, I did not have a clear understanding about it."

"It was a shock for the family. But now, I perceive cancer and its treatment as a solution...I was uncertain about a complete cure at the time, I was undergoing the process," he said.

"I will be undergoing regular checkups and scans. But, now I am completely cured, and have resumed my duties," the Isro chief added.

All about Aditya-L1 Mission 

The Aditya-L1 mission is an Indian solar observatory at Lagrangian point L1 for 'observing and understanding the chromospheric and coronal dynamics of the Sun' in a continuous manner. 

The orbit of Aditya-L1 spacecraft is a periodic Halo orbit which is located roughly 1.5 million km from earth on the continuously moving Sun – Earth line with an orbital period of about 177.86 earth days, as per Isro's official release. 

This Halo orbit is a periodic, three-dimensional orbit at L1 involving Sun, Earth and a spacecraft. This specific halo orbit is selected to ensure a mission lifetime of 5 years, minimising station-keeping manoeuvres and thus fuel consumption and ensuring a continuous, unobstructed view of sun.

Placing the Aditya-L1 in a halo orbit around L1 point has advantages as compared to placing in a Low Earth Orbit (LEO) like:

- It provides a smooth Sun-spacecraft velocity change throughout the orbit, appropriate for helioseismology

- It is outside of the magnetosphere of Earth, thus suitable for the "in situ" sampling of the solar wind and particles

- It allows unobstructed, continuous observation of the Sun, and view of earth for enabling continuous communication to ground stations.