
We have lift-off: Time for India’s place in the sun

Summary
Mint looks at the need to study the sun, Aditya L1’s objectives and what others have done to study our nearest starAfter its lunar success, Isro is turning its attention to the sun. India’s first solar mission, Aditya LI, will be launched later this week. Mint looks at the need to study the sun, Aditya L1’s objectives and what others have done to study our nearest star.
So Isro is eyeing the sun now?
Yes. After becoming the first nation in the world to soft-land an object at the South Pole of the moon, the Indian Space Research Organization (Isro) is all set to probe the sun—the largest object in our solar system. Aditya L1, India’s first space-based solar mission, is set to blast off from Sriharikota on 2 September at 11.50 am. The spacecraft, which is carrying as many as seven payloads, will be launched using the Polar Satellite Launch Vehicle. It will take 120 days for the spacecraft to reach its intended home—a halo orbit around the Lagrange point L1, some 1.5 million km from the earth.
Why is it important to study the sun?
The sun is the closest star to the earth at 150 million km away. This hot glowing mass of hydrogen and helium gases is the source of energy for the earth. The sun also frequently registers several eruptive phenomena such as coronal mass ejections. These, along with solar winds, can cause disturbances to the earth’s magnetic field. Changes in space weather can impact our space assets such as satellites. An early warning of such disturbances helps to take preventive action. The sun is also a natural laboratory to study extreme thermal and magnetic phenomena which cannot be replicated on the earth.

What is the objective of Aditya L1 mission?
Lagrange-1 is a point between Earth and the sun where the gravitational pull of the two bodies is such that the spacecraft will remain in the same position without spending too much fuel. Once Aditya L1 reaches its final orbit, it can view the sun continuously. It has payloads to study coronal heating, coronal mass ejections, space weather, particles and fields.
What are the seven payloads?
All seven payloads have been built indigenously. The visible emission line coronagraph will study the sun’s corona and the dynamics of coronal mass ejections. An ultraviolet imaging telescope will study the sun’s photosphere and chromosphere. A solar wind particle analyser and plasma analyser will study X-ray flares. High- and low-energy X-ray spectrometers will observe the sun. The spacecraft also has a high resolution digital magnetometer to study the interplanetary magnetic field at Lagrange point L1.
What are the other probes to the sun?
Space powers have been probing the sun since the 1960s. The Pioneer (NASA), Helios (NASA and German Aerospace Centre), Ulysses (NASA and European Space Agency), Stereo (NASA) and Solar orbiters (ESA) have been studying the space weather, coronal mass ejections, solar winds, magnetic field and cosmic rays. In 2018, NASA launched Parker, a solar probe. In December 2021, it flew through the sun’s corona, becoming the first space-craft to touch the sun. It will study coronal activity in close range.