Aditya-L1’s final orbit insertion took place today, making it the closest Indian spacecraft to the sun

After traveling through space for more than four months, India’s first solar observatory has arrived at a location around one million kilometers from Earth, known as the Lagrangian Point (L1).

Aditya L1 will be launched into a halo orbit on Saturday afternoon, giving it a clear five years to observe the powerful Sun.

This brings the closest Indian spacecraft to Earth’s nearest star to date, albeit L1 only makes up 1% of the distance and the Sun will still be some 150 million km away. At L1, the spacecraft will remain in a circular orbit without using much energy because of the balance between the centrifugal force of the orbit and the gravitational pull of the Sun and Earth. It will still need to be maneuvered every few weeks to avoid a collision with the four other NASA spacecraft that are near L1, however.

EVERYTHING IS ROUND FOR ORBITAL INSERT
Aditya L1’s seven scientific instruments will all be turned off on Saturday before the Indian Space Research Organization (ISRO) launches the satellite into orbit by firing its thrusters. Performing the maneuver in one go while using the least amount of fuel will be difficulty. If all goes according to plan, it will hold out on turning on all of the payloads for a few more days in order to guarantee a stable orbit with a clear view of the Sun.

Visible Emission Line Coronagraph (VELC), which will be turned on for the first time since the mission’s launch on September 2 of last year, is the focus of attention. Developed by researchers at Bengaluru’s Indian Institute of Astrophysics (IIA), it serves as Aditya L1’s primary payload.

“We will hold off on turning on VELC until the end of January in order to safely block out light from the main disk and collect the weak light of the Sun’s outer layer, known as Corona. That’s the primary objective. According to Professor R Ramesh from IIA Bengaluru, “We haven’t opened its aperture because we didn’t want the mirrors to be affected by the molecular dust or disturbance when thrusters are fired during orbital insertion.”

The payload includes an inbuilt occulter, which is a shield designed to isolate and reject light from the Sun’s disk. Next, the light that remains from the Corona will be examined. VELC maintains its instrumentation at 22°C.

In order to find answers to many of the long-standing mysteries that have perplexed scientists, all seven of the equipment on board will examine various solar areas. These include the origin of solar storms and flares, their effects on space weather, the enormous temperature differential between the solar surface and its outer layer, and many more. “Because Aditya L1 is far from the Sun, it provides VELC with an exceptional opportunity to view the Corona from a wide area, which is where these solar storms actually start,” the senior scientist continues.

EVERY SEVEN PAYLOADS TO BECOME ACTIVE BY THE END OF JAN
At present, the ISRO has an advantage. While the satellite was in orbit, it already established a downlink and began collecting data from the three activated payloads. It is the moment of greatness that Indian astrophysicists have been yearning for. With a scientific apparatus made in the country, they will be able to take a picture of the Sun’s whole disk for the first time.

To enable us to accomplish the research we had in mind, every device on board will have to cooperate with one another. We will have the first-ever whole disk picture of the Sun thanks to the onboard SUIT instrument (Solar Ultraviolet Imaging Telescope). According to Professor Dibyendu Nandi of IISER in Kolkata, “It will strengthen our research to understand the activity on the solar surface and its atmosphere, especially how it influences the space weather, and then predict it accordingly.”

The photosphere and chromosphere of the Sun were visible in the first photograph, taken on December 6 of last year, at a wavelength of 200–400 nm. Using various scientific filters, these layers revealed the sunspots and other locations.

Understanding the Sun is essential, even outside of astronomical studies, as it often releases strongly charged particles that might harm satellite electronics. Coronal mass ejections (CMEs) are enormous expulsions of magnetic energy that interfere with Earth’s geomagnetic fields and potentially malfunction solar panels or scientific equipment on board.