First space-based Indian observatory to study sun reaches Sriharikota

TIRUPATI: Aditya-L1, the first space-based Indian observatory to study the sun, has reached the spaceport at Sriharikota, and could be launched in the first week of September, according to sources from the Indian Space Research Organisation (Isro).

The satellite was built at the U.R. Rao Satellite Centre in Bengaluru.

Aditya-L1 will reach a point in space called Lagrange Point 1 — one of the five points where the gravitational pull between the sun and the earth are the same —which is about 1.5 million kilometres from the Earth.

The James Webb telescope of the United States, which has been transmitting spectacular pictures from space, is also stationed at L1

A satellite placed in the halo orbit around the L1 point has a major advantage of continuously viewing the sun without any occultation or eclipses, Isro noted. “This will provide a greater advantage of observing the solar activities and its effect on space weather in real time,” it said.

Aditya-L1 carries seven payloads to observe the photosphere, chromosphere and the outermost layers of the sun (the corona) using electromagnetic and particle and magnetic field detectors.

Four payloads will directly view the sun and the remaining three would carry out of particles and fields.

Isro would be using its trademark slingshot approach to send Aditya-L1 to its spot in space.  The spacecraft will be initially placed in a low earth orbit which will gradually will be raised to a more elliptical shape. As the spacecraft navigates toward L1, it will exit earth's gravitational sphere of influence (SOI), and will be injected into a vast halo orbit encircling the L1 point. This voyage is projected to span around four months.

While it may take time, there are great savings in cost. One of the recent beneficiaries of this approach is the Chandrayaan-3, which  on Monday underwent another orbit reduction manoeuvre and in a near-circular orbit of 150 km x 177 km above the lunar surface.

While Chandrayaan-3 was launched on July 14, and underwent many orbit-raising manoeuvres before entering lunar orbit, Luna-25 of Russia was launched a month later. Both are expected to land on the moon on August 23.