Visible Emission Line Coronagraph (VELC), the primary payload on board India’s first dedicated scientific mission to study the sun, Aditya-L1, will be sending 1,440 images of the sun every day to ground stations.
VELC, developed by the Indian Institute of Astrophysics (IIA), Bengaluru, will be able to observe the corona continuously from the Lagrange point 1 (L1) of the sun-earth system, which is about 1.5 million km from the earth.
Aditya-L1 is scheduled to be launched by the ISRO on September 2 at 11.50 a.m. from the Satish Dhawan Space Centre in Sriharikota.
“Though Aditya L1 mission will be launched on September 2 there will be a cruise phase of 100 plus days before it reaches the L1 point. Once it reaches that point, the doors will be open from most likely from the first week of January 2024 and we will make continuous observations for using the VELC payload,” Ramesh. R, principal investigator of the VELC payload, told The Hindu.
Prof. Ramesh added that the VELC payload would be sending 1,440 images of the sun in a day.
“The VELC payload has been designed in such a way that every one minute we will be getting an image of the sun and we will be getting 1,440 images per day to monitor the activities of the sun. With so much data, the ground segment should be ready to process these images in real time and within a turnaround time of 24 hours these should be sent back to ISRO so that the data are disseminated to the scientific community and the public,” Prof. Ramesh said.
He said the IIA along with the ISRO centres was ready to handle such voluminous data as all systems were in place.
“We need tremendous computing power for which the IIA is ready and all the software are being tested so that with the minimum overlap time the data from the spacecraft will be downloaded at the Indian Deep Space Network in Bylalu from where they will process the L0 data [Level 0] data and send them to the payload operations centre in the IIA which will be processed within 24 hours and sent back to the Indian Space Science Data Centre for dissemination,” Prof. Ramesh said.
Apart from the VELC payload, there would be six other payloads on board the Aditya L1 whose mission life was five years.
IIA Director Annapurni Subramaniam said the VELC payload was the most important payload on the spacecraft.
“The spacecraft sitting at L1 will take pictures of the sun in various ways so that you can understand more about the properties of the sun as well as the surrounding corona. VELC is a very complex instrument to look at very specific spectral lines,” Prof. Annapurni Subramaniam said.