In a groundbreaking leap for India’s scientific exploration, the Indian Institute of Astrophysics (IIA) has announced a remarkable achievement – the creation, assembly, and successful testing of the Visible Emission Line Coronagraph (VELC). This exceptional instrument is a pivotal component among the seven payloads of India’s pioneering Aditya-L1 mission, exclusively devoted to unravelling the enigmatic facets of the sun.
Collaborating closely with the Indian Space Research Organisation (ISRO), IIA’s tireless efforts culminated in the birth of the VELC at its CREST campus in Hosakote. A monumental milestone was marked as India’s first spacious ‘Class to Clean Rooms’ came to life, providing the ideal environment for the assembly of the VELC.
Aditya-L1, poised for launch from Sriharikota in Andhra Pradesh on September 2, carries a constellation of payloads, including the Solar Ultraviolet Imaging Telescope (SUIT), Aditya Solar Wind Particle Experiment (ASPEX), Plasma Analyser Package for Aditya (PAPA), SoLEXS-Solar Low Energy X-ray Spectrometer (SoLEXS), High Energy L1 Orbiting X-ray Spectrometer HEL1OS, and an enhanced-scope Magnetometer. This intricate symphony of instruments is set to orchestrate an unprecedented symphony of knowledge, blending extensive remote and in-situ observations of the Sun.
Originally conceptualized as Aditya-1 with a vision of a 400 kg satellite bearing the VELC payload, the mission has now evolved into Aditya-L1. This mission’s transformation was prompted by the prospect of placing the satellite in the halo orbit around the Sun-Earth system’s first Lagrangian point (L1), approximately 1.5 million km from Earth towards the Sun. This strategic vantage point ensures uninterrupted solar observations, free from the interruptions of eclipses or occultations.
The VELC, nestled aboard the Aditya-L1 satellite, holds the key to unlocking the secrets of the solar corona. This internally occulted solar coronagraph wields the power of simultaneous imaging, spectroscopy, and spectro-polarimetry, all positioned tantalizingly close to the solar limb. Its innovative design allows for the vivid imaging of the solar corona, making it an invaluable tool for solar researchers.
The fusion of imaging and spectroscopic data acquired by the VELC is poised to revolutionize our comprehension of the solar corona’s dynamics, diagnostic parameters, and even the genesis of coronal mass ejections. The payload’s unique capability to perform Stokes vector measurements in the plane-of-sky and capture white-light images lends a distinctive edge to its scientific prowess.
Beyond the realms of scientific inquiry, the Aditya-L1 mission carries profound implications for our understanding of space weather. By delving into the heart of the sun’s mysteries, the satellite endeavors to enrich our comprehension of the solar corona and furnish indispensable data for space weather forecasts.
While India’s historical success with the Chandrayaan-3 Vikram lander remains fresh in our memory, a new chapter is being written in the nation’s scientific saga. As lunar exploration continues to unfold, the audacious decision to embark on a solar odyssey underscores India’s unwavering commitment to expanding the frontiers of human knowledge. With the Aditya-L1 mission poised to illuminate the secrets of our nearest star, India’s scientific ambitions burn brighter than ever before.