India’s Aditya-L1 Space Observatory Prepares for Sun Mission: A Collaboration of DST Institutes
The Visible Emission Line Coronagraph (VELC) with the protective Multi-Layer Insulation (MLI) cover, before it was transported to ISRO for integration with Aditya-L1.
TFP Bureau New Delhi | September 1,2023: India’s Aditya-L1, a pioneering space observatory embarking on a mission to study the Sun, has initiated the countdown for its momentous journey. This ambitious endeavor traces its roots back to early discussions between the Indian Institute of Astrophysics (IIA) and the Indian Space Research Organisation (ISRO) regarding potential observations of the solar corona using homegrown space-based telescopes.
IIA, an autonomous institute operating under the Department of Science and Technology (DST), initially proposed the concept of a “suitable coronagraph” payload, intended to be mounted on a small satellite offered by ISRO. Over time, this concept evolved into the Visible Emission Line Coronagraph (VELC), which remains the primary payload for the Aditya-L1 mission. What began as a modest proposal eventually transformed into a national initiative, characterized by multi-institutional collaboration.
The development of VELC, led by IIA, encompassed a comprehensive process that involved design, assembly, characterization, testing, and integration. This endeavor unfolded at the Centre for Research and Education in Science and Technology (CREST) campus in Hosakote, where a state-of-the-art “Class 10” Clean Room, India’s first on such a scale, was constructed inside the MGK Menon Laboratory. ISRO played a pivotal role by providing mirrors and detectors, while IIA diligently delivered the completed VELC to ISRO on January 26, 2023.
The VELC payload, equipped with 40 precision optical elements, will capture high-resolution images of the Sun’s atmosphere, the corona, from a closer proximity than ever before, all while maintaining a space-friendly temperature of 22 degrees Celsius. Furthermore, Aditya-L1 boasts an ultraviolet imager, two X-ray spectrometers, and four in-situ instruments designed to measure plasma parameters. These instruments originate from various ISRO centers and the Inter-University Centre for Astronomy and Astrophysics (IUCAA), with contributions from numerous other institutions.
One of the distinguishing features of the VELC payload is its capability for multi-wavelength imaging and spectroscopy of the Sun. This feature enables the observatory to delve into the corona’s diagnostics, shedding light on the processes responsible for heating the corona, propelling the solar wind, and understanding the drivers behind space weather phenomena. The payload will also measure coronal magnetic fields and explore the origin, development, and dynamics of Coronal Mass Ejections (CMEs), which are vital to comprehending the solar-terrestrial relationship.
The two primary scientific objectives of Aditya-L1 are to tackle the enigma of coronal heating and to study the propagation of disruptive plasma ejections that can impact satellites and communication networks on Earth. Given VELC’s proximity to the Sun’s surface, its data regarding new coronal mass ejections and other solar eruptions will be indispensable for various Aditya-L1 payloads.
VELC Engineering Team Members in front of the truck which had the VELC all packed and ready to go to ISRO.
The VELC Payload Operations Centre (POC), established at the IIA campus, will receive raw data from the ISRO Indian Space Science Data Centre (ISSDC) and process it to render it suitable for scientific analysis. Subsequently, the processed data will be returned to ISSDC for dissemination. The scientific team at IIA, in collaboration with ground-based field station observations, will utilize Aditya-L1 data from its diverse payloads to gain deeper insights into the intricate links between the Sun and Earth, with a particular focus on space weather impacts. The Kodaikanal Solar Observatory and Gauribidanur Radio Observatory, both affiliated with IIA, will play pivotal roles in this mission.
In a collaborative effort, IIA and the Aryabhatta Research Institute of Observational Sciences (ARIES), another DST institute, have devised an innovative automated algorithm designed to detect Coronal Mass Ejections (CMEs) on board Aditya-L1 using the VELC instrument. This algorithm, a first of its kind, will track the massive gas bubbles interlaced with magnetic field lines, ejected from the Sun, causing disruptions in space weather and leading to geomagnetic storms, satellite malfunctions, and power outages. ISRO has hard-coded this algorithm, marking it as one of the pioneering onboard intelligence algorithms for such a purpose, as previous NASA or ESA missions studying the Sun have not attempted a similar feat.
IIA and ARIES have jointly undertaken the characterization of the spectral and continuum channels of the VELC instrument and have implemented advanced machine learning techniques for CME detection in coronagraph images. Furthermore, they are engaged in theoretical studies, including numerical simulations of solar oscillations and coronal mass ejections, providing essential insights for interpreting data collected by Aditya-L1’s instruments.
In a collaborative effort, ISRO and ARIES have established the Aditya-L1 Support Cell (AL1SC) at ARIES. This support cell serves as a community service center, assisting guest observers in preparing science observing proposals and analyzing science data. AL1SC equips users with tools and knowledge in solar physics, enabling them to comprehend, download, and analyze data from ISSDC/ISRO. Workshops held across the country by AL1SC aim to familiarize students with solar processes, ongoing challenges, the Aditya-L1 mission, and observational data analysis.
The Aditya-L1 mission, a testament to India’s prowess in space exploration, brings together a dedicated team of scientists and researchers. Prof. R. Ramesh, from IIA, serves as the current Principal Investigator (PI) of the VELC project, leading a solar astronomy group comprising 15 faculty members and around 20 students, who have contributed significantly to the development and delivery of VELC to ISRO. Prof. Raghavendra Prasad, the former PI of the VELC project, played a pivotal role in the design, assembly, characterization, testing, and integration of VELC at CREST, Hosakote.
Additionally, Prof. Jagdev Singh, along with his team, was instrumental in proposing the initial coronagraph concept during early discussions about solar corona observations. Prof. S.P. Rajaguru, Prof. B. Ravindra, Dr. Piyali Chatterjee, Dr. Jayant Joshi, Dr. C. Kathiravan, Dr. Wageesh Mishra, Dr. K. Nagaraju, Dr. Vmareddy Panditi, Dr. Tanmoy Samanta, Dr. Ebenezer Chellasamy, and Dr. Manjunath Hegde, constituting a total of 15 faculty members and approximately 20 students in the Solar Astronomy group at IIA, have made invaluable contributions to this mission.
S. Nagabushana, S. Kathiravan, Amit Kumar, and P.U. Kamath from IIA have played essential roles in mechanical, electronics, and component assembly and testing of VELC. They were accompanied by a team of engineers and scientists from IIA who have been actively engaged in every stage of VELC’s development. Dr. Sasikumar Raja and Dr. Muthu Priyal lead the satellite integration activities and data pipeline development for VELC, respectively.
Prof. Dipankar Banerjee, the Director of ARIES, and Dr.Vaibhav Pant, have nurtured the Solar Physics group at ARIES into a 15-member independent solar physics group, fully prepared to utilize data from Aditya-L1. Together with Dr. Ritesh Patel, they designed the groundbreaking automated algorithm for CME detection on board Aditya-L1.
Furthermore, Dr. Krishna Prasad Sayamunthala, along with 13 PhD students and Postdocs at ARIES, are conducting extensive research in various areas of solar physics related to the Aditya-L1 mission. This collaborative effort between DST institutes, ISRO, and dedicated scientists, exemplifies India’s commitment to advancing our understanding of the Sun and its profound impact on space weather and our daily lives.
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