Dr V S Arunachalam, former scientific adviser to the defence minister under five prime ministers and the founder-chairman of the Bengaluru-based think tank Center for Study of Science, Technology and Policy (CSTEP), passed away in California on Wednesday (16 August).

He is survived by his wife Meena, children Raghu, Malavika, and Ramu, and six grandchildren.

At the age of 87, Dr Arunachalam was undergoing treatment for pneumonia and Parkinson's before his passing.

"Dr. V.S. Arunachalam’s passing away leaves a major void in scientific community and the strategic world. He was greatly admired for his knowledge, passion for research and rich contribution towards strengthening India’s security capabilities," Prime Minister Narendra Modi said in an X post, also offering his condolences to Dr Arunachalam’s family and well wishers.

Dr Arunachalam studied physics and materials science and engineering in Mysore, Sagar, and at North Wales, where he obtained his PhD (Doctor of Philosophy).

He was then selected as a trainee at the Atomic Energy Establishments and worked there as a research scientist in the Metallurgy Division.

Throughout his distinguished career, Dr Arunachalam worked at institutions such as the Bhabha Atomic Research Centre, National Aeronautical Laboratory (later renamed as National Aerospace Laboratories), and Defence Metallurgical Research Laboratory.

"Dr VS Arunachalam's expertise in metallurgy was vital in shaping India's defence sector, especially during the technology-denial phase post-Pokhran," CSTEP has said.

Dr Arunachalam held prominent positions including Secretary, Department of Defence Research and Development (Ministry of Defence, Government of India), Director General of the Defence Research and Development Organisation (DRDO), and Scientific Adviser to the Defence Minister, Government of India, from 1982 to 1992.

"I have worked with five Prime Ministers and over a dozen defence ministers of India," he revealed in a DRDO monograph titled From Temples to Turbines An Adventure in Two Worlds.

During his tenure at DRDO, the defence organisation grew significantly, in its budget, in the number of scientists and engineers employed there as well as in technology, from building combat vehicles and indigenous missiles to advanced radars and panoramic sonar for the Navy.

"It was under his guidance that the Light Combat Aircraft program (TEJAS) and the Integrated Guided Missile Program amongst others were initiated. Throughout his life he championed the notion of Atma Nirbhar Bharat (self-reliant India),” The Indian Express said, citing a CSTEP statement.

Dr Arunachalam was awarded DRDO’s Lifetime Achievement Award in 2015 for his outstanding contribution to the field of scientific research and technology.

Alongside his technical expertise, Dr Arunachalam's advisory role was crucial for the country.

"When I assumed responsibility as Scientific Advisor to the Defence Minister at Delhi, my job was not only to inform about science and engineering choices but also to advice on their strategic applications and policy options for the country. Thus, policy — along with science and technology — became a necessity," Dr Arunachalam told the CSTEP in April 2020.

Among the many honours he received for his significant contributions to engineering science and technology are the Shanti Swarup Bhatnagar Award, the Padma Bhushan, and the Padma Vibhushan.

Dr Arunachalam was a Fellow of the Indian National Science Academy, the Indian Academy of Sciences, and the Indian National Academy of Engineering.

Additionally, he was the first Indian Fellow of the Royal Academy of Engineering (UK) and held the position of Distinguished Service Professor (Engineering and Public Policy) at Carnegie Mellon University, Pittsburgh.

He also served as a member of the advisory and editorial boards of several universities and foundations, including the Materials Research Society Bulletin.

In 2005, the CSTEP was established by him with the aim of incorporating innovative approaches using science and technology into policymaking.

The centre's approach would be modelled on the Battelle Memorial Institute in the United States of America.

"CSTEP would like to emulate the Battelle model by focusing on policy issues bolstered by technology studies," Dr Arunachalam told the CSTEP in 2020.

"CSTEP," he said, "is an active proponent of driving technology to tackle policy and developmental challenges."