Arunachalam worked as a scientist at the
Bhabha Atomic Research Centre,
National Aeronautical Laboratory in
Bangalore, and
Defence Metallurgical Research Laboratory in
Hyderabad. He was the head of the
Defence Research and Development Organisation (DRDO) for about ten years in the 1980s. During his tenure the budget of DRDO increased eightfold, and he is credited with being able to get over both bureaucratic and financial hurdles. He initiated major defence projects like the Light Combat Aircraft and the Integrated Guided Missiles programmes. Arunachalam served as defence scientific advisor to the
Defence Minister of India between 1982 and 1992, serving ten defence ministers and five
prime ministers, and as secretary, Department of Defence Research for the
Government of India. He advised the government on the definition, assessment and review of a number of major technological and societal programs such as optical fiber communications for India, development of indigenous iron and steel technologies, scientific and technological missions for the country to eradicate illiteracy, infant mortality etc. He also advised the government in the area of graduate education in engineering. Arunachalam was a collaborating professor of engineering and public policy at the
Carnegie Mellon University, and an honorary professor at the UK's
University of Warwick. He was a member of the
Defence Research & Development Service (DRDS). ==Awards==