The Principal Scientific Adviser (PSA) is the chief advisor to the government on matters related to scientific policy. It is currently a Cabinet Secretary level position created in 1999 by the Atal Bihari Vajpayee government. The first appointed Principal Scientific Adviser was A. P. J. Abdul Kalam. This was followed by Rajagopala Chidambaram who held the rank of a Minister of State and was the PSA for 16 years. The current PSA is Ajay Kumar Sood.