Kalam served as the Chief Scientific Adviser to the Prime Minister and Secretary of the Defence Research and Development Organisation from July 1992 to December 1999. The "Pokhran-II" nuclear tests were conducted during this period in which he played an intensive political and technological role. Kalam served as the Chief Project Coordinator, along with Rajagopala Chidambaram, during the testing phase. Media coverage of Kalam during this period made him the country's best known nuclear scientist. However, the director of the site test, K Santhanam, said that the thermonuclear bomb had been a "fizzle" and criticised Kalam for issuing an incorrect report. Both Kalam and Chidambaram dismissed the claims.