A.P.J. Abdul Kalam was an aerospace scientist who joined India’s defense department after graduating from the Madras Institute of Technology. He was a central figure in the development of the country’s nuclear capabilities and was hailed as a national hero after a series of successful tests in 1998. Kalam served as India’s president for one term from 2002 to 2007, and died of a heart attack on July 27, 2015.