Dr. A.P.J. Abdul Kalam was an Indian scientist and politician who served as the 11th President of India. He played a pivotal role in the development of India's civilian space program and military missile development efforts. As a scientist, he worked with ISRO and DRDO where he developed ballistic missile and launch vehicle technology. He served as the President of India from 2002 to 2007 and was popularly known as the "People's President."