Why is apj Abdul kalam called as misille man of India?

A.P.J. Abdul Kalam is called the "Missile Man of India" due to his pivotal role in India's missile development program, particularly during his tenure at the Defence Research and Development Organisation (DRDO) and the Indian Space Research Organisation (ISRO). He was instrumental in the successful development of the Agni and Prithvi missiles, which significantly enhanced India's defense capabilities. His contributions to science and technology earned him national recognition and respect, making him a prominent figure in India's journey towards self-reliance in defense.