3. A.P.J. Abdul Kalam:

Avul Pakir Jainulabdeen Abdul Kalam, was the renowned former President of our nation often called as ‘People’s President’. Before becoming the President of our nation, he served in many fields. Basically he was a well known aerospace engineer and he also served as a professor of aerospace engineering.He served as the first Chancellor of Indian Institute of Space Science and Technology at Thiruvananthapuram. Before all that, as soon as he completed his graduation from the Madras Institute of Technology in 1960, he joined as the chief scientist at the Aeronautical Development Establishment of DRDO, reports the Wikipedia. At DRDO, Kalam started his career after designing a small helicopter for the Indian Army.