Hello Tejasvy,

The prefix to the words aerospace and aeronautical is aero, which derives from the Greek meaning air or atmosphere. Aeronautical is a word whose meaning is the study of flight and whose origin was in the early 19th Century.
Aeronautics deals with flight through the air and astronautics deals with operations of vehicles in space, the word aerospace can be viewed as a broader or more overarching term which considers operations in both air and space. In that sense, aeronautics and astronautics could be considered as subbranches of the broader science or field of study known as aerospace

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