What is Howard Wolowitz's engineering specialty?

Howard Wolowitz's engineering specialty is aerospace engineering.

Howard is the engineering specialist among the central scientists on The Big Bang Theory. He works at Caltech and designs equipment intended for NASA missions and the International Space Station, giving his work a practical focus that contrasts with his friends' more theoretical research.

The character holds a master's degree from MIT rather than a doctorate, a distinction Sheldon frequently mocks. Howard nevertheless becomes the group's most prominent space professional: he works on spacecraft hardware, helps develop a Mars rover, and eventually serves as a payload specialist on the International Space Station.

A common mix-up is calling Howard a physicist because he spends so much time with Sheldon, Leonard, and Raj. His defining scientific identity is different: he is an aerospace engineer, and his spaceflight experience is one of his proudest achievements.