I know you're making a joke, but it's not funny specifically because of what a piece of shit his dad actually was.
In Jonny Kim's senior year in high school, his dad died in a shootout with the police after the pistol whipping his mom and repeatedly threatening to kill her (in front of their high school age son). This dude joined the Navy a few months later, in large part to get away from an traumatic home life.
The Navy gives its pilots call signs, essentially chosen by that pilot's peers in flight school.
Having already been a SEAL and a doctor, and only being sent to Navy flight school as part of his astronaut training, his peers gave him the call sign "Sidequest."