John Hetlinger left the Navy pilot ranks for aerospace engineering. He succeeded in that field, working for NASA on the Hubble Space Telescope for NASA before retiring in his late 60s.
That's when he got into karaoke, singing at karaoke bars in pleated shorts and pants and nice polo shirts. He's apparently got a thing for polos with toucans, which is kind of sweet.
Oh, but the songs he sings are heavy metal, and Drowning Pool's "Bodies" appears to be one of his favorites to perform: