The project was called BOOMERanG because in the
antarctic there is a circumpolar wind. The balloon
went up, around and back, just like a
boomerang!.
The name for the project came later, and is clearly contrived to match.
Hawking once said that looking at the CMB
was like looking at the face of God.
The boomerang team took one of their sky maps
and convolved with with a picture of a team member
whoose name is Robert. They called it the
face of Bob.