Depending on the science, whatever waves you're detecting might go through the engines to reflect or collect through the sensors, or they could be designed to pick up stuff from behind as well as in front, its sci-fi, doesnt have to make perfect sense!
I love your ship btw, I don't know what any of these scouts are really supposed to look like but I always love to see a good conversion.
Don't have any scouts to share, yet, myself.