What is this science fiction image?


This image, drawn in ink on heavy paper, and annotated "3/4 in. connectors," was in a box of papers and files that I shipped from my storage locker in Toronto. It's incredibly familiar, but I have no idea what it is. Anyone recognize it?

Update:
The mystery is solved! It was an icon drawn for a UI for a FirstClass BBS at ConnAd, an ad agency I was CIO at. It was drawn by Tara Tallin, and implemented by Michael Hainsworth! And yes, it was based on Silent Running.