The Cube

Higgipedia, over at Gaming All Over The Place has an interesting post about using a 6-parsec cube as a sandbox environment for a Traveller campaign.  The premise is that an area of space is opened to exploration/exploitation via a wormhole and that after this area is populated, the wormhole collapses, leaving the area isolated from outside contact.  This may be the piece I needed to help formulate MTU.