I did let my players take it to Port Wander, then told them it would take so long to repair they would know the campaign was ending when it was ready. They'd get to use it in one session.

That happened, and one of the players, a distant relation to Hax, won his right to take over what he thought was the Calixis Sector. Instead, he got the Jericho Reach and had to deal with Tau, Chaos, and Tyranids or face a firing squad. With that, the campaign ended.

Battleship? No. I ran this one, and yes the PCs had those thoughts and desires, and no I didn't blow it up or squash their itsy-bitsy dreams. I just threw monkey wrench after monkey wrench into their dreams until they gave up on it. There are already plenty of monkey wrench suggestions in the previous posts. Use them all. Your players will come up with even more wonky ideas. Disappoint them. They need some disappointment in their lives. You let them adventure across sectors, conquer planets, defeat alien hordes, and become heroes to millions. They can find solace in that.