After the Renegade mission by the crew of the starship Flying Dutchman, the UN Expeditionary Force thought Earth was safe for hundreds of years, at least.

After there was trouble on the home front, and the president had to authorize a nuclear strike on an American city, UNEF decided they did need the Merry Band of Pirates again. 

So, the Flying Dutchman is sent out on a simple recon mission. But for the pirates, nothing is ever simple, and their mission will become Armageddon.