Here's the setup I have for a d20 Future campaign I'm planning:
Warfare between the United Earth Protectorate and the rebellion on Saturn has escalated in recent months, leading to supply difficulties on Jupiter's moons. Currently, rebel ships have Europa blockaded and are slowly but steadily pummeling the starbase there. The PCs are recent hires in United Frontier Shipping, a government-owned company which transports critical supplies to blockaded worlds and satellites in the Sol system. Their first mission is to transport 18 tons of medical supplies and 10 tons of food to the base on Europa. Depending on choices made by the players, some of them might be piloting the fast freighter the UFS assigned to them, or they might simply be "passengers", extra security hired in case things are rough on the ground. In the process of running the blockade, their engines are damaged and they are forced to crash land hundreds of miles from the landing site–right in the middle of enemy territory. Luckily, they land in an area which can easily be defended. Most of the NPC crew is killed in the crash or the subsequent firefights, so it's up to the PCs to use every piece of equipment at their disposal to get ahold of replacement parts and get the ship repaired and over to the UEP starbase. After accomplishing the mission, their heroism earns them the use of that fast freighter.