Just to give a bit more feedback on the adventure these characters are intended for, I'll throw up the players information section of the adventure. Mind you, this information is incomplete, biased, and largely unedited at this time.
In 2398 near the end of the second Human Exodus a colony was launched by Dr. Valencia, a leading Terraforming researcher. Disgruntled by the direction of the Venusian terraformation process, he took his experimental ideas and formed a colony company. With the exodus losing steam only about 10,000 colonists (mostly researchers and scientists) signed onto the charter. However, Dr. Valencia was able to strike a deal with Interstellar Metals which allowed his expedition to share resources with a colony expansion for El Dorado. Almost 100,000 corporate employees were to be dropped off at El Dorado, while the Valencia colonists would continue on to another star.
Upon arriving at El Dorado and taking resupply, the colony ship received a transmission from a disgruntled colonist warning them of the conditions at the colony. A vote was taken and almost all of the 100,000 colonists slated to stop there decided to continue on with the Valencia expedition. Fearing reprisal from the mega corporation and the Federation for breaking interstellar theft laws, the colonists changed their destination to almost 50 light years further from Earth. But system after system they explored proved unsuitable for the terraforming equipment of the Valensia expedition. Finally as supplies were running critically low the expedition found a suitable planet almost 100 light years from El Dorado.
As the expedition was on its last leg when they found the system, they named the new planet “Last Leg”. The main landing site was named Valencia City and became both the largest city on the planet and its capital. Dr. Valencia built twelve terraforming centers around the planet and his experimental methods proved very effective. Within 50 years Last Leg had a 90% earth equivalence rating and a population of almost half a million. The 12 terraforming plants had moved to a maintenance mode, preserving the earth like environment.
By 2466 Last Leg had a population of about 860,000 people and had begun building space flight capabilities to explore the system’s outer worlds. Valencia City had almost 300,000 citizens and a strong education and research center. A stable political system had developed and the planet had isolationist and independent attitudes due to fear of what would happen if the Federation discovered the colony. Last Leg developed a ruling council based or corporate and university administration models that was able to maintain order with the Last Leg Security Force.
Society as a whole was rocked on Last Leg in 2466 when an unknown ship jumped into the system’s L4 Lagrange point. The unidentified ship fled to the L5 jump point and quickly left the system. The ruling council feared that the Federation had discovered their colony and that a follow up mission would arrive in the next year. It was decided to build a space defense force and base at the L4 Lagrange point to meet the Federation ships arriving at Last Leg and to give the colony more leverage in negotiations with the Federation mission.
Late in 2467 an expedition did arrive at the Last Leg defense station. Expecting the formation of unknown ships to begin with diplomacy and investigation, the station charged its weapons as a precaution and hailed the ships. The unknown ships immediately attacked the defense force. The base was devastated by the attack but succeeded in destroying the attacking force. After investigating the debris of the enemy ships it was discovered that they were not from the Federation at all, but some reptilian alien species.
Further investigation and deciphering of recovered data storage revealed more details. The aliens had encountered humans before and translation programs were recovered. The aliens were called Silth by humans and were apparently at war with the Federation. The Silth had mistaken Last Leg as an undefended Federation colony and sought to raid it. Navigation data and records showed that the raid had originated from a Silth extended colony and exploration hub about 30 light years distant.
The council refused to return to the Federation for help with the Silth, and instead greatly expanded the Last Leg Defense Force. Intense propaganda campaigns encouraged people to volunteer, and in areas where insufficient volunteers were available limited conscription filled the voids. A series of gunboats based on an old Federation courier shuttle design were quickly introduced and built. Almost half of Last Legs economy was converted to war efforts in 2468.
By August of 2468 a sizable force of Combat Shuttles capable of short to medium range hyperspace flights were built and crewed. The Last Leg Defense Force organized these into a system defense group and an offensive raider group. On August 19th the Last Leg Council publically announced a plan to preemptively attack the Silth base to prevent another attack on the colony.
This is essentially a similar raid to the Doolittle Raid, only with less time to train the crews, and a far smaller population of experienced crewmembers. The experienced crews are mostly in the wing and squadron command crafts, plus being purposefully held back for the system defense force (to defend the home planet, and to train additional crews).
I've thought about upping the level of the starting characters, but have really liked the idea of keeping them hideously green. I will probably raise the level of the commanders and gunners for the more critical craft in the attack squadron (the missile boats). But the PC's craft is expected to mostly be an armed missile shield for the more mission critical craft.