The PC's will be the crew of Space Fleet starships... Starting with the frigate SFS Proteus. As per the rulebook, the following minimum positions are needed;
Class/Subclass
Military/Command (The Captain)
Science/Alien Life
Technical/Any
So, we need at least one of each of the above. The rules also state that typically 60% of a ships crew are Officers and 40% are Enlisted. So, we could have up to six officers. There are no restrictions on alien races.
You can roll up your own characters and post them here. If you have any questions, comments or concerns feel free to ask!