Simon Kovalic is an agent with the CID.
In this context, that acronym breaks down as the Commonwealth Intelligence Directorate, which is the secret service for the Commonwealth of Independent Systems (CoIS). That organization is one of the two interstellar governmental systems being discussed in these adventures taking place roughly (I am led to believe) five centuries in the future [could be wrong]. The other government is the Illyrican Empire. As we learn quite quickly, the latter is apparently always on an expansionist footing, something the CoIS is very much against. While there are occasional skirmishes between the two and the threat of outright hostilities is never far from anyone's mind, when we join Kovalic and his team in the first recorded adventure, there is a Cold War between them.
Kovalic holds the rank of Captain in the CID and has been an operative for quite a few years before we start to follow him. He will find a promotion as a reward for his services but the work stays the same; another planet with another problem that he must resolve, usually with the help of a "covert-ops team of misfits".
Those teammates consist of:
Sergeant Tapper is a colleague who has worked with Kovalic for twenty years and might be now in his sixties or even older but who was still no man to mess with and get off easily.
Lieutenant Aaron Page is the intel expert, pretty darn good at gathering a lot of data and making sense of it all, not to mention quite handy in the field as well.
Lieutenant Elijah Brody who is despite his young age an exceptional pilot.
Natalie, aka Nat, Taylor, a Lieutenant Commander who is also Kovalic's wife, or ex-wife as soon as she finds the time to put "a thumbprint on those documents". She is not officially part of the team but still plays vital parts in each adventure.