Character Class suggestions:
Rangers : These are as you might figure, military rangers, hunters, etc. type character.
Medics/doctors: those whom have medical skills either in humanistic affairs or military.
Pirates: Scavengers, looters and pillagers whom hunt prey among the stars in their makeshift space vessels, either alone or with a crew.
Bounty Hunters: hunting criminals of all sorts.
Artificers/Smiths/Technology Workers: those whom are technology nerds whom can develop new technology and work on machinery etc.
The Paladins: Heavy duty soldiers whom wear heavy plate armor in space, and are similar to SWAT and other military/police forces sent in on specific missions.
Musicians/entertainers: generally speaking they are a class of people whom enjoy life and have the ability to affect and entertain the populace and people.
Botanic People: Working on plants, poisons, venom and anything with nature, both for medical purposes, military and more.
"Sailors": the definition of soldiers whom travel on the "battleships" of space, with their Admirals and other ranks, they fly among the stars and are capable of managing spaceships.
The ideas i have for now.