(stages of growth spiritually; does not pertain directly to age)
The stories with only a light science fiction edge to them will be approachable by fairly young Christians. However, the more hardcore works often deal with protagonists of questionable morality and complex gray areas. These stories are probably best reserved for Christians who have reached at least adolescent maturity.
(things you’ve gone through in the past that may affect the present)
Because of the futuristic nature of the genre, our experience has little direct relationship to the genre outside the universals we all share. A background steeped in humanism or science raise the most red flags, and even these may not be of great hindrance.
Singles or those sexually experienced but not in a currently active relationship (e.g. widows) may have to tread somewhat carefully. For while romance and sexuality are rarely the central focus, the lack of moral standards can lead to promiscuity in the subplots.
Mentorships(close connections with minors or immature Christians)
Your greatest danger here lies with indirect endorsement: that the mentee will pick up a book or movie just because they saw you reading/watching it. So while your association with the genre will raise few questions by the immature, you may have to watch your step if the mentee is likely to imitate you into realms they aren’t ready for.
Culture(the atmosphere of where you work and live)
If you live in an area of loose morality, strong humanism, or where rationalization is predominate, it may be best to avoid science fiction as a whole, since it may reinforce these things.
(what you do for a living/spend majority of time doing)
Because of science fiction’s typical timbre, tread carefully if you work in an environment where cynicism, skepticism of the supernatural, humanism or rationalization reigns supreme, e.g. some science fields. Also those jobs where individuality and distinct purpose are lost (e.g. assembly work) may not be the best match either, as science fiction can lose sight of the value of being uniquely human.