system
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human
[Star Trek] How hard its it to join Starfleet?

My son's dream is to become a Starfleet captain one day and I am not sure if I should encourage him or persuade him to pursue another career. How hard is it to get into the Starfleet Academy compared to say getting into medical school on earth. Then how hard is it to climb up the ranks. I want to support him I just would like to know if it is realistic.
gpt
To become an officer, it's tough. 

Unless you and your son are Federation citizens in good standing, Starfleet won't even look at your son's application until he submits a letter of recommendation from an active, or discharged with honors, Starfleet Captain (or other command level officer). Following that, he'll have to take the Preliminary Starfleet Academy Entrance Exam, which if he passes that test, he'll move on to the Starfleet Academy Entrance Exam. The true entrance exam is actually a series of different, very difficult tests (including the infamous "psych exam") that are only given once a year for any specific Federation system, and, on top of that, it's a competitive exam, meaning only one of the examinees can pass, and be able to attend Starfleet Academy. 

If your son even makes it to Starfleet Academy, he'll be faced with one of the most grueling training and preparation programs in the known universe. He'll be submitted to some of the most stressful and taxing tests ever devised, often structured so that there is no way to succeed; these tests are as much about how the testee handles themselves as they are about succeeding. The washout rate is roughly 60%, and the fatality rate just shy of 5%. 

Compared to the Academy, most Starfleet postings are relatively tame. How fast he'd "rise through the ranks" depends on his specialization; if he's a science or medical officer, it'd be much easier to be promoted, but he'll suffer a ceiling of Lieutenant Commander unless he receives command training, though if he's an Operations or Tactical officer, he could eventually become captain of his own starship, after many, many years of service.

Unless you're a resident of the Pakled system, it is unlikely that your son would be able to become a Starfleet officer through traditional means (statistically, it's unlikely for *anyone* to become a Starfleet Officer through traditional means). However, Starfleet does participate in a great deal of officer exchange programs, which may be a better way for him to get into Starfleet. The problem with this is that you'd have to be a citizen of a non-Federation world. 

What he could also try is to become an NCO, through the Starfleet Technical Services Academy on Mars. This is a much easier way to enter Starfleet, although, to become an Officer, your son would have to perform his duties well above and beyond what is expected of him, and receive a commendation from his commanding officer to be promoted. However, going this way makes it extremely unlikely he'd ever reach the rank of Captain.