There was a book that I read in the 80s... it was about a few kids enrolled in some sort of space fleet academy and they wanted to be ship captains.

I cannot recall much of it except one part where one of the kids failed a test because he forgot to account for a mountain that reached through the atmosphere and ran a spaceship into it while trying to orbit.

Any help would be appreciated. It *might* be something like Spacefleet Academy but that's just a guess.