Re Nobody will want to be a Space Cadet:
Haha! Except me. I want to be one and some in my family already think I am one.
What did they call the young ones in Starfleet Academy? Cadets. Once they were on board, they were crewmen.
http://memory-alpha.wikia.com/wiki/Starfleet_Academy
In Starship Troopers, they were called UCFF Fleet Academy cadets, and I believe they were called crewmen on the ships.
Heinlein also had an excellent juvenile sci-finovel called “Space Cadet” and that’s exactly what they were.
Merry Christmas,FreeQs and Freepers!
Cheers,
Jim