This is my ideas page. If I feel that it isn’t too spoilery to reveal something, it will show up below.
Selection of the Orion’s crew
The crew was chosen carefully from those with the best condition and temperament for long-term exploration.
Much like Star Trek: The Next Generation, crew are allowed to bring family with them. However, this is conditional on them also passing physical and mental testing.
Tegan has difficulty forming friendships because of her abilities, and is befriended by Erica, who is socially awkward for the usual reasons.
No Way Home
Morale suffers later on when the ship is cut off from the only known way home, and someone is incapacitated in a battle with the Siphen.