I really only have vague memories of this show (I would have been 8/9yo while the two seasons were airing on Nickelodeon), but as soon as I read through the post it was immediately popping into my head as I remember that it was one of my childhood favorites during the time it was on TV:
“
Space Cases”
(1996–1997)
Synopsis: “One day at an academy, 7 people sneak aboard a mysterious spaceship. The people consist of 5 students, who are Harlan, the athletic leader from earth; Catalina, the Saturnian rainbow-head with a sonic scream; Bova, the negative sour-pus Uranian who can generate electricity; Rosie, the happy Mercurian who radiates heat; and Radu, the Andromedan with super strength and hearing; the other two people are Mrs. T.J. Davenport, the principal at the academy and Commander Seth Goddard, who is their teacher/commander. While on-board they meet an android named Thelma who informs them that they are on a spaceship that is half living and called the Christa. Just when they meet up they become aware that they are approaching a hole that if they get sucked into, they will be stuck in space for 7 years. They eventually do and along their journey they encounter many hardships and enemies that they work together to overcome. They also meet some new people like Suzee (Catalina's imaginary friend from another dimension who gets pulled into this dimension during a warp, putting Catalina in her dimension; she can read minds and has gills), Elmira (Sponge daughter of Warlard Shank), Warlard Shank (the arch enemy of them), etc.” -
synopsis contributed via IMDB by ‘Bethany’