Time was when Hanna-Barbera, Filmation and Krofft ruled Saturday mornings. H-B had a deserved reputation for very crude, simplistic animation, but like most of their shows, this was good, clean fun. Not as good as the original show, but not that bad. Pretty repetitive plots, though. They always run into some would-be conquerer alien, defeat his minions, then take off.
Lucky for Alexandra I wasn't on that rocket ship, though. I would have shoved her out the airlock pretty quickly. In every episode, she always screwed things up for everybody and was basically useless, sometimes doing so by being stubbornly hare-brained and headstrong just when they're back in sight of Earth. Unlike Gilligan, she wasn't well-intentioned. Everything she did was always strictly for herself. She was even worse than Dr. Smith of Lost in Space. Stupid bimbo.