The personality cores were attached to GLaDOS in an attempt to control her, or at least provide some protection against her plans to fill the facility with neurotoxin. The fact that there was an entire bin of failed cores suggests that they tried many variations before finally settling on the ones that were stuck to her in Portal 1 - including the morality core which is apparently the only one that actually stopped her releasing the neurotoxin.
It's hard to say why the Aperture scientists thought that giving her large amounts of useless and inaccurate trivia, or a desire to see space, or a thirst for adventure, would do anything, but that seems to be the extent of what those cores were meant to do to her personality.
It's also odd that they would consider those personality aspects (if you can even call what the fact core does a personality trait) before things like anger, morality or curiousity, but then this is Aperture Science we're talking about, and it's quite possible that they were either proposed by, or inspired by, Cave Johnson himself. In fact, the only one of the defective cores that seems mildly plausible as a useful defence against GLaDOS releasing neurotoxin is
the "idiot" core, aka Wheatley.
