It looks like the Spell Compendium version dropped the saving throw alogether. Summarizing...
Breath Weapon (Su): A space drake has one type of breath weapon, a pulse of 6 force missiles usable once every 1d4 rounds. These pulses can strike up to six creatures, no two of which can be more than 30 ft. apart. It can direct more than one pulse at a single target, if desired. Each pulse unerringly strikes its target, dealing 2d6 points of damage. The missile then explodes in a 5-foot burst of force that deals half this amount of damage to any creatures adjacent to the primary target.
The missile strikes unerringly, even if the target is in melee or has anything less than total cover or concealment. The space drake cannot single out specific parts of a creature, but can target and damage unattended objects.