The mission
Checking out anything of interest in orbit around Jupiter would require something a lot more maneuverable than the Discovery, and using a lot less fuel. The pods were for exploration, not repairs, and Discovery (as I recall) was originally designed and built for exploration and drafted for this emergency secret mission, not specifically built for it.
Of course, we can get into how useful they'd be for exploration, since they obviously don't have a lot of delta-V to work with, and would be completely incapable of landing on a moon.