Accessing the Lunar Poles for Human Exploration Missions

A squirrel-proof bird feeder is provided including a housing having a cut out formed therein for defining a ledge and allowing access to the interior space. A squirrel guard is provided including a pivot frame residing within a single plane and defined by a pair of linear elongated side bars. At least one dowel is coupled between first ends of the side bars. A weighted bar is coupled between second ends of the side bars and has a weight less than that of an average squirrel. A center of each side bar is pivotally coupled to a central extent of opposite sides of a side wall of the housing. By this structure, the dowels remain level with the bottom face of the housing only when supporting an animal with a weight less than that of the average squirrel. The squirrel guard further includes at least one stanchion each coupled to an associated one of the side bars and a cover plate. The cover plate is coupled to the stanchion such that it resides above the pivot frame. When the dowels support an average squirrel, the cover plate precludes access to the food on the ledge of the housing.