A purported internal memo sent by Sprint management suggests the carrier is set to launch Apple’s fifth-generation iPhone in early October. “Due to the possibility of a major phone launch in October we are blacking out September 30th through October 15th,” the memo reads, referring to employee vacations which apparently may not be taken between the dates specified. Vacation blackouts are common at carriers during major device launches to ensure retail locations are well-staffed to accommodate increased foot traffic. Numerous reports have suggested that Sprint will launch the iPhone 5 in October, and BGR exclusively reported last week that Best Buy is gearing up to take Sprint iPhone 5 pre-orders early next month.