The Air Force's secretive and lucrative Long Range Strike Bomber (LRSB) program is progressing according to plan, according to a key service official.Assistant Air Force Secretary for Acquisition Bill LaPlante told a Senate panel Thursday, when asked about an increase in the program's unit cost, that the $550 million cost per aircraft was "baked" into the program as a key performance parameter (KPP). "Nothing has changed with LRSB," LaPlante told the Senate Armed Services airland subcommittee. "We completely designed the program…