For twenty years now they have tried to build a launcher based on recycling as many ~parts~jobs from the Shuttle program as possible and thus far have flown exactly zero people and exactly zero kilograms of cargo. The Senate doesn't mind, because the STS is a jobs program, not a spaceflight program. (Although it's not like the market for SRBs in particular has been very hot lately given how few of them have been in fact launched, so I dunno. Probably the govt is paying ATK just to keep the plant running so they'll be able to build/refurbish a pair of boosters every two or three years which is the expected STS launch rate.)