Depending on the outcome of a SpaceX launch later today/early tomorrow, that number could start shrinking considerably (the SLS works, but I don't think anyone

Depending on the outcome of a SpaceX launch later today/early tomorrow, that number could start shrinking considerably (the SLS works, but I don't think anyone at NASA is particularly happy about building it overall - initial designs definitely didn't want to be using solid fuel boosters, but here we are).