The shuttles represent 30 year old technology. Most were built more than 20 years ago. If they were cars they wouldn't get an RWC.
If the Americans want to continue with meaningful space research, they have to cut their defence budget and spend the money on developing a replacement.
Having said that, space research will always be very, very dangerous. The Americans have become so good at managing the considerable risks that we tend to take it all for granted.
