NASA is very expensive to keep running, yes. However NASA performs a lot of important work. They help us understand the world around us. NASA will possibly be the entity that saves human kind if the Earth becomes uninhabitable for us someday and we have to live elsewhere, like for example, a space station or on another planet.
I don't think its a good idea because a lot of people get hurt, and its too expensive and we can be spending all the money that is being wasted to go study things that are not on Earth when we should be saving that money for the environment, and to study things that are on Earth so we can be more careful.
It isn't a good idea to shut NASA down even though they hide information from the public, I think they should keep it running but have a voting system to decide what the public want them to do in space, e.G Do you want NASA to try to explore Mars? Or Do you want NASA to build a space station on the Moon? Ect. Then when they actually accomplish a task like that tell us, not hide it and keep information to themselves in fear of mass rioting.