We have a great time. Got to take in the launch of a Delta 4 rocket the afternoon of our visit. If you don't do anything else, you have to take in the Shuttle Experience. The Mars exhibit was good. Even though Viator ad says ticket is good for two days, it is only good for one.
What a great day, we upgraded our tickets to a behind the scenes tickets and had a fantastic experience. My wife has always been anti-NASA as a waste of money came away with a different stance, maybe not fully converted but has a better understanding.
Place is great. Staff was good. Tour was really nice but the Viator description was not as clear as I would have liked.