The space center was Fantastic - extremely kid-friendly with lots of interactive things to do and 3-D experiences. Definitely go be a part of this wonderful history and learn more about what's currently happening.
If you are going with Viator tickets - make sure you have tickets in hand. Not the voucher although bring that too - but the voucher will NOT get you in. The ticket window will NOT give you your tickets with the voucher. I had to make a call and have tickets emailed to the ticket window. Since I had called the day before and they told me I was all set to go straight to admissions - I was miffed to get there and not have that be so at all. So my advice is to definitely have tickets in hand!
It would have ben much easier and quicker buying the tickets directly at the center. We arrived early to be able to be there at opening time at 9.00, but had to Wait until 9.30 for the dolphin Tour operator to turn up and give us our tickets.