I'm sorry, but I have to say I am not impressed with the AZ Science Center. I bought a family membership, which was pretty expensive, we visited a couple of times, and that was plenty. The exhibits are always the same and kind of boring, except for whatever traveling exhibit they may have, and that costs extra on top of your membership! And I was not at all impressed with the Ripley's exhibit. I can honestly say Ripley's was a rip. Last time we were there, some of the cooler things were broken (like the little bike that goes around in a circle).
Overall, it's probably fine for a one-time visit, but I wouldn't waste money on a membership. It gets old fast.