You can also get senior discounts. I agree that you should pick the earliest time you can if you plan on seeing the shuttle and the IMAX film. We ordered tix 2 months ahead, and the earliest we could get tix for was 19:30 (opens at 10). We got there before 10 am and left at 4:30 PM, just to give you an idea of how time flies.
The tickets are close to 25 and some change if I remember correctly. My wife and I paid 51 for two, no discounts.
Go early and buy tickets online!
Under $40. There are promo codes, student pricing, iMAX etc. (iMAX is an extra ticket/event) Best idea is go to their web site and they allow you to go thru a little menu for picking options and buying your tickers. I would not recommend just going there on the day you expect to go as a lot of days are sold out. I would also recommend picking the earliest time you can. The later you go the more chance of it being crouded.
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