There are different levels of membership-- some memberships are currently on sale, most popular is $95. Memberships generally include free parking, free IMAX & planetarium tickets, free admission to special exhibitions.
Admittance is free
They might have different membership prices parking is free if you park over in the park forestpark
I am not sure how much it cost for a membership. I went there for 1 day free admission. Parking is $10 per car.
Thanks! Your answer is awaiting moderation.