The museum itself is free but not worth going to, the exhibits are all in one small space and it's mostly interactional videos describing various aspects of space, most of the 'exhibits' are for kids, such as a colouring station, an interactive mars rover simulation etc, it will take 10 min to see it all. The main interesting element that is actually worth going there for is definately the shows, especially the one in the chaos theatre, which has bean bags for you to lie and watch the space shows. They are about 30 minutes each.