We booked our tickets online and upfront as we got a good deal with the price. The museum was open 10am – 5pm and we didn’t have a specific time slot but got there around 10:30am. The queues were so long, they were even longer for people with pre-booked tickets! The queues outside were an unorganised mess. I would recommend going here but I would not recommend pre-booking tickets, the ticket queue to purchase on the day was $33 for adults and only a little bit more than what we paid. That queue went down so much quicker than ours! Loved seeing the BA Concorde and the space shuttle, they were both incredible to see seeing as though I have never seen either in real life! The Intrepid ship is rather impressive itself too.