You will need a pass for the weekend...walk-in times apply only for weekdays after 1 PM. The passes are difficult to obtain...check the museum's website for more info.
Pass for what? I went yesterday and just walked in. I do not understand your question Craig.
I went on weeks day and didn't stand any cue. https://nmaahc.si.edu/visit/passes there you will find the passes
You should registrate before visiting. But usually tickets are available for the current day. Probably you will have to wait for one or two hours
I'm not sure. My son secured passes for us. He did say you have to have them in advance so I don't know if you can get them today and visit today.
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