If you can't afford the addmittstion, can you just make a donation?

At the ticket counter a "pay-what-you-wish" admission is available every day. With this option you can get a general admission ticket that includes all museum halls but does not include special exhibitions, giant screen film or space show.

Hey Gwen I am not sure, about other days, but on Wednesday's you can pay whatever amount you want

Yes but only general admission. But i would recommend you bring extra cash for food.

For the museum there used to be a sign that said "pay what you wish, but you must pay something" That will get you into the museum、but not into any of the special attractions.