I like visiting museums. I am fascinated by engineering and basically how stuff is made. Recently, while in Chicago, we toured the Museum of Science and Industry. Like everything in Chicago, it was not a cheap visit. 
With so many things to do and see, here are my favorites; interactive exhibits, like the tornado and hot-air balloons from the Science Storms, a
n actual 727 airplane suspended from the building, vintage firetrucks, and displays of vintage & modern aircraft and spacecraft!
Above the basic admission, they offer extra tours, exhibits, and other “add-ons”. A captured German U-boat (submarine) basic exhibit in includes in the general admission, with option to add-on a guided tour. If
you have time, definitely add the tour! Great for children 10+, the tour is informative and just really neat! Two doorways are cut into the side and you walk (almost) the entire length of the boat! It was amazing to see the navigation stations, kitchen, bunk beds, torpedo storage, and so much more!
Our final add-on was the coal mine tour. This is the original and has been a permanent exhibit since 1933. The coal mine is a great family activity, perfect for Children 5 and up. The tour starts in a working coal mine elevator and includes a quick train ride and lots of fun-facts.
There is working equipment that spans old and modern mining techniques.
There were many other exhibits and activities that we wanted to see, but our trip was cut short due to lousy transportation. If you are visiting from a Chicago-suburb, it is much easier to drive directly to the museum and pay to park. Otherwise, you may experience a significant delay on the bus or train. There was an event downtown that resulted in many bus routes being detoured, so we ended up in the worst part of South Chicago for a bus transfer. I would not even recommend walking from the train station at 55th/56th. If you really want to take the bus, or have no other options, the X28 is the best option.
I really enjoyed our visit to the museum and will plan to go back on our next visit to the Chicago area.