Here in pricey Silicon Valley, it's great to hear that a cool place is still open for free. A penny saved is a penny earned. So why not?! America has many great things to see. Big land area, and years ago, had more than sufficient cash flow, good thing the government invested a lot on infrastructure . Because of this, there are beautiful places to visit that the whole family can enjoy at no cost. Some museums, parks, beautiful piers, well maintained beaches, etc. And places like NASA too. A part of the NASA Ames Research Center is a great family destination and is open to the general public.
We enjoyed our visit, and although the place is small, it's great for the curious little minds. My little one had fun exploring what they have on exhibit. I did too.