Take a trio of actresses, give them a fact-based story like this, add sufficient historic distance that a modern audience can convince itself that we're more enlightened than that nowadays and you've got quite a crowd-pleaser of a film on your hands.
(I loved the scene where John Glenn's launch was held up while a NASA flunky was sent to retrace the very journey between the East and West buildings that we'd seen Katherine Johnson take in search of a Colored Bathroom umpteen times prior to this. An easy, cheap bit of point-scoring? Perhaps. I'd prefer to think of it as a good point, well made.)