I saw this film without knowing much about it, and that's probably the best way to see it, because then you'll get a surprise about what happens later on in the film.
The basic story is about an old Russian satellite failing, and it being so old that nobody really knows how to deal with it, so they speak to the (unwitting) designer (*) of it's guidance system: an ex-Airforce Colonel who was destined to be amongst the first astronauts, until the rug was pulled out from underneath the test pilots, to replace them with animals.
(* He designed the system for SkyLab, and the Russians stole a copy of the plans.)
He seizes the chance to blackmail NASA into (finally) putting his team into space (some forty years late), and there's some interesting moments as they (as senior citizens) have to retrain themselves, surrounded by young astronauts.
There's a sense of fun about this film, and some subtle wry humour (unusual for an American film).