I was near voting age when this film came out. I went to see it three times and it is still one of my all-time favorites. Would I show it to my 11-year-olds? No. Some of it is too risqué for that age group--the famous sperm scene, but also the Texas barbecue dancer and the "extra-curricular" activities of some astronauts come to mind. Also, the needle test in the New Mexico clinic is too intense for most kids and quite a few adults. As for the language--well, nothing that a tween hasn't heard already, but it's an individual call. The rest, though, is a great American story well told with the help of excellent acting and Bill Conti's score for the ages. I'd say no problem for ages 13 and up.
The question is, will kids care? In our age of global warming and the inexorable rise of China, the Cold War rivalry behind the space program and the can-do attitude of 1950s America really seem to belong to another era. We who remember the Berlin Wall can relate. Our kids, who only know that stuff from history books, may not. Also, at three hours, the movie is very long if well paced. It may be hard keeping the texting generation (except for born candidates to be the next John Glenn or Sally Ride) interested in the story for that long.
Still, remember--our Germans are better than their Germans!