Katy,
If you haven't already read
Tom Wolfe's "The Right Stuff" about the original Mercury Seven (or just rent/buy the
movie; very underrated IMO). I can't imagine not believing they were heroes after that read.
As the other poster mentioned Hero needs to be defined but by my definition they generally would top your list (even today going up in that aging shuttle).
~ Rick
PS If you want to get an idea of the book just hang around a chain bookstore with a coffee/latte whatever and read the chapter called "Yeager". It sort of stands alone and was excerpted in I think Atlantic Monthly (or maybe Esquire) before the book came out. (BTW, possible good thread topic: Is a Chain bookstore mostly a library, a place to get coffee and pastry, a place that sells books, or a place to pick up/meet smart chicks/guys?)