Hanks’s fussiness prompted a bit of eye-rolling. Producer Brian Grazer admits wanting to shout, “Push the f–ing button!” But from the start, Hanks had enlisted everyone on the set in a crusade to make “Apollo 13” a model of historical accuracy. “I felt strongly about us sticking to what really happened. There was enough suspense and drama in the real experience so there was no need to add anything extra.” The result, to hear the east and crew tell it, was the re-creation not merely of a dramatic moment in history but also of the astronaut ethos that once enchanted a nation–that of the fresh-faced flight jockey who does everything by the book and laces life-threatening situations with no more than a “Yup” and a “Copy that, Houston.”

To prepare for their roles, the actors boned up on the literature, attended classes at NASA’s Huntsville, Ala., Space Camp and memorized hours of transcribed conversations between the astronauts and mission control. They also spent days going over a mock-up of the spaceship with Lovell, whose superb book “Lost Moon” (coauthored with Jeffrey Kluger) inspired the screenplay. By the end, every actor could walk like an astronaut, bark like an astronaut and, yes, barf like an astronaut. The part of the training that everyone recalled most vividly involved a windowless, padded KC-135 jet better known by its inelegant nickname, the vomit comet. The KC-135 reproduces the zero gravity of outer space (so faithfully that director Ron Howard persuaded NASA to let him film on board), but it also induces the nausea that accompanies weightlessness. Surviving KC-135 left the actors with an unmistakable cockiness. “We did four hours of zero-G time total,” recalls Bacon. “John Glenn’s flight was just over four hours, so . . .”

But the sum of his training kindled in Bacon–and in his costars–the old sense that the real astronauts were more than mere mortals. “Power, glory, fame-it wasn’t driving the [astronauts] I met,” he says. “It was to push the limits of what man is capable of.” The more the actors learned, the better they recognized the humbling differences between being an astronaut and impersonating one. As Bill Paxton put it, “Astrophysics and orbital mechanics aren’t exactly my specialty. Kevin and Gary [Sinise] and I ended up just looking at each other a lot.” Any of the movie’s viewers over the age of 80 are sure to recognize that feeling. “Apollo 13’s” techno-heavy dialogue rockets us right back to those days in the ’60s when we sat mesmerized before the television while the astronauts and mission control babbled on in English that sounded like a foreign language. This re-creation of the space program as an impressive but largely unintelligible enterprise may be the movie’s most realistic aspect.

The film could not be timed more ironically. Under pressure from Congress, NASA recently announced plans to cut 28,000 jobs. A big, wet $52 million kiss like “Apollo 13” must look mighty good to the space cowboys. Still, “no movie is going to bring back the glamour and the excitement this country used to feel about the space program,” says Hanks. “What I hope this does is give credit to men that many people have not thought about in a while. Those men on Apollo 13 and the men in the station bringing them home were inspirational.” Copy that, space scholar. So’s your movie.