By Lisa Schwarzbaum
Updated February 21, 2007 at 05:00 AM EST
Richard Foreman

In the shimmering first moments of the eccentric, endearing follow-your-bliss drama The Astronaut Farmer, a spaceman appears to be navigating the surface of the moon. Except that he’s on a horse. Wearing a NASA helmet and flight suit. The terrain turns out to be an expanse of farmland. And the homespun astronaut, played by Billy Bob Thornton, is a farmer — named Charlie Farmer.

Charlie was once a bona fide NASA man, but he left the space program to save the family farm. Now his freelance goal is to circle the earth in a rocket of his own construction — an orbiting Field of Dreams, let’s say. And to that end, he’s built a DIY rocket in his barn. The townsfolk are tolerant enough (except at the bank, since he’s defaulting on the mortgage), and his family is downright saintly, considering. Beaming wife Audie (Virginia Madsen, also spousely this week in The Number 23) stands by her man even though Charlie walks a thin line between aspiration and insanity, and the three Farmer kids love their daddy even though he eats dinner in his silver orbit-wear. Only the persnickety, rules-and-regs-hampered government, personified with energetic bluster by indispensable character actor J.K. Simmons (J. Jonah Jameson in the Spider-Man films), objects to Charlie’s project.

It’s either a measure of Charlie’s certifiable craziness or an expression of the gumption and enterprise that’s generally considered all-American that the would-be Rocket Man just can’t fathom why the feds might frown. (Yes, Elton John’s ”Rocket Man” is rented out for the soundtrack.)

Now might not be the ideal time to release a movie about an astronaut with an obsession, but Charlie’s madness is far grander than any ho-hum NASA employee meltdown: Twin filmmaking brothers Michael (he directs) and Mark Polish (he co-writes with Michael) have long been fascinated with the solutions dreamed up by men who don’t fit into the patches of piquant America where they happen to be planted, going back to their strong 1999 Sundance debut Twin Falls Idaho. After teeny indies, this studio release retains the trademark love of warped American gothic that the Polishes share with David Lynch and the brothers Ethan and Joel Coen. But the unexpected streak of yearning sunniness — the Spielbergian touch of boyhood dreams propelling a grown man — gives The Astronaut Farmer a warmth that’s new for them.

Charlie is both maddeningly barmy and a fascinating, ornery mule. And as such, there’s no one I’d rather see orbiting the earth than Thornton, who plays the part with the exact illogical, earnest seriousness required for the mission. By the time Bruce Willis drops by, equally sincere, in a lovely cameo as NASA brass that grins at the actors’ roles in Armageddon, the movie is so serenely in orbit that there’s nothing to do but float along and enjoy the strange, sweet ride. B+