While “The Astronaut Farmer” purports to be to be about the fulfillment of a man’s lifelong dream, it does more to destroy the illusion than to carry out the fantasy. Hollywood presents the modern day American space explorer: Billy Bob Thornton.

In an age when real life astronauts, such as Lisa Novak, are charged with attempted murder, it is not beyond belief that the Thornton’s character throws a brick through a bank window in one of the film’s opening scenes to vent his financial frustrations. Still, Thornton, best known in recent years for his sleazy roles in “Bad Santa” and “Bad News Bears” — note the repetition of “bad” — is not believable as an earnest former astronaut who was forced to give up his desire to travel into space after his father’s untimely death.

“The Astronaut Farmer” opens with a shot of a vast swathe of desert, with Charles Farmer (Thornton) surveying his majestic ranch, outfitted in his homemade space suit. We hear Neil Armstrong epoch-defining words: “That’s one small step for man, one giant leap for mankind.”

For the most part, the film continues in this cloyingly earnest vein, dedicated to telling its quasi-inspirational story with no jokes beyond the understanding of small children. (Lucky Charms cereal deserves an acting credit for its centrality to the plot.) The Farmers live in a town where everyone knows everyone’s business and the county fair is the event of the season.

Bizarrely, the experience of entering space is downplayed. Farmer leaves the stratosphere, the Lucky Charms make yet another appearance, and then we’re back in Texas. The only inference to be made is that “The Astronaut Farmer” isn’t really about one man’s love of the stars and his desire to experience the unknown; one might argue that it isn’t really about anything.

The film aspires to be an inspirational drama, emphasizing that the united American family can tackle anything. The hollow nature of its interpersonal relationships, however, ensures that “The Astronaut Farmer” has no heart. Farmer’s wife Audie’s (Virginia Madsen) unwavering commitment to fulfilling wishes that are often detrimental to her family is so laughably consistent that it is without depth. The stagnancy of their relationship is further reinforced by the fact that Madsen and Thornton make as well-matched a pair as a Napa Valley wine tasting and a broken bottle of Jose Cuervo.

Admittedly, “The Astronaut Farmer” has a certain forced charm. It features an uncommonly amusing cell phone ring and earns a few other good-natured laughs. Its earnest nature is at times compelling: it is refreshing to see a family film that lacks an ironical mocking of children beneath its surface. Still, filmmakers erred in naming one of the Farmers’ daughters Sunshine—seriously, trying too hard.

In the end, the film’s real problem is Charles Farmer. Farmer is neither despicable nor compelling; he’s not much of anything. His desire for space travel seems selfish. If the film had dwelt in this complexity, it might have been a different (and better) production, but it avoids conflict at all costs. He displays no keen intelligence, and the lackluster treatment of his time in space ensures that even his dream seems hollow.

The way that Thornton plays his character highlights a pervasive disregard for the obvious rule that inspirational films require inspirational characters. The building of a rocket is treated with the emotional weight of building a boxcar derby. No doubt the “The Astronaut Farmer” will be touted as a feel good romp for the whole family. But when astronauts are so ordinary, what’s to feel good about?