Astronauts who venture into outer space return to Earth saying the experience changed them in profound ways, awakening, or reawakening, their spiritual beliefs.

And filmmakers who venture into space travel brush up against those same themes. Stanley Kubrick's mystical monolith in 2001: A Space Odyssey, George Lucas' new age-y Force stuff in the Star Wars saga - even Mel Brooks' Spaceballs considered humankind's place in the infinite expanse of the universe.

Sunshine, Danny Boyle's beautiful, ultimately incoherent sci-fi thriller, likewise warp-speeds into heavy-duty philosophical spheres. The tale of a last-ditch mission to save the world, Sunshine tracks the eight-person crew of the Icarus II, a ship carrying a seismic nuclear payload that, it's hoped, when detonated on its target, will rekindle a dying sun. Never mind global warming: In the year 2057, the world is freezing, the sky is a gloomy dark, and life on the planet is on a fast track to extinction.

Note that the crew - a physicist (Cillian Murphy), a biologist (Michelle Yeoh), a pilot (Rose Byrne), a navigation officer (Benedict Wong), an engineer (Chris Evans), a communications officer (Troy Garity), a medical officer (Cliff Curtis), and a stoic captain (Hiroyuki Sanada) - is aboard the Icarus II. The first Icarus took off on the same mission seven years before, its signal lost as it approached the solar star that lights our galaxy.

Boyle, using a script from his 28 Days Later . . . collaborator Alex Garland (the novelist also wrote The Beach, which Boyle directed), expertly depicts the claustrophobic world inside the spacecraft, and the strains it puts on the crew. Like the gang in Ridley Scott's Alien, the Icarus team tries to fight off the effects of cabin fever, but tempers flare, tensions rise. When an unexpected discovery (well, not too unexpected for anyone with even a passing familiarity with the genre) threatens to drastically alter the mission, crisis begets crisis, and the shipmates' respective skills and psyches are put to the test.

Visually, Sunshine is spectacular. The design of the craft's interior is wholly convincing, from the greenhouse facility that supplies the ship's oxygen to the viewing room where crew members contemplate the giant fiery orb that they're rocketing toward.

The cast is solid. Murphy, with his pale blue eyes and contemplative vibe, has the biggest role, perhaps, but Australian actress Byrne and Hong Kong star Yeoh provide strong emotional colors, and New Zealander Curtis is deft at bringing a note of Third Act foreshadowing to the proceedings, without hamming things up.

But then what happens? I'm not going to fly into the orbit of Planet Spoiler here, but I will say that Boyle's movie falls apart - narratively, and logically - as the Icarus II itself veers off course.

Sunshine can be seen as a story about science and religion, about the rational mind and the mad. But at a certain point, like a dying star about to pop into eternal nothingness, the movie can't be seen as anything - it just implodes.

Sunshine **1/2 (out of four stars)

Directed by Danny Boyle. With Rose Byrne, Cliff Curtis, Cillian Murphy and Michelle Yeoh. Distributed by Fox Searchlight.

Running time: 1 hour, 47 mins.

Parent's guide: R (violence, profanity, adult themes)

Playing at: area theaters