Is there such a thing as a purely serious science-fiction movie? Stanley Kubrick's 2001: A Space Odyssey comes close, and probably strikes many people as an awful bore, yet there's undeniable wit in the iconic spaceships dancing to On the Beautiful Blue Danube, and in the deadpan directives of the killer computer HAL. Maybe Ridley Scott's Alien would count, if the titular beastie never showed up to kick off the haunted-house chills. British director Danny Boyle's new film, Sunshine, on the other hand, definitely qualifies as serious, playing very much like Alien without the alien.

The grim space thriller follows a crew of astronauts trying to reignite our dying sun with a bomb in the year 2057. Handily enough, this will save the human race from extinction. Until an implausible last-minute twist, the crew faces challenges strictly technical and ethical: repairing the ship's shield and deciding who should get the last of the oxygen. Theirs is the second vessel named Icarus to attempt the mission, and as things begin to go wrong, all of human endeavor seems meaningless, a futile flight too close to the sun.

Boyle, who directed the zombie picture 28 Days Later, was once sought to helm the fourth movie in the Alien franchise, and it's clear he could have knocked it out of the park. Sunshine is realistically claustrophobic, and employs a kind of subliminal editing to ominous effect. As in Alien, there is convincing technology and evocative visions of the alien planet, in this case that familiar big ball of fire. The sunshine itself is rendered with anything but familiarity, whether simmering on the molten solar surface, reflecting off an actor's eye in close-up or filling the screen with white-hot brilliance. Inscrutably beautiful and pitiless, this life-giving force clearly moves the astronauts to thoughts of God.

Among all this reverence, you keep waiting for something really dramatic to happen: a clash of personalities, a close encounter of any kind. There are angry quarrels and losses of faith, but for the most part, our noble heroes predictably slog on. This reduces the tension to the dry calculus of survival, an Apollo 13 disaster that hasn't happened yet. It doesn't help that none of the characters is given a back story, including physicist Robert Capa (28 Days Later's Cillian Murphy). Despite narrating the film's opening with morbid pathos, he's just another boring true believer, like the spaceman in 2001. This movie about killing heat will prove emotionally cold to most audiences expecting the soapy fun of Stars Trek and Wars, but it's still a compelling epic of human endurance. Kubrick would be proud. R. .

Fox Tower, Eastport. Call theaters for additional showtimes.