Justin Theroux launches into 'Space'

Tapped to pen script for astronaut romantic comedy at Fox

Justin Theroux is heading to space. The actor-cum-writer is on board to pen a draft of "Space Invader," an astronaut romantic comedy set up at Fox.

Mike Lisbe and Nate Reger sold the project and penned the original draft of the comedy, which centers on a man who decides to go to space after he suspects that his longtime girlfriend, an astronaut, is cheating on him with another spacewalker. Will Arnett is attached to star.

Davis Entertainment, the production company behind comedies like "The Heartbreak Kid," is on board to produce with Principato/Young. The project originally was set up at Fox Atomic before migrating to big Fox after the shuttering of that division.

The UTA- and 3 Arts-repped Theroux, who could potentially direct the title as well, has been honing his writing chops. He penned the comedy hit "Tropic Thunder" at Paramount and wrote the upcoming Marvel/Par pic "Iron Man 2."

He's also on board to produce "Air Guitar Nation," a feature remake of the well-received doc.