What exactly was the Dark Star's mission?

Question

Dark Star appears to be flying through space nuking "unstable" planets for the sake of humanity's colonisation of star systems. When the crew chooses the Veil Nebula, is this completely at random? Or are they choosing planets from a prepared list?

Apparently, they target planets which might collide with their suns causing them to go supernova (is that even possible?). Is that in order to save other planets in the same system which might perhaps be habitable? What exactly was Dark Star's mission?

(I realise that the movie is a satirical comedy :))

Answer 1

According to the wikipedia article for "Dark Star", their mission is pretty much as you've already described it, to destroy unstable planets that might threaten future colonization.

Later in the same article it describes the ship as being "On their way to the next target" when they encounter the asteroid storm that bollixes everything up, so I would presume they are working from either transmitted data or a prepared list.

Answer 2

There was a little more exposition in the film's original screenplay. In short, the Dark Star (and other ships of the same class) were explorer vessels charged with identifying "rogue worlds" that had the potential to interfere with future colonisation efforts.

It is the mid 22nd Century. Mankind has explored the boundaries of his own solar system, and now he reaches out to the endless interstellar distances of the universe. He moves away from his own small planetary system in huge hyperdrive starships: computer-driven, self-supporting, closed-system spacecraft that travel at mind-staggering post-light velocities. Man has begun to spread among the stars.

Enormous ships embark with generations of colonists searching the depths of space for new earths, now homes, new beginnings. Far in advance of these colony ships goes a new pioneer: the scouts, the pathfinders, a special breed of man who has dedicated his life to blazing the trail through the most distant, unexplored galaxies, opening up the farthest frontiers of space. These are the men of the Advance Exploration Corps. The task they face is one of unbelievable isolation and loneliness. So far from home that Earth is no longer even a point of light in the sky, they must comb the universe for those unstable planets whose existence poses a threat to the peaceful colonists that follow. They must find these rogue planets -- and destroy them. Among these commandos are the men of the scoutship Dark Star.

What sort of instabilities were they worried about? Mostly orbital irregularities, apparently.

BOILER: Hey, Doolittle, here's one. An unstable planet. 85% probability of an unstable planet in the Veil Nebula that will probably go off its orbit and hit a star.

and

BOILER: There she is. Definite 99%-plus probability that the planet is going to deviate from its normal orbit in another twelve thousand rotations. It'll spiral in toward its sun, and --

PINBACK: Eventual supernova.

DOOLITTLE: Good stuff. Let's vaporize it.