Also, real-world events can be reflected in a strip more easily since there is no long production process between the creation of the strip and its delivery to the reader. An artists can change his mind about the direction of the story right up to the point of publication.
Land on Mars' as a project still comes down to something like 'Call Fred about the Mars budget proposal' that can be accomplished as soon and as easily as any other activity in our inventory of work at hand.