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.
You don't have time to do any project, because you actually can't do a project - you can only take action steps.
There's a subtle but critical difference between something that is long term and something in the category of 'someday/maybe'. Either a project is an open loop to close, as soon as possible, or it is not.