Nobody deserves anything — 180 Proof

Even criminals who committed heinous crimes?

Reality on the other hand should have something unchangeable, from which we can derive a set of rules. — Mersi

That's why right from the start, the ancient philosophers had lain down rules on talking about the real. Strip it down to bare minimum -- remove complex or composition of the real. After you've reduced it to "stuff" -- in the process called reductionism -- you get the most fundamental block of reality which is unchanging and indivisible.

Or, have we learned that (being human), and looking at our past history of trying to establish colonies, can we justify the effort of trying to establish a colony anywhere in space? — Don Wade

First of all, I don't think you can establish a colony on Mars. Colony is a political and economic move done by a government under one nation. If Mars could be "colonized", all nations should have an equal shot at it. So the entire Earth colonizing Mars.

When you say "our past history", did you have a specific country in mind?

I ask: Under which circumstance could objective reality remain inaccessible to us?
What fundamental properties (or flaws) must we accuse of our cognitive faculties to justify this assumption? — Mersi

The fundamental property that our cognitive faculties have is that we cannot look at an object, for example, without the meaning attached to it. We can't have a blank slate and perception at the same time. It's one or the other. We can't look at a chair without any understanding, whatsoever, what that object is, and even that it is an object.