They will increase their numbers exponentially and inexorably inhabit the totality of our galaxy. It may take a few million years, a fleeting moment in cosmic time. [Will We Ever Colonize Mars? (Op-Ed )]

But will these cosmos-colonizing robots — self-replicating robots called "von Neumann machines" after the mathematician John von Neumann — ever be conscious? In other words, will they ever have inner awareness? Will they ever experience the exploration of worlds without end?

Does it matter? I say that it does. I see the question of consciousness as a foundation of the philosophy of space travel. Because if robots become conscious, then the deep reason for humans to go to the stars becomes diminished. Why be burdened with the heavy freight needed to sustain biological life?

On the other hand, if robots can never be conscious, then we humans might have some kind of moral imperative to venture forth. A galaxy colonized by only mentally blank zombies does not seem an ultimate good.

So can robots ever be conscious?