SF is a controlled way to think and dream about the future. An integration of the mood and attitude of science (the objective universe) with the fears and hopes that spring from the unconscious. Anything that turns you and your social context, the social you, inside out. Nightmares and visions, always outlined by the barely possible.
Gregory BenfordSpace travel leading to skylife is vital to human survival, because the question is not whether we will be hit by an asteroid, but when. A planetary culture that does not develop spacefaring is courting suicide. All our history, all our social progress and growing insight will be for nothing if we perish. No risk of this kind, however small it might be argued to be, is worth taking, and no cost to prevent it is too great. No level of risk is acceptable when it comes to all or nothing survival.
Gregory Benford