...Like many others, I am not immune to the excitement of seeing astronauts walking on Mars or the moon. We have walked on Mars so often in our reading—with Dante and Beatrice, visiting the planet of martyrs and heroes; with Ray Bradbury's earthmen, finding ruins and revenants of a vanished Martian civilization; and more recently with Kim Stanley Robinson's pioneers, transforming Mars into a new home for humans. I hope that someday men and women will walk on the surface of Mars. But before then, there are two conditions that will need to be satisfied.
One condition is that there will have to be something for people to do on Mars which cannot be done by robots. If a few astronauts travel to Mars, plant a flag, look at some rocks, hit a few golf balls, and then come back, it will at first be a thrilling moment, but then, when nothing much comes of it, we will be left with a sour sense of disillusion, much as happened after the end of the Apollo missions. Perhaps after sending more robots to various sites on Mars something will be encountered that calls for direct study by humans. Until then, there is no point in people going there.
Doc: I'm a pacifist. Caboose: You're a thing that babies suck on? Tucker: No dude, that's a pedophile.