...Outer space, once a region of spirited international competition, is also a region of international cooperation. I realized this as early as 1959, when I attended an international conference on cosmic radiation in Moscow. At this conference, there were many differing views and differing methods of attack, but the problems were common ones to all of us and a unity of basic purpose was everywhere evident. Many of the papers presented there depended in an essential way upon others which had appeared originally in as many as three or four different languages. Surely science is one of the universal human activities.

Certainly one of the most enthralling things about human life is the recognition that we live in what, for practical purposes, is a universe without bounds.

I think we need someone in a responsible political position to have the courage to say, 'Let's terminate human spaceflight.'
As a staunch advocate of robotic missions.

I'm one of the most durable and fervent advocates of space exploration, but my take is that we could do it robotically at far less cost and far greater quantity and quality of results.

In a dispassionate comparison of the relative values of human and robotic spaceflight, the only surviving motivation for continuing human spaceflight is the ideology of adventure. But only a tiny number of Earth's six billion inhabitants are direct participants. For the rest of us, the adventure is vicarious and akin to that of watching a science fiction movie. At the end of the day, I ask myself whether the huge national commitment of technical talent to human spaceflight and the ever-present potential for the loss of precious human life are really justifiable.

My position is that it is high time for a calm debate on more fundamental questions. Does human spaceflight continue to serve a compelling cultural purpose and/or our national interest? Or does human spaceflight simply have a life of its own, without a realistic objective that is remotely commensurate with its costs? Or, indeed, is human spaceflight now obsolete?

These days, it's really been uninteresting except when disasters occur.