This entry at Thespacereview.com argues for continued human spaceflight-
The retirement of the space shuttle has sparked a debate about the value of human spaceflight. Some see it as a waste of resources. Robots are better, cheaper alternatives, they say—and robotic missions don’t risk human lives. Others see the ability to fly humans into space as being tied up with national prestige, influence, and soft power. Some argue a reliance on private companies to get Americans into space is ultimately a healthy development. Still others say the only reason to put people in space is to ensure the survival of the species should something happen to Earth—and, in the fullness of time, something will. In short, viewpoints are all over the place.
NASA’s Mars rovers have been a remarkable success story. Designed to cover less than half a mile in 90 days, for example, Opportunity is still going strong after more than seven years and 30 kilometers. The fact is, though, that a human expedition could cover 30 kilometers on Mars—and do so more efficiently—in a day. Robots will become more capable, of course, but if we want to see wide-ranging, thorough explorations of Mars anytime soon, dedicated scientists who accept the dangers will have to go there…