Dispelling the myth of robotic efficiency

There is a widely held view in the astronomical community that unmanned robotic space vehicles are, and always will be, more efficient explorers of planetary surfaces than astronauts (e.g. Coates 2001, Clements 2009, Rees 2011). Partly this comes from a common assumption that robotic exploration is cheaper than human exploration (although this isn't necessarily true if like is compared with like) and partly from the expectation that developments in technology will relentlessly increase the capability and reduce the size and cost of robotic missions to the point that human exploration will not be able to compete. I argue below that the experience of human exploration during the Apollo missions, more recent field analogue studies and trends in robotic space exploration all point to exactly the opposite conclusion.