I must also point out that there have been many instances where proponents of individual missions have downplayed the technical difficulty and risk of their individual mission, or grossly underestimated the cost and effort involved to solve the problems, in order to gain "new start" funds for particular project. Everyone knows that, once started, any given mission is nearly impossible to cancel, so the goal becomes that of getting started, no matter what has to be said or done to accomplish it. I am speaking here not only to industry and scientific investigators, but also to organizations within NASA. This is a matter of integrity for our community. NASA managers, the White House, and Congress have seen this behavior too many times, and the Agency has lost a great deal of credibility over the decades as a result. There was a time - I remember it, and many of you will also - when what "NASA" said could be taken to the bank. Anyone here think it's like that today? Show of hands? ... I didn't think so.I have spent a good portion of my time as Administrator trying to rebuild that credibility with more rigorous technical review and independent cost estimating processes. But, folks, we are in this together. We will not be trusted with more funding to carry out great, new, exciting space missions in the future, human or robotic, if we oversell and underdeliver on our commitments today. Across the board, we must be realistic in our assessments of cost and technical risk if we are to be trusted with funds provided to us by the American taxpayer.