so with that, i would like to begin this discussion by introducing nasa chief scientist dr. walid.[applause] >> thank you and thank you are hosting this event because i love this museum. every time i come in here, i am a kid again looking around at all the incredible and exciting stuff and since i have become chief scientist at nasa i have gotten to even nurture that child that much more. so i think it is a great event and a wonderful venue and i really appreciate that. i want to start just by saying a lot of attention has been given in the last weeks, months, years perhaps even to the event that concluded yesterday with the landing of the space shuttle, the safe and successful landing of the shuttle. marking really the turning of a page to a new chapter in human exploration of space. things changed. things evolve but what remains constant and what brings us here today to this room for this conversation is the fact that what remains constant is the courage to explore, the urge to reach out beyond where we are and understand our surroundings and our place in it. it is really ingrain