As we reflect back upon the tragic loss of Challenger and her brave crew of heroes who were aboard that fateful day, I am reminded that they truly represented the best of us, as they climbed aloft on a plume of propellant gasses, reaching for the stars, to inspire us who were Earthbound.

Does it make sense for the U.S. to expend hundreds of billions of dollars to mount a new Apollo-style program to return to the moon? Or have we blazed that trail? Shouldn't we help other nations achieve this goal with their own resources but with our help?

I would rather people understand that there is a very, very fortunate American who was given the opportunity, and was in the right place at the right time to have the moment of a lifetime. My mother was born - her name was Marianne Moon. And she was born in 1903, the year that the Wright Brothers first flew.

Everyone who's been in space would, I'm sure, welcome the opportunity for a return to the exhilarating experiences there. For me, a flight in a shuttle, though most satisfying, would be anticlimactic after my flight to the moon. Plus, if I pursued a flight myself, people would think that was the reason I am trying to generate interest in public spaceflight. And that's not the purpose - I want to generate interest in long-range space exploration.

There should be an international lunar base. That is certainly doable.

A hybrid human-robot mission to investigate an asteroid affords a realistic opportunity to demonstrate new technological capabilities for future deep-space travel and to test spacecraft for long-duration spaceflight.

You need propellants to accelerate toward Mars, then to decelerate at Mars, again to re-accelerate from Mars to Earth, and finally to decelerate back at Earth. Accordingly, the mass of these required propellants, in short, drives our need for innovative launch vehicles.