My first biography written in '73 was not 'Journey To The Moon.' It was 'Return To Earth.' Because for me, that was the more difficult task - disappointment.

Exploring Mars is a far different venture from Apollo expeditions to the moon; it necessitates leaving our home planet on lengthy missions with a constrained return capability.

To send humans back to the moon would not be advancing. It would be more than 50 years after the first moon landing when we got there, and we'd probably be welcomed by the Chinese. But we should return to the moon without astronauts and build, with robots, an international lunar base, so that we know how to build a base on Mars robotically.

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?

Upon stepping foot on the moon, Buzz remarked to Houston, 'Beautiful, beautiful. Magnificent desolation.'

The search for knowledge is a long and difficult task.