Chemical propulsion is obsolete to go anywhere other than the moon. Three days - that's acceptable. But for Mars, we need propulsion technologies to get us there in, say, 60 days - then spend whatever length of time we want to spend and return when we want to come home.

After Apollo 17, America stopped looking towards the next horizon. The United States had become a space-faring nation, but threw it away. We have sacrificed space exploration for space exploitation, which is interesting but scarcely visionary.

I was a child of World War Two . I saw films of pilots taking off from aircraft carriers and decided that was the only thing I wanted to do. And it had to be flying from sea carriers. Airfields were not enough.

Gene Cernan Quotes