Edgar Mitchell

I theorize that there is a spectrum of consciousness available to human beings. At one end is material consciousness. At the other end is what we call 'field' consciousness, where a person is at one with the universe, perceiving the universe. Just by looking at our planet on the way back, I saw or felt a field consciousness state.

It would be sad if the expertise built up during the 40 years of the U.S. and Russian manned programmes were allowed to dissipate. But abandoning the shuttle, and committing to new launch vehicles and propulsion systems, is actually a prerequisite for a vibrant manned programme.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.