Buzz Aldrin

Instead of planning the retirement of the Space Shuttle program, America should be preparing the shuttles for their next step in space: evolving, not shutting them down and laying off thousands of people.

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.

I am not sure about Bill Nelson. I haven't heard him say, 'Let's junk the NASA plan to send humans to the moon.' He's not about to say that. That would not be very popular.

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.

Whenever I gaze up at the moon, I feel like I'm on a time machine. I am back to that precious pinpoint of time, standing on the foreboding - yet beautiful - Sea of Tranquility. I could see our shining blue planet Earth poised in the darkness of space.

We should've asked China to be a portion of the space station. We should've worked out ways that we can... just give away the technology that we have that puts things up into space, with cooperation up above the atmosphere that's needed to help each other.

I think both the space shuttle program and the International Space Station program have not really lived up to their expectations.

I understand that Detroit was a pretty rough place to grow up in the '70s and '80s.

Not everyone will understand this need for America to lead the world in space.

With his deeds, not only words, President Obama has revitalized our struggling space program.

Before deciding what to do about national space policy, Obama set up an outside review panel of space experts, headed up by my friend Norm Augustine, former head of Lockheed Martin and a former government official.

Having walked on the Moon, I know something about what we need to explore, really explore, in space.