Trips to Mars, the Moon, even orbit, will require that we provide astrotourists with as many comforts from home as possible, including paying each other.
It was interesting to think that the very first liquid ever poured on the Moon, and the first food eaten there, were communion elements.
NASA needs to focus on the things that are really important and that we do not know how to do. The agency is a pioneering force, and that is where its competitive advantage lies.
If we go back to the moon, we're guaranteed second, maybe third place because while we are spending all that money, Russia has its eye on Mars. Landing people on the moon will be terribly consuming of resources we don't have. It sounds great - 'Let's go back. This time we're going to stay.' I don't know why you would want to stay on the moon.
Ray Bradbury is one who is contributing to the understanding of the imagination and the curiosity of the human race.
I really hate to be put in the position of trying to justify something, a decision that was made. I'm a military guy: when a decision is made, I go along with it, whatever the manufactured controversy and criticism.
I think there would be no shortage of applicants to the government astronaut corps to be settlers on the planet Mars. And I think this would be very inspiring.
Can you imagine, in 2030, taking a space cruise on the very ship that carried the first human beings to Mars? I can't believe that people wouldn't line up for that possibility.
By venturing into space, we improve life for everyone here on Earth - scientific advances and innovations that come from this kind of research create products we use in our daily lives.
One of the major problems with long-term deep space human flight is the requirement for radiation shielding.
When the time comes to start building deep space transports and refueling rocket tankers, it will be the commercial industry that steps up, not another government-owned, government-managed enterprise.
I'm sure that there are places in the deserts in Australia that could be similar to where we might want to go on Mars.
My favourite thing to do on this planet is to scuba dive.
American greatness was elevated significantly after Sputnik.
When you go to Mars, you need to have made the decision that you're there permanently. The more people we have there, the more it can become a sustaining environment. Except for very rare exceptions, the people who go to Mars shouldn't be coming back. Once you get on the surface, you're there.
Everyone who's been in space would, I'm sure, welcome the opportunity for a return to the exhilarating experiences there.
The life expectancy of people going to Mars may be decreased by the higher level of radiation that they receive.
My expertise is the space program and what it should be in the future based on my experience of looking at the transitions that we've made between pre-Sputnik days and getting to the moon.
It's time to open the space frontier to citizen explorers.
Space architectures capable of supporting a permanent human presence on Mars are extraordinarily complex, with many different interdependent systems.