I saw an hour long interview with a remarkable man. People around the world called him.
He's the most experienced US (british born-he completely looks and sounds british) astronaut with 374 days in space in 6 flights and 22 hours spacewalking in American and Russian spacesuits.
He said he feels better in space while on Earth and on Earth while in space (greener grass thing) because he wants change in his life. He's not religious ; seeing the Earth is an emotional thing, not a religious thing; god is not up there more than in us. When Mir had its collision in 1997, he had perfect silence , a very important moment when nobody on Earth could help them and they had to take care of themselves. On the ISS, he saw a huge pollution in Iraq (pipeline sabotaged) that was hardly reported (which surprised him and made him aware of the insignificance of events).
The ISS could be operated without the use of the Shuttle, if need be, he said. It would then depend on the Russians and of course with fewer astronauts and less science, but Kaleri and him could actually perform as much science (same number of hours) aboard the ISS as a previous crew of three.

He defends man v robots because men have a better way to grasp the context of the environment they study (he gave Jack Schmitt's example);
He says he's an astronaut who goes to space to bring back results, shares what he saw, felt, thought.
Astronauts are more afraid of making a mistake while in space than of the danger of spaceflight.
When he spacewalked for the HST, replacing its brain, when he ended his task, he had tears in his eyes when he realized it all went well and so much was at stake for the global scientific curiosity.
He talked about the tourists in the Soyuz capsules and SpaceShip One; all very much in favor of those initiatives.
He says that tourism in space will work when it will be able to survive and still be profitable after it has its first major accident. He mentioned Bigelow, as a commercial operation acting as a salvage team for a government operated mission. Both the commercial and the government missions could help each other.

Going to Mars: yes it will happen on day but nobody knows when. Radiation in a single Mars flight would be about 3 times the amount of radiation he got in all his 6 spaceflight experiences. He doesn't think that a chemical way of going to Mars is the right way of doing it. A nuclear reactor would be shielded from the crew quarters and that same shield could protect astronauts from solar radiations.

His greatest moment: an ISS spacewalk, with all lights of the station off (he asked for that, especially), in the night side, seeing lights on the Earth (Saudi Arabia oil fields, storms in the tropical zone (lightnings) and the zillions of multicolored stars of the galaxy!

He was a space nut before Apollo 11 and said he was very much impressed by Apollo 8 (considering what had happened in 1967).