After years of training [as astronaut], you have great confidence in the technology. When you get in your car, you probably feel safe too, even though thousands of people die in car crashes every year.

Every astronaut flew into space for a living. But while NASA has not solved the security problems, I would not put me back into a shuttle - and no other astronaut. The confidence is shaken.

A person moving in zero gravity feels a pitiful helplessness. One wrong move and you find yourself spinning wildly. Everyone becomes a baby again in outer space, laboriously learning how to walk.

At least believe this many humans, who are interested obviously in this topic. Many of them visited me after lectures and meetings, in hope that I can give concrete answers to their questions. For it was clear: If that does not know it, who is to then know it?

ISS leak is just like on a ship, there are bulkheads that, if there's an emergency, can separate an area that's no longer airtight from the undamaged portion of the station. The former Russian space station Mir actually did once develop a leak, after colliding with an unmanned cargo ship. Everyone survived.

I think for being not unsympathetic that their appearance may also appear, so differently it, must similarly as with animals, which meet us in very different forms, which look somehow harmonious however all. On exactly such forms I would stand.