There's really just one thing I can control: my attitude during the journey, which is what keeps me feeling steady and stable, and what keeps me headed in the right direction. So I consciously monitor and correct, if necessary, because losing attitude would be far worse than not achieving my goal.
Chris HadfieldOther anatomical changes associated with long-duration space flight are definitely negative: the immune system weakens, the heart shrinks because it doesn't have to strain against gravity, eyesight tends to degrade, sometimes markedly (no one's exactly sure why yet). The spine lengthens as the little sacs of fluid between the vertebrae expand, and bone mass decreases as the body sheds calcium. Without gravity, we don't need muscle and bone mass to support our own weight, which is what makes life in space so much fun but also so inherently bad for the human body, long-term.
Chris HadfieldThe cool things about space is when you put your pants on here, you can put them on two legs at a time.
Chris HadfieldDo your homework in advance about the actual travel details so transportation issues do not define your holiday.
Chris HadfieldImbibe three or four times as much water as you think you need and skip at least one, if not two meals, when you are travelling. You should arrive at your destination feeling slightly hungry and your digestive system reset.
Chris Hadfield