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Spaceflight Isn't Just About Doing Experiments, It's About An Extension Of Human Culture.

When You Have Some Skills But Don't Fully Understand Your Environment, There Is No Way You Can Be A Plus One. At Best, You Can Be A Zero. But A Zero Isn't A Bad Thing To Be. You're Competent Enough Not To Create Problems Or Make More Work For Everyone Else. And You Have To Be Competent, And Prove To Others That You Are, Before You Can Be Extraordinary. There Are No Short-cuts, Unfortunately.

My Optimism And Confidence Come Not From Feeling I'm Luckier Than Other Mortals, And They Sure Don't Come From Visualizing Victory. They're The Result Of A Lifetime Spent Visualizing Defeat And Figuring Out How To Prevent It. Like Most Astronauts, I'm Pretty Sure That I Can Deal With What Life Throws At Me Because I've Thought About What To Do If Things Go Wrong, As Well As Right. That's The Power Of Negative Thinking.

Other 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.

If You Haven't Learned To Ride A Bike By The Time Your Peer Group Has, Then Suddenly It's An Embarrassment And You'll Avoid Opportunities Where You're Expected To Ride A Bike. And Then It Starts Shaping Your Behaviour. Reading Is Much Subtler, But Much More Destructive If You Have Not - For Whatever Reason - Learned To Read By The Time You Should.