It's our third morning in space and Mission Control wakes us with more rock music.  Everyone is feeling great.  The one crewmember who had been vomiting is now completely well.  One of the crew floats me a foil pouch of coffee and I sip it while watching the giant satellite I released yesterday.  It's many miles away but the reflecting sunlight has turned it into a morning star brighter than Venus.

Yes, it's a great day.
Then a call comes from Mission Control that changes my mood.

"Atlantis...Houston.  We were wondering if you saw anything break off the top of the right booster during ascent?"
The Commander grabs the microphone.  "Negative, Houston.  Ascent looked nominal.  What's up?"
"In a review of the ground films of your launch, engineers thought they saw something come off the tip of the booster."
I get a sickening feeling in my stomach.  We all do.  If something broke off, it could have hit the belly of the shuttle.  The belly is covered with thousands of very fragile heat tiles.  They're made out of silica, the same stuff that's in sand, and they could be destroyed by an impact.  That doesn't affect us while we're in space.  But on reentry, Atlantis and everything in her, could be turned into ash by the 3000 degrees of air friction.  The heat tiles are the only thing that protects us from burning up.

But what can we do?  How can we see the belly of the shuttle to know if it's damaged?  The NASA team has the answer.

"Atlantis, we want Mike to use the robot arm to look at the belly.  We're transmitting some instructions on how to do that."

Once again the team is depending upon me.  But now I'll be doing something that I haven't practiced.  They want me to bend the robot arm around the side of the shuttle and look underneath.  The TV camera on the end of the arm will transmit pictures of what the belly looks like.
I'll have to be extra careful.  The arm will be bent at a crazy angle.  It will be very close to the shuttle.  One mistake and I could damage the tile for sure.
As I grab the joy sticks and begin the maneuver, I'm scared at what I'll see.  Suppose there's a lot of damage?  There's no way we could repair it.  There's no way to space walk to the belly of the shuttle and, even if we could, we wouldn't have any tools to make a repair.

I shiver in fear as I imagine what would happen to Atlantis if there is major damage.  On reentry, fire would melt a hole in the belly and then start burning through wires and equipment.  Alarms would sound in the cockpit as hydraulic pumps, electrical generators, computers, and other equipment began to fail.  The fire alarm would go off as the heat started a fire in the cockpit.  The other Mission Specialists and I would leave our seats to fight the blaze.  But the reentry g-forces would make me weigh 360 lbs.  My legs would buckle and I would crash to the floor and have to crawl to the fire.  Air would start leaking out and a shrieking hiss would be added to all the other alarms.  To keep us alive, our pressure suits would automatically inflate making the arms and legs as hard as an inflated tire.  We would be like the Tin Man in the Wizard of Oz movie.  We would barely be able to move.