AUTHOR'S NOTES

What did we find when we walked around Atlantis and looked at her belly?  Over 700 heat tiles had been damaged so badly that they would later have to be replaced.  Only one tile was completely missing, but the others around it had protected Atlantis' aluminum skin from melting.  We had been very lucky.
What had caused all this damage?  In the factory, the very tip of the right-side rocket booster had been made too weak.  The wind pressure during launch had broken it off and it had hit the belly.  To make certain it could not happen on another mission, NASA changed the way the boosters were built to make them stronger.
ON BEING AN ASTRONAUT
There are two types of NASA astronauts: Pilot Astronauts and Mission Specialist Astronauts.  Pilot Astronauts sit in the front seats and have the controls and instruments to fly the shuttle during launch and landing.  The Pilot Astronaut that sits in the front-left seat is also called the Commander.  He/she is the overall boss.  The Pilot Astronaut who sits in the front-right seat is called the Pilot and helps the Commander to fly the spaceship.  He/she is really like a copilot in a regular airplane.  Mission Specialist Astronauts (called MS's) are the crewmembers (usually three) who do most of the work once the shuttle reaches orbit.  They operate the robot arm, do experiments, do spacewalks and release satellites.
What kind of an education do you need if you want to be an astronaut?  NASA requires that all astronauts have a college degree in math, science or engineering.  You can't be an astronaut if you get a degree in things like english, history, music, physical education, law, etc.  NASA says you only need a Bachelor's degree to be eligible for an astronaut job but almost everybody they choose has at least a Master's degree.  Ask your teacher to explain Bachelor, Master's, and Doctorate degrees. Do you have to be a pilot or be in the military to be an astronaut?  No.  About one-third of the astronauts are civilians who are not pilots.  But if you're not a pilot you can only apply for the Mission Specialist Astronaut position.
To be a Pilot Astronaut, NASA requires that you have at least 1000 hours of jet flying time.  For this reason all Pilot Astronauts are military flyers.  You should plan on being a military test pilot if you want to be a Pilot Astronaut.
THE SPACE TRANSPORTATION SYSTEM (STS)
The mission of the space shuttle, or STS as NASA calls it, is to carry satellites and experiments into orbits about 150 to 350 miles above the earth.  While it can't fly to the moon (that's about 240,000 miles away), the shuttle can do something no rocket before it could ever do.  It can be recycled.  Before the shuttle, all of our rockets, including the moon rockets, were "throw-away" rockets.  In other words, during their missions all of their parts were jettisoned to fall into the water or burn up in the atmosphere.  The only thing that ever came back was the capsule with the astronauts in it.  Even that was never used again.  It was sent to a museum.  But almost all of the STS can be used over, which saves money.
There are three parts to the STS:  The Orbiter is the winged vehicle that carries the astronauts.  Five Orbiters have been built: Columbia, Challenger, Discovery, Atlantis, and Endeavour.  The Orbiter Challenger was destroyed and her astronauts were killed on January 28, 1986 when a hole burned through the side of one of the solid-fueled rocket boosters.
The External Tank (ET) is the giant, orange-colored fuel tank that's attached to the belly of the Orbiter.  The ET is the only part of the STS that's not reused.  It's jettisoned into the ocean.
The Solid-fueled Rocket Boosters (SRB's) are the giant, white booster rockets that are attached to each side of the ET.  When they burn out, they are jettisoned and parachute into the ocean.  Tug boats pick them up and tow them to shore so they can be cleaned, refilled with more solid fuel and used over again. 

THE FUTURE
The STS, the shuttle, is not the end of America's space program.  It's just a step, like the Mercury, Gemini, Apollo, and Skylab space projects before it.  Soon, if our Congress gives NASA the money, the next step will be taken.  We will work with the Russians, Japanese, Canadians and Europeans to assemble a space station about 300 miles above the earth.  We need such a station so astronauts can live and work in space for very long periods.  While the shuttle may be recyclable, it can only stay in orbit for about two weeks before it runs out of electricity.  That's not enough time to complete many experiments.  If we could stay in orbit for years on a space station, we might be able to make new medicines, metals, computer chips, and many other things that will help us have better lives on earth. After the space station, NASA plans to return to the moon.  Astronauts would build a permanent moon base with telescopes and other instruments to help us better understand our universe. Then, NASA wants to send men and women to the planet Mars.  Who will be the first humans to step foot on the red planet?  Could it be you?  A mission to Mars could begin in as little as 30 years.  The astronauts who take that trip will be about 40 to 45 years old.  That means they are now children between 10 and 15 years old.  That's your age!  That means YOU could be the first Martian!  Imagine that incredible journey...