Don’t let gravity get you down

How inertia and gravity work on the space shuttle:

Gravity tries to pull the space shuttle towards the earth,  the shuttle moves forward in a straight line because of inertia..

I am going to describe this process with the following example:

Imagine a little league baseball player hitting a home run.  The ball flies
out caused by the force of the bat (inertia) but it is brought to earth by
gravity and slowed down in its flight by friction with the air.

Further, imagine Derek Jeter hitting a home run.  The ball travels farther
and higher (more inertia) but it is still slowed by friction and pulled down
by gravity.  It just takes longer for these things to happen because Derek
Jeter provided more initial force than the little leaguer.

Now imagine one step further.  The ball was hit with enough force to so that
its falling path matches the curvature of the earth.  Since friction is
almost nonexistent outside our atmosphere, there is very little to slow it
down, the ball is able to maintain its speed and goes into orbit around the
earth.  This is called “free fall” and you probably have experienced it while
going downhill on a roller coaster.  It is that feeling when we seem to come
off of our seat and our stomach seems to rise.  Did you ever notice that
“floating” feeling when going down that hill?