Re: Could you explain the satellite launch process and orbital insertion?

I'm not sure exactly what you are looking for here, but I will give you a few facts and figures and 
some links for you to find out more.

There is no required weight to be in orbit around the Earth (or any planet, asteroid, etc.).  You 
simply must obtain enough forward velocity so that as you are moving forward, the Earth surface 
is curving away from you at the same rate at which you are "falling toward it"  So for "Low Earth 
Orbit," which is the orbit that the Space Shuttle and the Space Station are in, this speed is about 
17,500 miles per hour (about 28,000 km/h).  It does not matter how much mass an object has - 
a mouse or the whole Space Station itself.  They are all in orbit traveling 17,500 mph.

With current technology, the best way to achieve these kinds of speeds is by using rockets.  And 
even so, it takes a lot of fuel to get going that fast - in fact, most of the mass of a rocket (90+%) 
is the fuel.   So, as you can imagine, if you could get a boost from some other means, it would be 
a great benefit.  This is where the location of the launch site on the Earth comes into play.

The earth is rotating on its axis (which is why we have day and night) at one revolution every 24 
hours.  This means that relative to the center of the Earth, a person on the surface at the equator 
is moving about 1000 mph.  The farther away from the equator you are, the slower you are 
moving relative to the center of the Earth (at the north or south poles, it is zero).  If you launch a 
rocket in the same direction the Earth is rotating, you start out already moving at 1000 mph!  For 
this reason, it is desirable to have launch sites as close to the Equator as possible.  And it is also 
why (almost) all rockets launch to the East.

A friendly text explaining how this works for the Space Shuttle can be found here:
 http://spaceflight.nasa.gov/

Specifically,
 http://
spaceflight.nasa.gov/shuttle/reference/basics/index.html


A good source for some orbital mechanics basics is another NASA site:
 http://
liftoff.msfc.nasa.gov/academy/rocket_sci/orbmech/orbmech.html

I hope this was useful.  To get more info I would do a Google search for "Orbital mechanics" or 
"spaceflight basics"

-Steve