Propulsion How do conventional rockets work?

Why does it take so much energy to launch DS1?

Even though DS1 is much smaller than spacecraft designed to carry humans and many satellites already in orbit, it still takes a lot of thrust to put DS1 into orbit. The reason for this is the gravity of Earth. Earth is a very massive object and pulls strongly on everything close to it. In order to reach escape velocity (the speed needed to push something outside of Earth's gravity well), a huge amount of thrust is needed. That is why large multi-stage rockets, like the Delta II or the Saturn V (the Apollo program's launch rocket), are needed to put something into space.

How did DS1 get into space?
Could NASA use ion propulsion to put a ship into space?
What is gravity?

What is thrust?
How does a multi-stage rocket like the Delta II work?
Why is it a good idea to launch a ship into orbit from near the equator?
What is escape velocity?

What's a gravity well?