How does propulsion work?

What is attitude control?

No, attitude is not the way that the spaceship feels about its mission. When NASA scientists or engineers talk about attitude, they mean the way that the ship is positioned in 3-dimensional space. Attitude is in effect, the way that the ship is "pointed."

In order for the ship to go in the right direction, attitude must be monitored and controlled. If even a tiny mistake in the way the ship is pointed isn't corrected, the ship can end up millions of miles off course. Attitude is controlled by tiny thrusters that contain compressed gasses, called monopropellants. These tiny thrusters can be pointed in different directions. Firing those thrusters releases gas which makes the small adjustments needed to get the ship back on course.

What is a propellant?
Do small errors in space navigation matter?

What is thrust?
What kind of fuel is used by DS1's attitude thrusters, and how much of it do they use?
How does DS1 do a course correction?

What is a monopropellant?