Question: how much thrust does a spacecarft engine produce on average

Christopher Youens answered on 4 Mar 2019:

This depends on the spacecraft and the purpose of the engine. On the satellites I take care of, they use a small engine that only produces 0.02N of thrust! But that’s plenty for us just to maintain our orbit over seven years.

The more important value is the ‘specific impulse’ of the engine, that tells us how fast the exhaust velocity is. The higher that value, the more efficient our engine is, and that means less fuel and less mass to get into orbit!