Question: What engines do rockets have????

Jessica Marshall answered on 13 Mar 2014:

A rocket engine is basically a chamber where liquids or gas set on fire. The chamber is enclosed with only a small opening (the nozzle), so when the fire burns, it has to go somewhere and is forced out of the nozzle and produces a force (the thrust). There are different sorts of rocket engines as they can use different sorts of fuel and different amounts of fuel. If you want a really big thrust then you need to use a lot of fuel very quickly; if you want small amounts of thrust but over a longer period of time then you will have to control the engine differently and have a smaller nozzle.