Surveyor's main rocket engine nozzle sits outside the propulsion module on the end opposite the equipment module. When fired during major maneuvers, this engine will provide a thrust of 659 Newtons. If applied at sea level, that amount of force would be strong enough to suspend a 148 pound person in mid-air.
The main engine derives its power by burning a combination of nitrogen tetroxide (N2O4) and hydrazine (a derivative of N2H4). Engineers working on the project call this chemical combination "hypergolic." This term refers to the fact that the two chemicals will spontaneously combust when they come into contact with each other. In other words, no spark is needed to ignite the engine.
In addition to the main engine, Surveyor also carries small "attitude-control" thrusters attached to each corner of the propulsion module. Each one of these tiny rocket engines will only provide 4.45 Newtons of thrust. Their main purpose involves performing small course correction changes and keeping the spacecraft from wobbling out of control during main-engine burns. In total, Surveyor will carry 385 kilograms (849 pounds) of propellant. Nearly 75% of that amount will be expended during the MOI burn to allow the spacecraft to slow down and enter orbit around Mars.