Editing Rocket engine (section)

===Injection===
[[Liquid-propellant rocket|Liquid-fueled rockets]] force separate fuel and oxidizer components into the combustion chamber, where they mix and burn. [[Hybrid rocket]] engines use a combination of solid and liquid or gaseous propellants. Both liquid and hybrid rockets use ''[[Liquid-fuel rocket#Injectors|injectors]]'' to introduce the propellant into the chamber. These are often an array of simple [[jet (nozzle)|jet]]s – holes through which the propellant escapes under pressure; but sometimes may be more complex spray nozzles. When two or more propellants are injected, the jets usually deliberately cause the propellants to collide as this breaks up the flow into smaller droplets that burn more easily.