Editing Solid-propellant rocket (section)

==Nozzle==
{{Main|Rocket engine nozzle}}
A [[De Laval nozzle|convergent-divergent]] design accelerates the exhaust gas out of the nozzle to produce thrust. The nozzle must be constructed from a material that can withstand the heat of the combustion gas flow. Often, heat-resistant carbon-based materials are used, such as amorphous [[graphite]] or [[reinforced carbon–carbon]].

Some designs include directional control of the exhaust. This can be accomplished by gimballing the nozzle, as in the Space Shuttle SRBs, by the use of jet vanes in the exhaust as in the [[V-2]] rocket, or by liquid injection thrust vectoring (LITV).

LITV consists of injecting a liquid into the exhaust stream after the nozzle throat. The liquid then vaporizes, and in most cases chemically reacts, adding mass flow to one side of the exhaust stream and thus providing a control moment. For example, the [[Titan III]]C solid boosters injected [[nitrogen tetroxide]] for LITV; the tanks can be seen on the sides of the rocket between the main center stage and the boosters.<ref name="S">{{cite book | author=Sutton, George P. | title=Rocket Propulsion Elements | edition=7th | publisher=Wiley-Interscience | date=2000 | isbn=0-471-32642-9}}</ref>

An early [[LGM-30 Minuteman|Minuteman]] first stage used a single motor with four [[gimbal]]led nozzles to provide pitch, yaw, and roll control.