Rocket Propulsion Elements, 9th Edition

CHAPTER 18THRUST VECTOR CONTROL

Controlling the flight path and the attitude of a rocket‐propelled vehicle enables it to reach a precise flight destination. Rocket propulsion systems always provide a “push” toward an intended destination, but they also can be made to provide torques that rotate the vehicle in conjunction with the propulsive force. By controlling the direction of thrust vectors through mechanisms described in this chapter, it is possible to influence a vehicle's pitch, yaw, and roll rotations. Thrust vector control units integrated with the principal propulsion system are only effective while it is operating and producing an exhaust jet. For periods of free flight, when the main rocket propulsion system is off, separate propulsion units are needed for achieving control over attitude or flight path. In space, many vehicles utilize dedicated attitude‐control systems with multiple independent thrust‐producing units (see Figs. 1–14 and 4–14). Examples of other dedicated attitude control arrangements are shown in Figs. 3–16, 6–14, 12–27, and 12–28. A related history of flight trajectory control with liquid propellant rocket engines is given in Ref. 18–1.

All chemical propulsion systems may have one of several types of thrust vector control (TVC) mechanisms. Some may apply to solid, hybrid, and liquid propellant rocket propulsion systems, but most are specific to only one of these propulsion categories. In this chapter we describe mechanisms that consist of a single‐nozzle ...