|Spacecraft Parts: Guidance, Navigation, and Control Systems
The guidance, navigation, and control subsystem is used to control the
orientation (the direction in which it is pointed) of the orbiter as it travels
through space and to maintain knowledge of where celestial bodies are
located (for example, Earth and the sun). This knowledge is critical for
the spacecraft to perform the correct maneuvers to get to Mars, to keep
its solar arrays pointed toward the sun in order to produce power, and
to keep its antenna pointed toward the earth in order to maintain
Once in orbit around Mars, this subsystem will also maintain constant
knowledge of where the spacecraft is in its orbit, and will be able to
point the science cameras very accurately (about 1/20th of one degree).
That ability is critical so that the science instruments can take images of
the necessary targets on the surface.
Together, the guidance, navigation, and control subsystem and
structures subsystems have been designed to provide the smoothest
ride possible. Preventing even tiny vibrations (from, for example,
movement of the solar arrays), is crucial, as the shaking motion could
otherwise cause the science images to become blurred.
To perform its functions, the guidance, navigation and control
subsystem uses several types of:
||for determining where the spacecraft is pointed, how fast it is turning, and how its speed is changing.
||for changing the spacecraft's pointing direction, rate of turning, and speed.