How do they point a camera on a space probe?

Question

When a probe like Voyager 1 is sent into deep space they are able to point the camera at the planet and its moons and take pictures.

• How is the camera pointed at the object?
• Is the camera fixed to the probe or do motors orient the camera independently?
• Do they know the exact position of the probe with respect to the planet and pre-program orientations and exact times to take pictures?
• Is there something on board to point the camera at a close gravitational mass of some kind?
• Some other sensor to orient the probe? Light or infrared? How do they make sure it doesn't get confused by the sun?

Answer 1

1) Motors orient the camera independently of the satellite. The satellite has to be oriented so its big dish antenna is pointed toward Earth.

2) Yes they know the position, and they pre-program the photographs, because instructions take hours to get there.

3) is there a gravitational sensor? Not for pointing cameras.

4) For orientation, they have inertial (gyroscope) sensors and visual trackers of known stars, like Canopus.

Check out Voyager Spacecraft.