What method are employed to determine a spacecraft orientation with respect to a known orientation or plane?
Are gyroscopes reliable enough to make this determination, for example in Voyager spacecraft.
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It only takes a minute to sign up.Sign up to join this community
Just as with aircraft, satellites use a hierarchy of equipment to determine their position and orientation. Satellites typically use accelerometers and gyros for attitude tracking using dead reckoning as a first approximation. These are typically backed up by star trackers (for determining orientation) and radio ranging (for determining location and speed).
Most satellites, at least that I know about, use a series (usually three) of small star tracking telescopes. They are oriented in different directions and locate and lock on to known bright stars. Given the angles to the stars relative to the spacecraft body, the spacecraft knows its orientation in space.
They still use gyroscopes on spacecraft, but as both Wedge and dagorym mentioned, star trackers are used for determining the precise orientation for determining location and orientation so the data can be properly registered.