It has two radio systems as well as a sun sensor and gyroscopes to orient it in space.

Today's events were in sharp contrast to Wednesday's trouble, when a sun sensor detected a bright light and moved the satellite into the wrong position.

A sun sensor is a device that senses the direction to the Sun.

The spacecraft was three-axis stabilised, with sun sensors used to maintain a constant attitude with respect to the Sun.

Cruise avionics systems allow the flight computer to interface with other electronics, such as the sun sensors, star scanner and heaters.

Though problems with the onboard sun sensor forced cancellation of the first exhaust plume observation, other observations went well later in the day.

The sensor array that determines attitude is made up of a magnetometer and a sun sensor.

The sun sensors are planar photo diodes that detect the intensity of incoming sunlight.

The only problem occurred a few days after launch, when one of the sun sensors produced occasional false readings and shut down the satellite.

Engineers were studying data from Pathfinder's sun sensor, which helps the spacecraft orient itself.