Its attitude in space is maintained by using a star sensor, solar sensors, a magnetometer, gyrometers, several magnetic rods and reaction wheels.
32.
In June 1998 GOES 9 developed a problem with one of its two reaction wheels, which were used to control its orientation.
33.
During the first of these spacewalks, Newman and Massimino replaced an old solar array and a reaction wheel assembly with new units.
34.
Possible additional upgrades include the installation of a new reaction wheel to replace one of the four gyroscope-like devices with faulty electronics.
35.
Then, on May 11, 2013, a second reaction wheel failed, disabling the collection of science data and threatening the continuation of the mission.
36.
After detecting the touchdown, " Philae " reaction wheel was automatically powered off, resulting in its momentum being transferred back into the lander.
37.
The momentum stored in the reaction wheels throughout the orbit was regularly dumped via magnetic coils that interacted with the Earth's magnetic field.
38.
The spacecraft was three-axis stabilized in lunar orbit via reaction wheels with a precision of 0.05 deg in control and 0.03 deg in knowledge.
39.
Observations were halted after one of the spacecraft's four " reaction wheels " experienced problems, causing Cassini to switch to a different maneuvering system.
40.
Combined with reaction wheels, any desired maneuver can be performed as long as the formation s center of mass is not required to change.
