Voyager 2 Completes Power Saving Switch to Backup Thruster Set

In an ongoing effort to extend the life of the Voyager's mission engineers continue to switch off power consuming devices. In this case switching to the backup roll control thrusters allows the heaters on the primary set to be switched off to conserve power. Power conservation is necessary because the craft's nuclear generator's degrade over time.

It is absolutely amazing that these 34 year old spacecraft are still functioning.  It's a true testament to the genius of the engineers who designed and built them.

Voyager 2 Completes Switch to Backup Thruster Set - NASA Jet Propulsion Laboratory: "NASA's Voyager 2 has successfully switched to the backup set of thrusters that controls the roll of the spacecraft. Deep Space Network personnel sent commands to the spacecraft to make the change on Nov. 4 and received confirmation today that the switch has been made. 

Voyager 1 and Voyager 2 are each equipped with six sets, or pairs, of thrusters to control the pitch, yaw and roll motions of the spacecraft. These include three pairs of primary thrusters and three backup, or redundant, pairs. Both spacecraft are now using all three sets of their backup thrusters."