An artist concept depicting one of the twin Voyager spacecraft.

The Voyager team is able to use a set of four backup thrusters, dormant since 1980. They are located on the back side of the spacecraft in this orientation. Credit: NASA/JPL-Caltech

On Tuesday, Nov. 28, 2017, Voyager engineers fired up the four TCM thrusters for the first time in 37 years and tested their ability to orient the spacecraft using 10-millisecond pulses. The team waited eagerly as the test results traveled through space, taking 19 hours and 35 minutes to reach an antenna in Goldstone, California, that is part of NASA’s Deep Space Network.

via Voyager 1 Fires Up Thrusters After 37 Years