The NASA Jet Propulsion Laboratory (JPL) team monitoring the Voyager 2 probe had to make a difficult but necessary decision. On September 26, engineers sent a command to the probe to turn off one of its instruments. Objective: To save energy to extend the mission as long as possible.
The signal sent by NASA's Deep Space Network took 38 hours to reach Voyager 2, 20.5 billion kilometers away, and return to Earth.
A tool that played a major role in 2018
The instrument that has just been deactivated is a plasma spectrometer that measures the amount of plasma and the direction in which it flows. In 2018, it played a crucial role in detecting plasma particles falling from the Sun, which helped confirm that Voyager 2 had left the heliosphere and entered interstellar space.
” Mission engineers took steps to avoid shutting down the science instrument for as long as possible, because the science data collected by the twin Voyager probes is unique. “, He explains NASA. “ No other man-made spacecraft has operated in interstellar space, in the region beyond the heliosphere. »
Voyager 1 and 2 are plutonium fueled
The plasma spectrometer was chosen to be turned off due to its lesser role in the follow-up mission. ” It has collected little data in recent years because of its orientation relative to the direction in which plasma flows in interstellar space “, confirms JPL.
Voyager 1 and its twin, Voyager 2, are powered by decaying plutonium and lose about 4 watts of power per year, according to NASA. Voyager 2 took off on August 20, 1977. It had 10 scientific instruments on board. Five of them were phased out between 1989 and 2008 after they completed their studies on the giant planets in the solar system.
The same strategy was applied to Voyager 1, which now only uses four of its instruments, the last to go, the ultraviolet spectrometer in 2016.
Voyager 2 could fly with one scientific instrument at least until the 2030s
JPL engineers also turned off all onboard systems that were not necessary for the probe's operation, including some heaters. An essential power-saving option but recently posed a serious problem when one of Voyager 1's engines had to be restarted.
According to NASA, Voyager 2 has enough energy to continue exploring the region in which it operates with at least one operational science instrument until the 2030s.
