NASA engineers recently made a tough decision to turn off the plasma science instrument on the Voyager 2 spacecraft. This spacecraft has been traveling through space since it launched on Aug. 20, 1977. It is now an incredible 12.8 billion miles (20.5 billion kilometers) away from Earth!
The shutdown of this instrument is due to the spacecraft's dwindling power as it continues its journey into interstellar space, which is the area beyond our solar system.
Voyager 2's Role in Interstellar Research
Voyager 2 was sent out to explore the outer planets and learn more about the heliosphere, the protective bubble around our solar system created by the sun. It left the solar system on Nov. 5, 2018, and it became the only spacecraft actively studying interstellar space, according to Space.com.
Voyager 2 has four scientific instruments on board, which help it study the solar wind and plasma beyond the heliosphere. However, as the spacecraft gets older, it is using up its energy, forcing the engineers to decide which instruments can stay on and which need to be turned off.
NASA thinks Voyager 2 can keep at least one scientific instrument running into the 2030s, but they must carefully pick which instruments to turn off. So far, they have already shut down six of the ten original instruments to save energy.
The plasma science instrument, which measures the amount and direction of plasma (a fluid made of charged particles), was the latest to be switched off on Sept. 26.
The plasma science instrument has four "cups." Three of these cups face the sun and measure solar wind, which is made of particles from the sun. The fourth cup looks at plasma in magnetic fields and in the vast area of interstellar space.
This instrument was important because it helped confirm that Voyager 2 had exited the heliosphere in 2018 when scientists noticed fewer particles coming from the sun.
NASA's Commitment to Voyager 2
NASA's Jet Propulsion Laboratory, which is in charge of the Voyager mission, is very focused on keeping the spacecraft healthy, according to Phys.org. The mission team has been working hard to delay turning off any instruments since the data from Voyager 2 is very important. It is the only spacecraft gathering information in interstellar space.
However, the plasma science instrument's ability to gather data had become limited. When Voyager 2 moved beyond the heliosphere, the three cups aimed at the sun could no longer collect useful data, making the instrument less effective. While the fourth cup still provided some readings, it could only do so every three months. This led the engineers to decide to turn off the instrument before others.
The Voyager 2 spacecraft uses a type of power source that slowly runs out. It loses about four watts of power every year. After the spacecraft studied the giant planets in the 1980s, the team turned off many instruments that were no longer needed to keep the mission going. Recently, they have also turned off other systems to conserve energy.
