Lost Twin found: NASA's Voyager 2 fixed from 11.5 billion miles

Voyager 2

Mission operators reported that Voyager 2 spacecraft resumed its exploration of interstellar space earlier this week. The engineers fixed a potentially fatal glitch from 11.5 billion miles away. The health of the instruments is being further evaluated as Voyager 2 continues to be stable and is in contact with NASA’s Jet Propulsion Laboratory in California.

Crux of the Matter

Voyager 2’s Purpose
It was built in motion to accompany its twin in transforming our understanding of our stellar neighbourhood, by revealing unprecedented information about the interstellar space, beyond the Sun’s sphere of influence. Multiple fault protection routines were programmed in both, in order to allow them to automatically take actions to protect themselves if potentially harmful circumstances arose.

What Had Happened?
Launched in 1977, Voyager 1 and Voyager 2 both were the most distant human-made objects to be launched in the solar system. On Jan. 25 2020, Voyager 2 ran into trouble when it didn’t execute a scheduled manoeuvre in which the spacecraft rotates 360 degrees in order to calibrate its onboard magnetic field instrument. Analysis of the telemetry from the spacecraft indicated that an unexplained delay in the onboard execution had occurred. This caused the Voyager 2 to overdraw its available power supply.

Challenges Ahead
The Voyager’s power supply comes from a radioisotope thermoelectric generator (RTG), which turns heat from the decay of radioactive material into electricity to power the spacecraft. Thus the science team has to manage both the power supply and the temperature of certain systems on the spacecraft. Communications traveling at the speed of light take about 17 hours to reach the spacecraft, and it takes another 17 hours for a response from the spacecraft to return to Earth. As a result, mission engineers have to wait about 34 hours to find out if their commands have had the desired effect on the spacecraft.


Voyager 2 is a space probe launched by NASA on August 20, 1977, to study the outer planets. Part of the Voyager program, it was launched 16 days before its twin, Voyager 1, on a trajectory that took longer to reach Jupiter and Saturn but enabled further encounters with Uranus and Neptune. It is the only spacecraft to have visited either of these two ice giant planets. Constructed by the Jet Propulsion Laboratory (JPL), Voyager 2 includes 16 hydrazine thrusters, three-axis stabilization, gyroscopes and celestial referencing instruments (Sun sensor/Canopus Star Tracker) to maintain pointing of the high-gain antenna toward Earth. It is the fourth of five spacecraft to achieve the Solar escape velocity, which will allow it to leave the Solar System. Currently, it has begun to provide the first direct measurements of the density and temperature of the interstellar plasma. More Info