Voyager 1 (and half of its instruments) are back online: sky and telescopes

Things are looking better for one of NASA's longest-running deep space missions. After a period of several months of problems, engineers have announced that the Voyager 1 spacecraft is not only back online but also transmitting useful data from two of the four scientific instruments. Work is currently underway to bring the remaining two instruments into operation.

The problems began last November, when Voyager 1 suddenly started sending out a repeated gibberish signal instead of the science and engineering data it normally sends. Troubleshooting on the 46-year-old spacecraft revealed the culprit: A memory chip in one of the three computers aboard the spacecraft was damaged, perhaps due to the impact of a fast-moving charged particle known as a galactic cosmic ray. The corrupted chip, in turn, prevented communication with one of the probe's subsystems, known as the telemetry modulation unit.

Without the ability to replace the chip, the team focused on a software-based workaround, moving the affected code elsewhere. TO Key Challenge It was finding space to move the code, because no place was big enough to contain the entire affected piece. The team broke the affected code into pieces and relocated them to different positions on the computer, while ensuring that the code could still function as a whole. Additionally, any benchmarks needed to be updated to the affected code.

The first test of this approach was to focus on the spacecraft engineering data code. That modification was made on April 18. traveler 1 It is currently 163 astronomical units from Earth, and it takes 22.5 hours (45 hours round trip) for a signal to reach the spacecraft. Therefore, the team had to wait two days to see if the fix was fixed. When they finally saw that it had worked on April 20, they again had access to the general status of the ship.

Additional upgrades allowed the spacecraft to resume sending scientific data on May 17 from two of its instruments. Voyager 1's magnetometer and plasma wave subsystem have again provided useful data.

Engineers are currently working to bring two other systems back online: the low-energy charged particle instrument and the cosmic ray subsystem. Six other instruments are no longer operational or were turned off after the spacecraft's encounter with Saturn in 1980.

A long mission, almost lost

Voyager 1 has avoided disasters before, albeit of a different kind. After launch on September 5, 1977, an early shutdown of the second stage engine nearly doomed Voyager 1. A longer burn of the Centaur stage barely corrected the situation, with less than four seconds of fuel remaining.

However, it worked, and although Voyager 1 launched after Voyager 2, its more direct trajectory toward the outer solar system meant it reached Jupiter and Saturn first. A close flyby of Titan, Saturn's largest moon, ejected Voyager 1 from the plane of the solar system. towards the constellation Ophiuchus.

With both traveler 1 and traveler 2 Having left the solar system, the goal of its current mission is to explore the interstellar environment beyond the heliospherethe region of space controlled by the Sun's magnetic field. Beyond the arc shock created by the solar wind, the spacecraft can record particles of the interstellar medium.

The Voyager spacecraft also carry a copy of the Golden Record, a time capsule of sorts with sounds and images of Earth for any extraterrestrial saviors who may encounter the spacecraft.

Voyager are two of five spacecraft to escape the solar system, along with New Horizons and Pioneer 10 and 11, which are no longer operational. Also heading outward are the Star-37E/48B upper stage engines for each mission.

With its plutonium fuel now close to half its power, Voyager 1 is expected to continue operating until 2025, and it would be even more surprising to see the mission survive to the half-century mark in 2027. It represents the first steps of the humanity to the galaxy beyond. .