August 13, 2022

Engineers consult 45-year-old Voyager manuals to fix a bug

Engineers consult 45-year-old Voyager manuals to fix a bug

In May, NASA scientists said the Voyager 1 spacecraft was sending inaccurate data from it Height control system. The mysterious glitch still persists, according to the mission’s engineering team. Now, in order to find a solution, engineers are searching decades-old clues.

Voyager 1, along with the twin Voyager 2, was launched in 1977 with a design life of five years To study Jupiter, Saturn, Uranus, Neptune and its moons closely.

After nearly 45 years in space, both spacecraft are still in service. In 2012, Voyager 1 became the first man-made object to emerge outside the limits of the Sun’s influence, known as the heliosphere, and into interstellar space. He’s around now 14.5 billion miles from Earth and sending data from outside the solar system.

“No one thought it would last as long,” Susan Dodd, the Voyager mission project manager at NASA’s Jet Propulsion Laboratory, told Insider. “And here we are.”

Voyager 1 was designed and built in the early 1970s, which complicated efforts to troubleshoot spacecraft problems.

Although current Voyager engineers have had some documents — or command media, the technical term for paperwork containing details about spacecraft design and procedures — since the early mission days, other important documents may have been lost or misplaced.

An engineer works on the vibration acoustics and thermal shocks of one of NASA's Voyager spacecraft on November 18, 1976.

An engineer works on an instrument for one of NASA’s Voyager spacecraft, on November 18, 1976.

NASA/JPL-Caltech


During the first 12 years of the Voyager mission, thousands of engineers worked on the project, according to Dodd. “When they retired in the ’70s and ’80s, there wasn’t much motivation to own a project document library,” Dodd added. “People were taking their boxes to their garage.” On recent missions, NASA maintains more robust documentation records.

There are some boxes with documents and charts stored off-site from JPL, and Dodd and the rest of the Voyager wizards can request access to these records. Still, it can be a challenge. “Having this information requires you to know who is working in that area of ​​the project,” Dodd said.

For the latest Voyager 1 glitch, mission engineers had to specifically search for boxes under the name of the engineers who helped design the altitude control system. “It’s a time-consuming process,” Dodd said.

The spacecraft’s altitude control system, which sends telemetry data to NASA, indicates the direction of Voyager 1 in space and keeps the spacecraft’s high-gain antenna pointed at Earth, enabling it to send the data home.

“Telemetry data is basically a case of system health,” Dodd said. But the telemetry readings that spacecraft operators get from the system are distorted, according to Dodd, meaning they don’t know if the altitude control system is working properly.

This archive photo shows an engineer building a large, high-gain Voyager dish antenna.  The photo was taken on July 9, 1976.

An engineer builds a large, high-gain Voyager dish-shaped antenna, on July 9, 1976.

NASA/JPL-Caltech


So far, Dodd said, Voyager engineers haven’t been able to find a root cause for the malfunction, mainly because they haven’t been able to reset the system. Dodd and her team believe this is due to the aging of a part. “Not everything works forever, even in space,” she said.

The Voyager glitch may also be affected by its location in interstellar space. According to Dodd, spacecraft data indicate that high-energy charged particles are present in interstellar space. “It’s unlikely that one of them would hit the spacecraft, but if it did, it could cause more damage to the electronics,” Dodd said, adding, “We can’t pinpoint that as the source of the anomaly, but it could be a factor.”

Despite the spacecraft’s orientation issues, it still receives and carries out commands from Earth and its antenna is still pointed toward us. “We haven’t seen any deterioration in signal strength,” Dodd said.

as part of Continuous power management voltage That has escalated in recent years, engineers have been turning off the non-technical systems aboard Voyager’s sensors, such as the heaters of its science instruments, hoping to keep them going into 2030.

Saturn as seen by Voyager 1 when it looked back on November 16, 1980, four days after the spacecraft flew over the planet.

Voyager 1 looked at Saturn on November 16, 1980, to give this unique perspective on its rings.

NASA/JPL


From the discovery of unknown moons and rings to the first direct evidence of the heliosphere, Voyager mission Help scientists understand the universe. “We want the mission to last as long as possible, because the scientific data is so valuable,” Dodd said.

“It’s really remarkable that both vehicles are still up and running well — some glitches, but they’re both doing very well and still sending such valuable data,” Dodd said.