An experimental method rescued a digicam aboard the company’s Juno spacecraft, providing classes that can profit different house methods that have excessive radiation.
The mission group of NASA’s Jupiter-orbiting Juno spacecraft executed a deep-space transfer in December 2023 to restore its JunoCam imager to seize photographs of the Jovian moon Io. Outcomes from the long-distance save have been offered throughout a technical session on July 16 on the Institute of Electrical and Electronics Engineers Nuclear & Area Radiation Results Convention in Nashville.
JunoCam is a colour, visible-light digicam. The optical unit for the digicam is positioned exterior a titanium-walled radiation vault, which protects delicate digital parts for a lot of of Juno’s engineering and science devices.
It is a difficult location as a result of Juno’s travels carry it by means of probably the most intense planetary radiation fields within the photo voltaic system. Whereas mission designers have been assured JunoCam might function by means of the primary eight orbits of Jupiter, nobody knew how lengthy the instrument would final after that.
All through Juno’s first 34 orbits (its prime mission), JunoCam operated usually, returning photographs the group routinely integrated into the mission’s science papers. Then, throughout its forty seventh orbit, the imager started exhibiting hints of radiation injury. By orbit 56, almost all the pictures have been corrupted.
Whereas the group knew the difficulty could also be tied to radiation, pinpointing what, particularly, was broken inside JunoCam was troublesome from a whole bunch of thousands and thousands of miles away. Clues pointed to a broken voltage regulator that’s important to JunoCam’s energy provide. With few choices for restoration, the group turned to a course of referred to as annealing, the place a cloth is heated for a specified interval earlier than slowly cooling. Though the method will not be nicely understood, the thought is that the heating can scale back defects within the materials.
“We knew annealing can typically alter a cloth like silicon at a microscopic stage however didn’t know if this might repair the injury,” mentioned JunoCam imaging engineer Jacob Schaffner of Malin Area Science Methods in San Diego, which designed and developed JunoCam and is a part of the group that operates it. “We commanded JunoCam’s one heater to lift the digicam’s temperature to 77 levels Fahrenheit — a lot hotter than typical for JunoCam — and waited with bated breath to see the outcomes.”
Quickly after the annealing course of completed, JunoCam started cranking out crisp photographs for the following a number of orbits. However Juno was flying deeper and deeper into the guts of Jupiter’s radiation fields with every cross. By orbit 55, the imagery had once more begun exhibiting issues.
“After orbit 55, our photographs have been filled with streaks and noise,” mentioned JunoCam instrument lead Michael Ravine of Malin Area Science Methods. “We tried totally different schemes for processing the pictures to enhance the standard, however nothing labored. With the shut encounter of Io bearing down on us in a couple of weeks, it was Hail Mary time: The one factor left we hadn’t tried was to crank JunoCam’s heater all the way in which up and see if extra excessive annealing would save us.”
Take a look at photographs despatched again to Earth through the annealing confirmed little enchancment the primary week. Then, with the shut strategy of Io solely days away, the pictures started to enhance dramatically. By the point Juno got here inside 930 miles (1,500 kilometers) of the volcanic moon’s floor on Dec. 30, 2023, the pictures have been nearly pretty much as good because the day the digicam launched, capturing detailed views of Io’s north polar region that exposed mountain blocks lined in sulfur dioxide frosts rising sharply from the plains and beforehand uncharted volcanos with intensive stream fields of lava.
Up to now, the solar-powered spacecraft has orbited Jupiter 74 occasions. Not too long ago, the picture noise returned throughout Juno’s 74th orbit.
Since first experimenting with JunoCam, the Juno group has utilized derivations of this annealing method on a number of Juno devices and engineering subsystems.
“Juno is instructing us the best way to create and keep spacecraft tolerant to radiation, offering insights that can profit satellites in orbit round Earth,” mentioned Scott Bolton, Juno’s principal investigator from the Southwest Analysis Institute in San Antonio. “I anticipate the teachings realized from Juno will likely be relevant to each protection and business satellites in addition to different NASA missions.”
NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Analysis Institute in San Antonio. Juno is a part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Area Flight Heart in Huntsville, Alabama, for the company’s Science Mission Directorate in Washington. The Italian Area Company, Agenzia Spaziale Italiana, funded the Jovian InfraRed Auroral Mapper. Lockheed Martin Area in Denver constructed and operates the spacecraft. Numerous different establishments across the U.S. offered a number of of the opposite scientific devices on Juno.
Extra details about Juno is at:
DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
Deb Schmid
Southwest Analysis Institute, San Antonio
210-522-2254
dschmid@swri.org
2025-091