In order to conclude 2023, NASA’s Juno mission will make a low pass over Jupiter’s numerous moons, Io.
On December 30, the spacecraft will approach the surface within 930 miles (1,500 kilometers). This week NASA announced that “the pass is expected to allow Juno instruments to generate a firehose of data.”
It will be a lot of fun to beam back that sensor data. A set of radio communication uplinks and downlinks, a radiation-hardened PowerPC processor, 256 MB of flash memory, and 128 MB of DRAM make up the probe’s computer system.
Io is thought to be the most geologically active object in the Solar System. It is somewhat bigger than the moon of Earth. As Jupiter and the other gas giant’s moons pull on Io, its volcanoes spew sulfur plumes that can soar 300 miles (500 kilometers) above the surface.
Several spacecraft have taken pictures of Jupiter and its moons, including Juno. Pioneer 10 and Pioneer 11, which had far more sophisticated imaging systems, arrived first, in 1973 and 1974, respectively. The Voyagers arrived next. The Voyager spacecraft captured images demonstrating plumes rising from Io’s surface, and the Galileo probe arrived in 1995 to join them.
As they sped toward their final destinations, two other spacecraft, Cassini and New Horizons, also made observations.
Currently in the third year of its extended mission to study Jupiter, Juno is scheduled to conduct a second close flyby on February 3, 2024, bringing it within about 930 miles (1,500 kilometers) of the planet. A significant distance less than the 6,830 miles (11,000 km) to 62,100 miles (100,000 km) that the spacecraft had been observing the moon from.
The Stellar Reference Unit is expected to produce the highest-resolution images to date during the flyby, with all three of the spacecraft’s cameras operating. For scientific purposes, this navigation camera has proven to be helpful.
But there are some issues with Juno’s payload. Although JunoCam, which was added for public engagement, will continue to operate, this imager is beginning to deteriorate as it has outlived its anticipated lifespan. After all, its operating range was limited to seven Jupiter orbits. During its Io pass this week, Juno will complete its 57th orbit of Jupiter.
“Over the last few orbits, the cumulative effects of all that radiation have begun to show on JunoCam,” stated Ed Hirst, NASA’s Jet Propulsion Laboratory in Southern California’s Juno project manager.
“Pictures from the last flyby show a reduction in the imager’s dynamic range and the appearance of ‘striping’ noise.”
To minimize the harm and maintain the imager’s functionality, engineers are working hard. 2023 began for the JunoCam with a few technical problems, such as an unusual temperature rise when the device was turned on. Despite the fact that scientists have found the images useful, it is not regarded as one of the science tools.
The Juno team has made a few minor adjustments to the spacecraft’s intended course in order to include additional flybys of Io after February 3. But these will get farther and farther away from the moon; the final one is roughly 71,450 miles (115,000 kilometers) away.
However, everything good has to end. September 2025 is the mission’s end date, unless something goes wrong before then. The information gathered has proven invaluable and will continue to be so for the next Europa Clipper mission and the European Space Agency’s Jupiter Icy Moons Explorer (JUICE), which is scheduled to launch on April 14, 2023, and is expected to reach Jupiter in 2031.
