NASA’s Juno spacecraft will take a Cassini-like approach to exploring the Jovian system when it embarks on its latest mission extension in August later this year. Over the next four years the probe will make multiple passes of Jupiter’s rings and moons, and explore key features on the massive planet’s surface including its vast polar vortexes, and the mysterious Great Blue Spot.
Juno was launched in August 2011 with an ambitious mission to peer beneath Jupiter’s roiling cloud surface, in order to reveal hidden characteristics that could help shed light on how the massive planet formed.
To this end, the spacecraft was specially designed to survive the brutal radiation environment surrounding the giant planet. It was also equipped with a suite of advanced scientific instruments, including delicate spectrometers and sensors created to track fluctuations in Jupiter's gravity and magnetic field.
On July 4, 2016, after enduring a 1.7 billion-mile, five-year journey through the hostile environment of interplanetary space, Juno arrived at Jupiter, and proceeded to spend the next four and a half years probing its secrets. During this time it revolutionized our understanding of Jupiter, revealing key insights regarding the internal structure of the gas giant and shedding light on the complex processes occurring in the planet’s magnetic field and atmosphere.
Despite having been active in the radiation-saturated environment for over four years, the hardy spacecraft is still in excellent health, and is currently suffering no significant hardware issues.
On January 8, following an external review conducted by a panel of experts, NASA decided to grant the veteran probe a four-year mission extension with which to further explore the Jovian system. This new mission phase will stretch from August 2021 to September 2025, during which time – if all goes to plan – Juno will complete a further 42 orbits of the gas giant.
A new NASA press release recently highlighted some of the key scientific opportunities stretching ahead of the Juno spacecraft, which will now take on a more all-encompassing, Cassini-like approach to the exploration of the Jovian system.
Over the next four years, the hardy probe will undertake two close-proximity flybys of Ganymede, three of icy Europa, and 11 of Io – one of the most volcanically active worlds in the solar system. Before, during and after these passes, the probe will also take detailed readings on the radiation environment surrounding the gravitationally bound satellites.
The first of the close-proximity passes will take place between Juno and Ganymede on June 7 this year. It is expected that the moon’s gravitational influence will alter the trajectory and speed of the spacecraft, shortening its orbital period from 53 to 43 days.
This gravitational manipulation will also put it on target for a subsequent September 29 rendezvous with Europa, which will further shorten Juno’s orbital period to 38 Earth days. Interactions with Jupiter’s natural satellites will continue to shape Juno’s orbit throughout the remainder of its mission, opening up new scientific opportunities in the process.
Data collected on the moons will help inform the planning of the next generation of moon-exploring missions that are currently in development, including ESA’s Jupiter Icy moons explorer mission (JUICE) and NASA’s upcoming Europa Clipper.
Juno will also carry out an extensive study of Jupiter’s faint rings and its surface features, including the vast cyclones raging at the gas giant’s north pole, and the Great Blue Spot – an isolated region near the equator that boasts strong magnetic field properties.
As it progresses through its mission extension, Juno will continue to examine Jupiter’s structure, atmosphere, magnetosphere and magnetic field, building on the treasure trove of data already collected and transmitted back to Earth via the Deep Space Network.
"Since its first orbit in 2016, Juno has delivered one revelation after another about the inner workings of this massive gas giant," said principal investigator of the Juno mission, Dr. Scott Bolton of the Southwest Research Institute in San Antonio. "With the extended mission, we will answer fundamental questions that arose during Juno’s prime mission while reaching beyond the planet to explore Jupiter’s ring system and Galilean satellites."
Source: NASA
