Juno blocked in an elliptical orbit around Jupiter


Following a motor problem, the Juno sensor will not perform the orbital reduction maneuver initially planned but the mission is not compromised.

Since July 5, 2016, the Juno probe has arrived near Jupiter and has begun its mission of scientific investigation, scheduled to last until February 2018.

The probe was to perform 36 complete orbits around the giant planet. In order to successfully complete the program, it would have had to leave its very elliptical orbit in October 2016, which led it to circle Jupiter in 53.4 days to position itself on a more circular trajectory reducing the time to only 14 days.

The operation requires the ignition of the main Leros engine, which has not been used since the insertion in July 2016. But during preparatory tests, NASA found that two valves in the engine pressurization system were malfunctioning.

After unsuccessfully trying to solve this problem, NASA engineers finally decided not to take risks and leave Juno in its long orbit. This choice does not obliterate the scientific objectives of Juno which in both configurations approaches Jupiter at the same distance.

The JunoCam observations and recordings are therefore of interest. And this mishap could even favor new studies: by remaining in its elliptical orbit, the probe will be able to observe the confines of the Jovian magnetosphere. And it will also remain less time in the areas of strong radiation that surround the Giant, which should extend its lifetime.

The mission time could therefore be extended by a few weeks after February 2018. It is still expected that the adventure of Juno will end with a scheduled collision on Jupiter.