It turns out NASA’s Juno spacecraft won’t be going anywhere near Jupiter anymore with the space agency revealing that the mission will now remain in the current 53-day orbit for the remainder of the mission.
On an optimistic note NASA says that Juno will be able to accomplish all its science goals even after remaining in this longer orbit and would also allow the mission team to go for ‘bonus’ science activities that weren’t originally planned for the mission.
As per the original plan, the Juno spacecraft was meant to perform only two orbits of Jupiter at the current 53-day orbit and post the two orbits, the mission team was to lower it to an orbit that would have taken the spacecraft into a 14-day orbit. However, things didn’t go as planned and according to the mission team, two helium check valves that are part of the plumbing for the spacecraft’s main engine did not operate as expected when the propulsion system was pressurized in October. Telemetry from the spacecraft indicated that it took several minutes for the valves to open, while it took only a few seconds during past main engine firings.
Post a series of simulations that involved scenarios that would have put Juno in a shorter-period orbit, the mission team decided against going for another main engine burn as it could result in a less-than-desirable orbit. The mission team concluded that a main engine burn represents a risk to completion of Juno’s science objectives and that’s a risk that can’t be taken.
Juno is operating well and is sending in data and images that are revealing some amazing things about the largest planet in our Solar System. Juno has successfully orbited Jupiter four times since arriving at the giant planet, with the most recent orbit completed on Feb. 2. Its next close flyby of Jupiter will be March 27.
NASA has said that the current orbit will not have a detrimental effect on the quality of science that Juno is to perform throughout its life and in fact, the longer orbit provides new opportunities that allow further exploration of the far reaches of space dominated by Jupiter’s magnetic field, increasing the value of Juno’s research.
During each orbit, Juno soars low over Jupiter’s cloud tops – as close as about 2,600 miles (4,100 kilometers). During these flybys, Juno probes beneath the obscuring cloud cover and studies Jupiter’s auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.
Juno’s larger 53-day orbit allows for “bonus science” that wasn’t part of the original mission design. Juno will further explore the far reaches of the Jovian magnetosphere – the region of space dominated by Jupiter’s magnetic field – including the far magnetotail, the southern magnetosphere, and the magnetospheric boundary region called the magnetopause. Understanding magnetospheres and how they interact with the solar wind are key science goals of NASA’s Heliophysics Science Division.
Juno will continue to operate within the current budget plan through July 2018, for a total of 12 science orbits. The team can then propose to extend the mission during the next science review cycle. The review process evaluates proposed mission extensions on the merit and value of previous and anticipated science returns.