In light of engine troubles, NASA scientists have determined Juno should remain in its current 53-day orbit around Jupiter. Juno was originally supposed to perform a series of adjustments to its course, and settle into 14-day science orbits that made increasingly deep dives crosswise through Jupiter's magnetic field. But a stuck helium check valve changed Mission Control's collective mind. They're no longer confident Juno will be able to pull off its remaining orbital maneuvers, so they're taking a conservative approach to further navigation.
Juno's complement of scientific instrumentation. Its magnetometer and its JEDI and JADE instruments will help us understand what's inside Jupiter. Image: NASA
"During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit," said(Opens in a new window) Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory. "The bottom line is a burn represented a risk to completion of Juno's science objectives."
NASA is very much putting a positive spin on this development. Juno's wider 53-day orbit allows for what NASA officials are calling "bonus science" that wasn't included in the original mission design. Instead of exploring the inner regions of the magnetosphere, officials said, Juno will explore the farther reaches of the Jovian magnetosphere, which is the region of space dominated by Jupiter's magnetic field. Juno will continue to operate through July 2018, completing a total of 12 science orbits. The team can then propose to extend the mission during the next science review cycle.
This was the original mission plan for Juno. Now, instead of making all those close little science orbits, Juno will be restricted to its 53-day orbit. Image: NASA/JPL
Juno will also spend less time within the dangerous radiation belts on each orbit, according to Juno's principal investigator Scott Bolton, from the SwRI. Radiation hardening was one of the main mission considerations when building Juno, as Jupiter's ludicrous magnetic field is enough to fry even the boldest of spacecraft. The orbiter was swaddled in those shiny thermal blankets, which act as a Faraday cage around it. It’s got an extra copy of everything important, because orbiting around Jupiter, mission control had to assume that at some point, some critical part would short out and die. All its cords and cables are clad in braided metallic shields. Even the specifics of its polar orbit were planned to keep it in the easiest-to-handle parts of the magnetosphere, making shallow dips along the direction of the field lines most of the time. Only toward the end was Juno intended to make its most dangerous approaches through the steepest part of the magnetic gradient around Jupiter.
While Juno is in orbit getting its science on, you can check out some visuals of what it's doing thanks to NASA's Eyes On Juno(Opens in a new window) app. Using Eyes on the Solar System and simulated data from the Juno flight team you can ride on-board the spacecraft on your Mac or PC -- in 3D! No word yet on how the app will have to be retooled to handle the new orbital plan, but NASA already puts out a tremendous amount of information about Juno and Jupiter that you can dig right into if you're so inclined.
