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NASA Space Earth Science

Juno Jupiter Probe Won't Move Into Shorter Orbit After All (space.com) 58

NASA announced today that their Juno spacecraft will not move into a closer orbit around Jupiter as originally planned. "Juno slipped into a highly elliptical, 53-Earth-day-long orbit around Jupiter when it arrived at the giant planet on July 4, 2016," reports Space.com. From their report: The probe was supposed to perform an engine burn in October to reduce its orbital period to 14 days, but an issue with two helium valves postponed that maneuver. The engine burn has now been canceled, meaning Juno will stay where it is through the end of its mission. "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," Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement. "The bottom line is, a burn represented a risk to completion of Juno's science objectives." But Juno should still be able to accomplish its mission goals in the longer orbit, NASA officials said. In fact, the 53-day path will allow the probe to perform some "bonus science" in the outer regions of Jupiter's magnetosphere, they added.
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Juno Jupiter Probe Won't Move Into Shorter Orbit After All

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  • by backslashdot ( 95548 ) on Saturday February 18, 2017 @02:16AM (#53890997)

    I hope they didn't permanent cancel it. Once the science objectives are completed, they should attempt this maneuver. Juno doesn't have a good imager, so closer the better. Would have been nice to get some 3D close ups of the clouds.

    • by Tablizer ( 95088 )

      Once the science objectives are completed, they should attempt this maneuver.

      They should attempt an engine burn near the end to try to understand what went wrong to prevent it on another mission. I'm sure they'll orbit and observe until too many instruments or stabilizers fail, but near the edge of usefulness they should probably do engine burn tests.

      • Re:Good idea for now (Score:5, Informative)

        by mrsquid0 ( 1335303 ) on Saturday February 18, 2017 @12:38PM (#53892463) Homepage

        The plan is to crash Juno into Jupiter at the end of the mission, so we will get some nice close-up imagery at the end. This will require a manoeuver to change the orbit. The telemetry from the de-orbit burn may provide some useful information about the valves. The reason to de-orbit Juno into the planet is to be sure the probe does not contaminate any of the Jovian moons at some point in the future. After all, we do not want to (eventually) go to Europa and find e. coli spreading from the crash site.

    • Comment removed based on user account deletion
    • by AC-x ( 735297 )

      The planned end of mission is to crash it in to Jupiter to avoid any possibility of contaminating Europa [wikipedia.org]. If there's any chance this maneuver would cause them to lose control and not be able to deorbit they probably won't attempt it.

    • Helium sabotaged? But you do not **believe** the schizophrenic communal insect is connected and permanently clamped on NO. If they hear (anyone thought) of it (at all), they will want it disabled because: **it is speaking**.
  • by hcs_$reboot ( 1536101 ) on Saturday February 18, 2017 @03:37AM (#53891107)
    Voyagers and the like did way better in 1977.
    • The probes these days do orders of magnitude more science per mission than the Voyagers ever did. And they do it at a much finer grained quality as well.

      • The probes these days do orders of magnitude more science per mission than the Voyagers ever did. And they do it at a much finer grained quality as well.

        Yep, this is the kind of banal reply I predicted the GP would get. Don't you think everybody and their dogs already know what you wrote?

        • You call my reply "banal" and then add fuck all to the discussion. Did you just want to feel important by putting someone down or are you just an every day idiot?

        • this is the kind of banal reply I predicted the GP would get. Don't you think everybody and their dogs already know what you wrote?

          Shooting an anti-science ignoramus like hcs_$reboot in the arse is generally a positive contribution - to humanity in general and Slashdot in particular. Unlike your utterly useless comment.

    • by blind biker ( 1066130 ) on Saturday February 18, 2017 @08:15AM (#53891509) Journal

      I know your post will get a lot of hate, but there's truth to it: Voyager 1 still took the most impressive close-up photographs of Jupiter. Shit like this http://voyager.jpl.nasa.gov/im... [nasa.gov]
      And the images Voyager took of Saturn are pretty epic, too: http://voyager.jpl.nasa.gov/ga... [nasa.gov]

      In their shortsightedness, they will say these aren't of great scientific value. A more sophisticated mind understands that the scientific importance of these images was enormous, because it inspire hundreds, if not thousands, to do science as their calling.

      • It seems kind of silly to insist Voyager is objectively better because it inspired people, as if a copy of Juno in the 70s would have not. People around here like to insist that some minor difference in the technology of space probe images would have made drastic difference in the inspiration ability of the resulting images. The impact of the images have more to do with the times they are published and novelty, than say a wide angle lens at 70,000 km vs narrow angle at 350,000 km, or filter wheel vs. consum

      • by AC-x ( 735297 )

        Voyager 1 still took the most impressive close-up photographs of Jupiter

        What about the Cassini photos? It took amazing images of Jupiter [universetoday.com] and Saturn [nasa.gov].

        In their shortsightedness, they will say these aren't of great scientific value. A more sophisticated mind understands that the scientific importance of these images was enormous, because it inspire hundreds, if not thousands, to do science as their calling.

        Ahem, NASA put a visible light camera on Juno specifically for "public science and outreach and to increase public engagement [wikipedia.org]".

      • No way close to accurate. Galileo took much better images of Jupiter despite the jamming of the antennae. And cassini without a doubt has taken images of Saturn and all it's moons so much better than Voyager it is not even plausible that the opposite is true.

        Voyager was amazing, but it was only a flyby mission lucky enough to enjoy a once in a lifetime alignment of all the outer planets.

    • That is an exaggeration. In the few hours of closest approach, they made some nice images. But Junocam's images are comparable [cloudfront.net].
      Juno will be able to study Jupiter in much more detail than the Voyagers ever could achieve in their brief flyby.

      The Voyagers are still listed as working, but they had their issues. Voyager 2's scan platform seized during the Saturn flyby, causing a loss of some of the planned observations.

  • by wisebabo ( 638845 ) on Saturday February 18, 2017 @07:57AM (#53891457) Journal

    So if they aren't going to be using the main engine for a major trajectory shift, does this mean that more fuel is available for the thrusters?

    In my long (non) professional career of following of various space programs, it always seems that the limiting factors to a mission is 1) the availability of fuel for the thrusters (for minor course corrections, attitude control/dumping of momentum) and 2) how many reaction wheels are still working (although there have been creative solutions such as using sunlight pressure for attitude control). If Juno's thrusters same the same fuel (and fuel tank!) as the main engine then perhaps it now has access to a much larger supply and can conceivably last a long long time. :)

    Of course, Juno's limiting factor WAS the intense radiation it was going to have to have faced but perhaps the new orbit has reduced that substantially. In fact, if there IS a lot more fuel available, perhaps it can use the fuel (once the primary mission is over) to get it out of the high radiation regions (perhaps by some creative gravity assists from the Galilean moons) and perform a multi-year "tour" of the Jovian system. This would possibly make up for the scientific tragedy that befell the Galileo probe when its high gain antennae didn't open and the data rate dropped by (three? more?) orders of magnitude. It'd be fantastic to get some really good pictures of Europa (life!) and Io (volcanoes!).

    Or just put it in a relatively distant parking orbit around Jupiter and (because it's solar powered) let it monitor the Jovian system for (hopefully) decades

    • by Anonymous Coward on Saturday February 18, 2017 @08:10AM (#53891497)

      The life limit for Juno is radiation. You need to drive it into Jupiter before the flight computer fails. There will be NO chance for a moon tour, because Juno didn't follow the very stringent planetary protection process you'd need if you were going to Europa. That's why it's being destroyed, rather than "run til it falls apart" - they don't want to crash into Europa and contaminate it.

    • So if they aren't going to be using the main engine for a major trajectory shift, does this mean that more fuel is available for the thrusters?

      Maybe, maybe not ; for a number of possible reasons.

      (1) Do the main and attitude drive systems use the same fuels? For the large number of anticipated firings for the attitude thrusters, you'd maybe go for reliably hypergolic fuel/ oxidiser couples (i.e., on contact, they ignite). But for the main engine with only a handful of planned firings you might choose a mono

  • A. You read it out loud, with an accent Improvise the rest.

    "Juno, Jupiter Probe won't come closer, after all."

    Then read the proper translation: "You know, Jupiter probe won't come closer, after all. Bastards!

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