We made it to Jupiter!

July 5, 2016 • 8:20 am

Consider this: a lineage of apes began making tools a couple million years ago, wresting stones from the earth to make crude choppers and axes. A bit later we had arrowheads, and then spears. And then the wheel.  Only six thousand years after the wheel, those apes had progressed to where they could wrest sufficiently diverse materials from the Earth and air to make rocket ships and space probes, sending them 3.6 billion miles away and delicately placing them into orbit around the largest planet in our Solar System. Yes, at 10:19 last night Chicago time, the Juno space probe was deliberately slowed down and successfully captured by Jupiter, where it will orbit, taking photographs of the Giant Planet from beneath its gas clouds. It will see, for instance, what kind of core Jupiter has, and whether there is any water (aka ice), or traces of past water. After two years and just 37 orbits (it’s a big planet), the craft will die a glorious death, plunging toward Jupiter and burning up—mission complete.

What thrills me, and fills me with admiration for our species, is that we did this solely with our brains and with materials that could be found only under the ground or extracted from the air. It is an absolutely stunning achievement, one that makes me tear up. It’s celebrated in today’s animated Google Doodle:


If you’re really into this, go watch the livestream from NASA’s Jet Propulsion Lab.

To read more about this mission, see today’s article in the Atlantic, clearly written beforehand with the expectation of success. (It was published two minutes after midnight last night—an hour after capture.) One quote to show the magnitude of this achievement. Look at the speed (my emphasis)!

“We just did the hardest thing NASA’s ever done,” Rick Nybakken, Juno’s project manager, could be heard telling his colleagues amid cheers in the moments after the spacecraft completed its task.

The successful maneuver, known as an orbital insertion, was executed via a series of pre-programmed commands that engineers transmitted hundreds of millions of miles to the outer solar system. The move, which represented the riskiest moment in the mission since Juno launched in August 2011, involved firing the spacecraft’s main engine so that the probe could slow down enough to leverage the planet’s gravity for a shift into its orbit.

Had things gone differently, Juno would have spun off into space. There was plenty else that could go wrong. The New York Times, for instance, kept this running list of doomsday possibilities in the hours leading up to the maneuver: “Juno blows up… The engine doesn’t fire at all… It crashes into something… It flies too close to Jupiter and is ripped to pieces… The computer crashes.”

Confirmation that the probe had successfully entered Jupiter’s orbit came with a curt three-second beep. About 45 minutes later, it was clear that the probe had cleared another key hurdle; its huge solar arrays had successfully turned back toward the sun—the necessary orientation to keep the spacecraft going. Now, Juno is embarking on a science mission that will take humankind closer to Jupiter than ever before, within about 2,600 miles of the planet’s cloud tops.

Even before tonight, however, Juno had already made history. It is the fastest human-made object ever built; at a speed of 165,000 miles per hour, it’s five times faster than New Horizons, seven times faster than Apollo 11, and 122 times faster than the Concorde. In January, Juno broke the record to become humanity’s most distant solar-powered envoy. “Prior to Juno, eight spacecraft have navigated the cold, harsh under-lit realities of deep space as far out as Jupiter,” NASA wrote at the time. “All have used nuclear power sources to get their job done.”

Here’s the tense situation at mission control, and the joy when success was achieved. I am so happy this succeeded! “Welcome to Jupiter” indeed! I can’t wait for the photos.

Here’s NASA’s time-lapse movie, taken by Juno, showing its approach to the planet and a look at its moons—the same moons Galileo saw through his telescope so many years ago (cheesy music by Vangelis). It was taken from June 12 to June 29.

And here’s Juno with its instruments (click to enlarge); this is on the NASA site, and describes the solar panels and why they’re so big (you can guess). The goals of the mission can be seen here.


42 thoughts on “We made it to Jupiter!

  1. “After two years and just 37 orbits (it’s a big planet), the craft will be set down gently on the surface of the planet—mission complete.”

    Actually, at the end of the mission in February 2018, Juno will plunge into Jupiter’s atmosphere where it will burn up in a fireball. NASA did the same thing with Galileo, Juno’s predecessor, and for the same reason: we don’t want Earth microbes to contaminate any of the large icy moons.

    But yes, it’s an accomplishment that we as a species can be proud of.

    1. A couple of the phrases “Red Planet” and “set down gently on the surface of the planet” perhaps confuse a Jupiter mission with a Mars mission?

  2. Yeah, but how about a shout out for the camera crew that followed along to take those pictures of Juno & Jupiter.

    What have they been doing for the past five years, chopping liver?

  3. > set down gently on the surface of the planet

    What surface? Juno will “gently” immolate itself in Jupiter’s atmosphere.

    And don’t dis my boy Vangelis. He did the music for the original “Cosmos”.

  4. Wonderful, really wonderful, but, yes, you’re right, the music is dreadful… Who bloody well chose it?

  5. These are the things we need to remind our republican friends of every time they claim govt. can’t do anything. Retaining a memory is one of their greatest failures.

    1. Yes, given the right people (well trained and highly motivated) and adequate funding, government can work as well or better than the private sector. Unfortunately, Republicans do their best to assure that both are lacking.

      1. “Intellectual curiosity should not be subsidized (or WTE).” – Ronald Reagan

        Unless of course a buck can be made from it. Yep, from the apotheosis of intellectual curiosity and free/critical thinking – intellectual curiosity has to first exist before it can possibly be subsidized.)

        And of course, if one wants to be competent to actually DO something to make a Juno a reality, one should become not a STE(A)M type but a Romneyesque MBA/JD venture capitalist type (sarcasm). Except there’s no money to be made (yet) from such an interplanetary enterprise.

    2. Obama said something once along the lines of, “I don’t care if it is a Government program, I care whether or not it works.”

      There’s crappy Government programs and crappy businesses, just as there’s wildly successful enterprises in both areas. The fact that Government has DARPA and NASA under its belt pretty much destroys any argument that Government is always inept. Plus, how many private businesses have profited off the discoveries of those two Government agencies? It’s certainly a significant portion of the world’s GDP at this point.

    3. My father used to bug me about how the govt couldn’t do anything right. I would ask him how about the man on the moon (This was years ago…), the interstate hiway system, medicare (which he profited from) and the internet, among others. Being my father, he did not back down, but he didn’t go on either.

  6. This is very very cool, and I look forward to learning more about ‘what lies beneath’ the mysterious clouds of Jupiter.

    1. Technically I think the Apollo returns with their interplanetary speed (near enough) atmospheric braking must have been up there, but I don’t really know.

      But bleeding off 40,000 km/h by compressing and super-heating the air ahead of you is one crazy way to brake a craft. [ https://en.wikipedia.org/wiki/Apollo_10 ]

  7. The water content will tell us where Jupiter formed, perhaps further out as the Nice model for our solar system predicts, and an understanding of the core may tell us how the planet formed.

    Spot the Sun task:

    The reverse slingshot to brake the speedy craft is a nice touch to the giant mission. Presumably it is because Juno is looking back, waiting for Jupiter to catch up, that the planet has the sunlight on the right side. (The moons are orbiting counter clockwise relative to astronomical north, as the planets in our system.)

    1. … and where (and how) Jupiter formed will be ground truth for understanding if and how other planet systems have planet migrations.

  8. These robotic space missions in our tool box of methods to explore the deepest regions of the solar system are proving to be very valuable and can yield incredible science information and discoveries is truly exciting.

    1. Casual lay person commenting alert

      In answer to your two questions I gather from my reading it’s “No” & “No” 🙂

      Juno will be able to tell us about the atmosphere, presence of water, gravity field, magnetic field & the polar magnetosphere. From orbital effects on Juno we’ll be able to determine mass distributions within Jupiter & we’ll be closer to saying if there’s a so-called ‘rocky core’. But as to the Liquid Metallic Hydrogen [LMH] there’s no possibility of detecting this if it exists as proposed.

      There are two molecular hydrogen layers above the proposed LMH: There’s a 5,000 km thick hydrogen/helium gaseous atmosphere, then beneath that there’s a 1,000 km deep sea of fluid hydrogen [imagine that!] & only then do we reach the proposed LMH layer [the transitions I’ve described above are gradual & the ‘atmosphere’ part is defined by a pressure convention rather than a distinct change in properties from gas to liquid] – so I don’t see how the LMH can be detected – only inferred.

      Also we haven’t quite made any LMH in the lab yet although we’ve come close to a phase near the proposed LMH phase recently using diamond anvils. Thus the properties of LMH are purely derived from theoretical calculations up to now – nobody has made it & ran a current through it etc. The phase that’s been made has been tentatively called “dark hydrogen” – it’s slightly metallic and can conduct an electric current somewhat.

      Using the term “dark” is a bad idea that will confuse people – I hope it doesn’t catch on!

      1. The concept of LMH has been around for some decades & it’s been put forward as a room temperature superconductor for use in electronic circuitry. This makes my head spin – how does one make & constrain/contain LMH for use in commercial products? I wait to be amazed.

        1. First report that I know of, of the theoretical possibility of there being a metallic phase to hydrogen, dates back to 1935.
          Unfortunately, if the recent reports of metallic hydrogen in the laboratory are correct, this is going to be a phase stable at pressures of above 2.2 to 2.5 million atmospheres.
          This is less than optimistic for making room-temperature superconductors of this stuff.

          The possibility of detecting the presence of metallic hydrogen in the internal structure of Jupiter by close examination of the gravity field (giving the internal mass distribution) and of the magnetic field (assuming that to be produced by motions in the metallic liquid hydrogen, in a manner analogous to Earth) may constrain the phase diagram of hydrogen, pointing more closely to where to try to reach with experiments.

      2. Also we haven’t quite made any LMH in the lab yet although we’ve come close to a phase near the proposed LMH phase recently using diamond anvils.

        There are disputed claims – which is good, because it means there are multiple groups working at the problem from several directions.
        Late last year, one group claimed to have found evidence of metallic hydrogen at around 220 GPa ; a differnt group working the same general pressure regime claims not to have seen it ; reviewers pointed out some un-metallic behaviour (resistance increasing with decreasing temperature), which the first group suggests is because the metallic state is disordered, while the second group says it’s because metal hydrides are being formed in the reaction chamber (which is around the size of a human body cell).
        “Interesting times.”

    1. “Uniform” was one word that slipped through my mind watching the broadcast from Mission Control.

  9. After two years and just 37 orbits (it’s a big planet)

    The length of the orbits isn’t because it’s a big planet. It’s to manage the radiation exposure of the spacecraft’s electronics, despite the cm-thick titanium radiation shields surrounding the critical bits.
    Knowing the cost of launch – in the order of thousands of dollars per kilogramme – you can imagine how they tried to pare that radiation shield down, and use other techniques to optimise the lifetime of the spacecraft.
    But the highest energy (and most penetrating) of that radiation is strongly concentrated by (using standard hyperbole, for once appropriate) mighty Jove’s tremendous magnetic field into relatively narrow belts somewhat analogous to the Van Allen belts around Earth.
    This also dictates the polar orbit – the radiation belts are narrower, and speeds higher, reducing the net dose.
    But the main tool to managing that radiation is to have high perijove speeds (speed at closest approach to Jupiter), and to get that you need a long orbit going out a long way. In this case, the far point on the final 14-day orbit will be about 2 million km out, beyond the orbit of Callisto. And of necessity, beyond the orbits of Ganymede, Europa and Io as well. All that crossing of orbits is why Juno will undergo a scheduled RUD in a pale imitation of Comet Shoemaker-Levy 9. The orbital plan also means passing the ring radii multiple times, but since they’re equtorial, they probably don’t add up to much in the mission’s risk accounting.
    I was trying to work out the apojove of the first orbit – scheduled for 53.5 days – but couldn’t do it in my head. It’s somewhere on the outside of 4 million km, I think.

  10. Wonderful achievement. Congratulations to the NASA team. Let’s hope the rest of the mission goes as well.

  11. As nearly as I can make out from the mission homepage, Juno does not make photographs “from beneath its gas clouds”. The orbital perijove [lovely word] was to be about 4200 km above the 1-bar altitude in the atmosphere. Not sure where the visible cloud tops, but Juno surely could not enter them and live for another planet.

    It also appears that the camera[s] have little scientific value — they are there to give us a show for our taxes. The cameras are also the least-hardened electronics, so likely to go dead before the various radiometers, magnetometers, and gravity probes.

    Also interesting how risk-averse some design criteria were, even for low-probability events. Presumably the agency ethicists are active! The germophobe plunge to protect the Jovian moons stands out. [Given that we’ve surely sullied Mars, that’s a nice gesture. The use of solar panels surely complicated the design and presumably makes the mission success a bit less more problematic. But NASA took such hits on use of radiothermal power on previous missions, they are evidently making this power source a last resort. Even though the likelihood of accident on launch, or especially on slingshot flybys of earth are remote, the agency takes heroic measures to avoid nuclear contamination.

    1. I agree that JunoCam was partly a PR exercise, but it may prove to be very important anyway. It can image around 15 km/pixel at closest approach which is a significant improvement over Hubble’s imagery of Jupiter @ approx 120 km/px.

      It’s a pity we’ll not see any Jovian balloon beasties with that camera unless they’re iceberg sized 🙂

      I’m not sure it’s true that solar panels were selected over a Pu-238 power source because of nuclear contamination of Earth should there be a mission failure. The Pu-238 was [& still is?] in short supply, solar cell tech is much improved & the panels add stability when deployed – I read that the panels were actually economically preferable [although I don’t know what if any is the extra weight cost of panels]

      I also have this sneaking suspicion that the US military, NSA & CIA require the Pu-238 for the powering of their black projects such as Earth orbit spy & illegal anti-satellite systems, sleeping submarine robots, long life anti-submarine detectors & stuff I can’t imagine. There is no record open to the public of how much Pu-238 is in stock or being made [production restarted around 3 years ago after a 25 year gap]

      1. Thanks for the information. I’m pretty sure that we’re both excessively cynical. Each in our own way — mine is recalling the Chicken Little flap each time s spacecraft flashes by earth.

  12. It is an absolutely stunning achievement, one that makes me tear up.

    I feel exactly the same, Jerry. In a world where people seem so prone to screwing up our entire shared human endeavor at nearly every turn, it’s immensely gratifying and uplifting when we get something so right and accomplish things like this. Go NASA!

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