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End of an Era in Planetary Exploration?

While both Alan Stern and Glen Fountain admitted to having anxious moments over the weekend when New Horizons went silent, it became clear at yesterday’s news conference that those moments were short and quickly subsumed with ongoing duties. Stern is principal investigator for New Horizons, and the man most closely identified with making the mission a reality, while Fountain is project manager for New Horizons at JHU/APL in Maryland. It was Stern who pointed out that the spacecraft has been in safe mode a number of times already.

Nine times, as a matter of fact, since launch, although as of yesterday we are back in the realm of normal operations. So the circumstances were not unfamiliar even if this safe mode came so close to destination that it raised inevitable concern and a flutter of worry on Twitter. Stern said he was in the control center six or seven minutes after getting the call that something was wrong. It also turns out that this was the first safe mode occurrence in which the backup computer was involved. So what exactly happened? Here’s Fountain’s explanation:

On the third of July we were preparing for the main event, with encounter mode starting on the 7th. That means loading those commands that are sequenced to get observations from the 7th of July to encounter and on through July 16th. This is a single command load that was to be put on the primary as well as the backup computer.

We had already loaded to the backup and on the 4th were loading to the primary computer, while at the same time taking data we had not been able to get down to the ground and compressing it, to free up the rest of the recorder for all the other data. So we were doing multiple things on the processor at the same time, and as we were doing the compression, the computer couldn’t handle the load. The processor said it was overloaded. The spacecraft then switched to the backup computer and went into safe mode, exactly as it should have.

Thus a timing conflict in the spacecraft command sequence is the culprit. Stern said that the data loss was minimal, with all science operations for Sunday and Monday lost as well as part of Saturday. Altogether, New Horizons lost 30 observations out of a total of 496 scheduled to be made between July 4 and the end of the close approach (the last of these occurring two days after the flyby). Because the team weighs the value of observations according to how close to the planet they are made, these lost sessions aren’t critical, and Stern figures the mission has experienced zero impact in terms of its highest priority science.

“We wish this hadn’t occurred,” Stern added,” but as PI, I can tell you that this is a speed bump in terms of the total return we expect from this flyby. We’re looking forward now to getting back to data collection. Pluto and Charon are already surprising us with their surface appearance.”

Science observations resume today at 1234 EDT (1634 UTC). Meanwhile, we have images captured by the Long Range Reconnaissance Imager (LORRI) between July 1 and 3, which were released immediately after the news conference.


Image: The left image shows, on the right side of the disk, a large bright area on the hemisphere of Pluto that will be seen in close-up by New Horizons on July 14. The three images together show the full extent of a continuous swath of dark terrain that wraps around much of Pluto’s equatorial region. The western end of the swath (right image) breaks up into a series of striking dark regularly-spaced spots, each hundreds of miles in size, which were first detected in New Horizons images taken in late June. Intriguing details are beginning to emerge in the bright material north of the dark region, in particular a series of bright and dark patches that are conspicuous just below the center of the disk in the right image. In all three black-and-white views, the apparent jagged bottom edge of Pluto is the result of image processing. The inset shows Pluto’s orientation, illustrating its north pole, equator, and central meridian running from pole to pole. Credit: NASA/JHUAPL/SWRI.

The image below adds color to the July 3 LORRI image using data gathered by the Ralph instrument, which performs visible and infrared imaging and spectroscopy.


Be sure to read Dennis Overbye’s fine essay in the New York Times on what New Horizons’ flyby of Pluto means in the larger scheme of planetary exploration (you also get the benefit of a video Overbye produced). I owe a lot to Dennis Overbye, whose Lonely Hearts of the Cosmos (HarperCollins, 1991) reignited my long-standing ambition to move from technology writing into astronomy and astrophysics. In the Times essay, he sees New Horizons as the beginning of the end of at least one phase of human exploration.

Beyond the hills are always more hills, and beyond the worlds are more worlds. So New Horizons will go on, if all goes well, to pass by one or more of the cosmic icebergs of the Kuiper belt, where leftovers from the dawn of the solar system have been preserved in a deep freeze extending five billion miles from the sun…

But the inventory of major planets — whether you count Pluto as one of those or not — is about to be done. None of us alive today will see a new planet up close for the first time again. In some sense, this is, as Alan Stern, the leader of the New Horizons mission, says, “the last picture show.”

We are at the edge of a vast sea, as Overbye notes, the one that separates us from the stars. Innumerable explorations await us as we learn more about the Solar System and push outward into the Kuiper Belt. But what a poignant moment as we realize that of the nine ‘classical’ planets (let’s not argue about ‘dwarf’ planets for now), there will never be another moment when one swims into focus for the first time. Let’s cherish the week ahead, and hope that one day humans will experience a similar kind of moment with a new planet in a new solar system.


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  • ljk July 7, 2015, 9:59

    ‘Direct From Pluto’: Science Channel to Air New Horizons’ Flyby Images

    by Robert Z. Pearlman, collectSPACE.com Editor | July 07, 2015 07:30 am ET

    With less than nine days to go in its nine-year journey to Pluto, NASA’s New Horizons spacecraft is on the verge of delivering the first up-close images of the mysterious dwarf planet.

    And when those historic images arrive on Earth, they are set to star in a new hour-long special, “Direct from Pluto: The First Encounter,” premiering on the Science Channel on Wednesday, July 15, at 10 p.m. ET/PT.

    “Science Channel viewers will see the very first close-up images of Pluto’s surface and its moons, and learn more as leading experts discuss the previous planet’s status as well as uncover some surprising research,” the channel described in a release shared with collectSPACE.com.

    Full article here:


  • Randall Jacques July 7, 2015, 10:20

    If the probe is allowed to continue it’s mission into the Kuiper Belt when would its next encounter be? I turned 50 this year so I wonder if I’d be alive to see pictures of Sedna or whatever KBO it may encounter.

  • ljk July 7, 2015, 10:25

    I presume New Horizons is capable of handling the encounter on its own and beaming the data back to Earth in case it loses communications with the home base? The Voyagers were capable of that with their antiquated onboard computers, so something made in 2006 should be even better at it.

    Mariner 7 temporarily stopped transmitting to Earth just one month before its flyby of Mars in August of 1969 due to the explosion of one of its batteries, yet it recovered in time to image the Red Planet up close. Mariner 4, which we will celebrate its 50th anniversary as the first space probe to successfully flyby and image Mars the same day NH flys through the Pluto system, had all sorts of glitches along the way before arrival. So NH is just following tradition. :^)


  • ljk July 7, 2015, 10:40

    Artists’ views of Pluto just before we arrive:


    I distinctly recall the color of Pluto being described as “yellowish” in the 1970s. Based on the images seen from NH so far and how every human interprets color, that doesn’t seem too far off.

    The Science of Pluto: The Sails of Charon (Part 2)

    By Leonidas Papadopoulos


    To quote:

    Another great unknown surrounding Charon is the lack of any perceptible atmosphere. Previous observations have shown that contrary to its planetary companion, the faraway moon lacks the presence of an atmosphere.

    Yet newer theoretical studies have provided tantalising evidence that Charon may indeed be sharing the same atmosphere with Pluto!

    “There is a large body of [scientific] literature by atmospheric modelers going back to the late 1980’s which show that atmospheric molecules and atoms for that matter that are escaping Pluto’s atmosphere, have to pass the orbit of Charon,” commented on the subject Dr. Alan Stern, principal investigator for New Horizons mission at the Southwest Research Institute, in Boulder, Colo., during a recent NASA Google+ Hangout.

    “And much like a binary star system, Charon’s gravity can pull some of that atmospheric gas into orbit around itself and even onto the surface of Charon and create a secondary atmosphere [there] … It would be fantastic if we discovered something like this. Never in the history of planetary exploration have we seen two planetary bodies with a shared atmosphere, like what we may see in the Pluto system. It would be quite a wonderland!”

  • Dmitri July 7, 2015, 11:00

    If everything has been discovered is there anything left to be discovered?

    I would compare New Horizon Pluto pass by to Columbus landing in Cuba. It’s just a beginning of the whole new era we can’t even grasp of. It took humanity 400 years since Galileo to inspect all the 9 planets in close by and most groundbreaking progress has happened in last 54 years.

    This reminds ESTCube-1 slogan “To Pulto in 5 years”. It has such deep meaning and consequence as a goal or implication of implementation on the whole space (exploration) industry.

    It might be true space exploration in current operation mode will be past as the miniaturization and availability of space grade equipment is more accessible to wider organization meaning greater competition by different (new) players leading to change in approach how unmanned space exploration will be conducted. Subsequently it will put into pressure to reach the destination in shorter time span, explore in-situ for longer periods (even beyond human life time), opening for different players to set their own (scientific) goals w/o (current) long wait from conception to operation.

    The sooner reaching & exploring space becomes as wide spread industry, the more results will be achieved. It’s not a short run undertaking. Most probably this is assignment with 150-300 year horizon. Note how much the world has changed in every 70 years.

    To Pluto in 5 years!

  • J. Jason Wentworth July 7, 2015, 12:06

    I grok this. For everyone after us (even those who are very young children now), there won’t be–except in old books, now of historical interest only–any artists’ renderings of what the planets and moons of our solar system *might* look like; they will always have the photographic reality right at their fingertips. For them, there will never have been any mystery as to what we might find upon visiting those worlds, and I’m glad to have been here when that veil was parted for all of the planets and moons. Also:

    We were privileged to be the ones who finally got to find out with certainty–and even to actually see, in some cases–that planets *do* exist around other stars. The most amazing part of this, for me, is that it was done using *existing* Earth-based telescopes fitted with amazing new electronic sensors, not the expensive lunar-based ones that were predicted to be necessary to -maybe- barely see Jupiter-sized worlds around other stars (even as late as the 1970s, many astronomers still thought that the only way to confirm the existence of such planets would be to travel to the stars!).

  • Paul Gilster July 7, 2015, 12:15

    Randall Jacques writes:

    If the probe is allowed to continue it’s mission into the Kuiper Belt when would its next encounter be? I turned 50 this year so I wonder if I’d be alive to see pictures of Sedna or whatever KBO it may encounter.

    It won’t be Sedna, but the plan is indeed to target a KBO after Pluto/Charon. The trick so far has been finding the right object, but we should be hearing more about New Horizons after the flyby of Pluto is over. And then there’s the New Horizons Message project, on which I’m pleased to be one of the advisers:


    and the main site:


  • lepton July 7, 2015, 12:21

    Randall, KBO encounter will happen in just a few years, IIRC, definitely within our expected lifetime.

    I wish we can find life outside earth. :-)

  • Christopher L. Bennett July 7, 2015, 12:52

    I’m not so convinced that this is the end of planetary discovery in the Solar System. There could still be planet-sized objects out in the Kuiper Belt, scattered disk, or Oort cloud.

  • Joe Moran July 7, 2015, 12:57

    It’s only an end of an era if one considers Pluto the last major planet rather than the first member of the Kuiper Belt to be explored. One’s choice of narrative invokes the old debate. Maybe it’s a generational thing, I don’t know. I’m forty years old, grew up with Pluto as the ninth planet, and I have no problem regarding it as being properly a member of the Kuiper Belt. So from my perspective, NH will provide a first look at a locality in that belt, one that hasn’t been reworked by orbital capture like Triton was.

  • Al Jackson July 7, 2015, 13:36

    Pluto puts me in mind of Robert Heinlein’s Have Space Suit will Travel. I was a senior in high school when that came out. Heinlein’s last ‘juvie’ for Scribner’s. It’s was serialized in F&SF with two covers by Ed Emshwiller.
    Pluto is the background of one of those covers. Emsh did the dust jacket for the hardback.

  • James M Essig July 7, 2015, 14:08

    Awesome! I used to spend days in elementary school in the late 60’s and early 70’s fantasizing about missions to Pluto. I was one of those unsophisticated students who achieved modest report card grades because I was to busy thinking and feeling about space travel instead of focusing on my homework. None-the-less, another childhood dream is about to be realized this coming week with the NH mission. CooOOOOOooL!

  • Alain July 7, 2015, 14:46

    Doesn’t the spot on pluto equator look like huge mountains?
    Could the dark spot be umbras?
    Could pluto be a Japet on steroids?

  • ljk July 7, 2015, 15:26

    Check out the depiction of Pluto as imagined by space artist Chesley Bonestell from the opening to the 1953 science fiction film The War of the Worlds:


    Note that while the color of Pluto in the 1953 version does not match what we are seeing from New Horizons, there are four dark spots in a curving line along the right side of the world. Hmmmm.

  • Robert Clark July 7, 2015, 16:13

    Thanks for that well written expression of the excitement that comes from astronomy.

    Bob Clark

  • Isaac Kuo July 7, 2015, 16:56

    I’d consider it the end of an era – it is the last of the “classic” planets to be visited. Even if Eris is still out there, and other large round bodies, Pluto was the last “classic” planet to be discovered before the Space Age.

    But this is just an arbitrary distinction. There are still major milestones awaiting. The flyby missions have only given us a partial view of Triton, in particular. We have not landed probes (much less boots) on Mercury, Mars’s moons, Jupiter’s moons, Uranus/Neptune’s moons, and of course Pluto/Charon/etc. The only gas giant we have directly visited with an atmospheric entry probe is Jupiter.

  • Brett Bellmore July 7, 2015, 17:46

    Well, if this is the last planet we’ll see close up for the first time, that still leaves most of the planets to actually VISIT for the first time; No human has been beyond Moon orbit, after all.

    And after we’ve visited them all, there’s colonizing them.

    So, no, I don’t think this is the end of planetary exploration. The end of the beginning, maybe.

  • Brett July 7, 2015, 23:59

    I’m sad there’s no planned mission to either Uranus or Neptune – both would benefit from a Cassini-style orbiter mission (or even a cheaper one).

  • DCM July 8, 2015, 4:48

    At least I lived long enough to see this moment.

  • Jim Early July 8, 2015, 8:52

    While this will be the last images of a new planet in my lifetime, the younger members of the audience should not give up hope. A sparse coherent array of ten meter space telescopes should be able to image planets in near star systems. For 100 km resolution the array would need to be 1000 km in diameter.
    We can deploy this technology in two to four decades.

  • ljk July 8, 2015, 9:39

    Brett Bellmore July 7, 2015 at 17:46:

    “So, no, I don’t think this is the end of planetary exploration. The end of the beginning, maybe.”

    Your last sentence contains almost the very words used at the end of the classic 1959 science fiction film, Destination Moon, which is celebrating its 65th anniversary this year.

    In fact the ending of DM was deemed good enough to be shown among a small collection of other beautiful film end titles here:


    And here is a collection of photographs from Life magazine showing ballet dancers on the lunar set of DM, just because:


    Meanwhile we have our first rough but real map of Pluto, with things only to get much better after next week:


  • ljk July 8, 2015, 10:01

    A good summary of the New Horizons flyby of Pluto here:


    Two articles on NH at Pluto next:



    A scientist has waited a decade to explore Pluto with an instrument onboard NH:


  • ljk July 9, 2015, 8:39

    In this article from July 7 where The Planetary Society explains its role in having made New Horizons happen:


    There is some very interesting artwork showing what it might have been like if Voyager 1 had been aimed at Pluto in 1986 instead of discovering that Titan is really cloud-covered in 1980:


    I and other are becoming convinced more and more that not exploring Pluto almost three decades ago when the chance was available was a mistake. When you have the chance to explore a new world you take it. You don’t know what can go wrong, including human shortsightedness (my polite word for stupidity) . If New Horizons had more than just a glitch on July 4, my words here would be even more pertinent.

  • ljk July 9, 2015, 10:26

    One Week to Pluto: An Outcast World, In From the Cold (Part 2)

    By Ben Evans

    Tomorrow morning, less than 100 hours will remain before the first machine fashioned by human hands completes the initial reconnaissance of the last of the Solar System’s “traditional” nine planets.

    NASA’s New Horizons spacecraft—launched 9.5 years ago, way back in January 2006—is approaching a 14 July rendezvous with the dwarf world Pluto, its binary companion Charon and a system of four tiny moons: Nix, Hydra, Kerberos and Styx. This entire group are named in honor of key figures and locations associated with the ancient Greek and Roman underworld and this nomenclature is entirely fitting, for they reside in one of the darkest, coldest and gloomiest parts of the Sun’s realm.

    However, this region has drawn new light in the past couple of decades, following the discovery of the long-hypothesized “Kuiper Belt” of objects beyond Neptune, and as discussed in yesterday’s AmericaSpace Pluto history article this has thrown the nature of Pluto as a “classical” planet into question. As the mission enters its final days before Closest Approach, AmericaSpace’s New Horizons Tracker and a series of articles by Mike Killian, Leonidas Papadopoulos, Paul Scott Anderson and myself will cover the discovery and exploration of Pluto and the unfolding developments as the spacecraft seeks to make this unknown world known.

    Full article here: