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Japan Releases AKATSUKI's Pictures of Venus (discovery.com)

Posted by samzenpus on from the worth-a-thousand-words dept.

astroengine writes: The Japanese space agency JAXA has released a confirmation that their Venus mission Akatsuki did indeed enter orbit at Venus on Dec. 7 (JST) — releasing unprocessed images of the Venusian atmosphere as it entered orbit. The spacecraft is currently in a highly-elliptical 13-day, 14-hour orbit around the planet, coming within 400 kilometers (248 miles) at its closest point and reaching 440,000 kilometers (243,400 miles) away at its farthest. This mission has just become the most unlikely success story of 2015 after "missing" its intended Venus orbit way back in 2010.

44 comments

  1. Learn to spell "its." by Anonymous Coward · · Score: 1

    Spelling matters.

    1. Re:Learn to spell "its." by dejitaru · · Score: 1

      it's got 2 out of 3 right

    2. Re:Learn to spell "its." by R3d+M3rcury · · Score: 1

      It's!

    3. Re:Learn to spell "its." by Anonymous Coward · · Score: 0

      HTML matters too. You'd think Discovery Communications could afford to hire someone who knows how to link a simple image without the need for JavaScript (or a dozen in this case).

      Protip: Images, links and texts can, and should, be done purely with HTML.

    4. Re:Learn to spell "its." by Anonymous Coward · · Score: 0

      Spelling (noun); the process or activity of writing or naming the letters of a word.

      Spelling and punctuation are not the same thing. "It's" and "its" are spelled the same, but punctuated differently. Learn the difference.

  2. Jebediah Approves by Valkyre · · Score: 2

    Looks a lot like what I had to go through to save my Jool mission. Congrats guys.

    --
    What the heck is a 'sig'?
    1. Re:Jebediah Approves by Fire_Wraith · · Score: 2

      Yes - the lead engineer on this did some amazing maneuvers to salvage the mission after the main thruster failed. It was definitely something straight out of Kerbal Space Program, and totally cool.

    2. Re:Jebediah Approves by Valkyre · · Score: 1

      I don't suppose you have a link to a play-by-play of the original/altered mission path?

      --
      What the heck is a 'sig'?
    3. Re:Jebediah Approves by Anonymous Coward · · Score: 0

      Nah, it's not a proper KSP mission until someone has to get out and push.

    4. Re:Jebediah Approves by Fire_Wraith · · Score: 4, Informative

      Not to the original, but here's a link to the image of the series of maneuvers they had to do to get into orbit, over five years:
      http://goo.gl/ONZpns

      Full article here: http://gizmodo.com/tonight-is-...

    5. Re:Jebediah Approves by Triklyn · · Score: 1

      well... calculations hard, and my EVA has plenty of delta-V.

  3. isn't this revenge porn for nerds? by turkeydance · · Score: 2

    Akatsuki releases images of Venus...did Venus give her permission?

    1. Re:isn't this revenge porn for nerds? by Anonymous Coward · · Score: 1

      Don't worry, her privacy is protected by the mosaic filter on her pubes as per Japanese law.

    2. Re:isn't this revenge porn for nerds? by Anonymous Coward · · Score: 0

      No. That would be a picture of Uranus.

    3. Re:isn't this revenge porn for nerds? by Anonymous Coward · · Score: 0

      Japan decided to do away with all the bad Uranus jokes by renaming it to Urpantsu. Kyaaa!

  4. Venus made of two planetary halves put together by Dishwasha · · Score: 1

    I never knew that Venus had a big seam running perfectly in the middle of it.

    1. Re:Venus made of two planetary halves put together by Sowelu · · Score: 1

      Yeah, I'm wondering wtf that line on the micrometer one is, since it doesn't show up on the UV one. Artifact with that particular camera? Something that they will correct with processing?

    2. Re:Venus made of two planetary halves put together by KGIII · · Score: 2

      It's obviously Photoshopped. I've seen Venus in a telescope and it's not black and white.

      --
      "So long and thanks for all the fish."
    3. Re:Venus made of two planetary halves put together by serviscope_minor · · Score: 2

      Obviously a sarcastic remark, but curiously Iapetus actually DOES have a seam running perfectly in the middle:

      https://en.wikipedia.org/wiki/...

      --
      SJW n. One who posts facts.
    4. Re:Venus made of two planetary halves put together by MachineShedFred · · Score: 2

      That's just an injection mold seam line - it's perfectly normal.

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
    5. Re:Venus made of two planetary halves put together by Anonymous Coward · · Score: 0

      That's the X-wing accessible path to the coolant system.

  5. Re:They learned almost too late... by Punko · · Score: 1

    Nope.

    This post has absolutely *nothing* to do with the topic.

    I'm sure this has never happened before.

    --
    If only we could fall into a woman's arms without falling into her hands
  6. As for why... by Rei · · Score: 5, Informative

    ... all of this trouble happened, the Planetary Society blog had a nice detailed writeup a while back. The "short" of it? Akatsuki has a new type of primary thruster based on ceramics to withstand the heat rather than exotic materials like dicilicide-lined niobium as are normally used on these sorts of small hypergolic thrusters; they wanted to prove the new technology. You generally run thrusters a bit fuel-rich and inject it in such a manner as to try limit combustion near the chamber and nozzle walls to keep the temperature down. Well, the pressurant valve to the fuel tank didn't open all the way (they think it corroded) but the oxidizer pressure valve opened all the way. So the burn kept getting more and more oxidizer rich, meaning hotter chamber and nozzle walls way past the design limits, until they cracked and the nozzle simply flew off.

    The only reason they were able to salvage this was because another unusual choice they did: to save mass, they implemented a more complicated hydrazine (fuel) feed system, allowing them to use the same hydrazine suppy for the main engine as for the small monopropellant RCS thrusters (tiny, low-efficiency maneuvering thrusters). Because they did this, they were able to take the fuel that was planned for the main engine and route it instead to the RCS engines. While they're less efficient and much lower thrust, they had enough excess fuel to pull off the maneuver (after first making the craft lighter by dumping the now-unneeded oxidizer, of course!)

    --
    Nothing says 'welcome to the neighborhood' like a gunny sack full of dead squirrels.
    1. Re:As for why... by Sowelu · · Score: 1

      Hoping I have this stuff right, please correct me if I'm wrong...
      If hydrazine is a monopropellant (energetically decomposes with a catalyst), and they used it for both RCS and their main thruster, then why was there oxidizer at all? Is it an efficiency thing where it burns better with oxygen, or am I missing something?

    2. Re:As for why... by alantus · · Score: 5, Funny

      In other words, they diverted power to the plasma manifolds.

    3. Re:As for why... by Anonymous Coward · · Score: 2, Informative

      Hydrazine does burn hotter with oxidizer (thus faster exhaust gases, better efficiency), yes.

      (Incidentally, oxygen would not be the oxidizer of choice for a deep-space mission, since it will boil off -- dinitrogen tetroxide is the usual choice to go with hydrazine. Liquid at room temperature, with ignition on contact. Also horribly toxic.)

    4. Re:As for why... by Anonymous Coward · · Score: 1

      Yes.
      Decomposing hydrazine as a monopropellant gets you ~185s specific impulse.
      Burning hydrazine with nitrogen tetroxide gets you ~245s.
      Note: that's rough figures for relatively low tech chamber and nozzle designs ca. 1970s. Modern materials and CFD optimized designs can likely get >20% higher.

    5. Re:As for why... by Brett+Buck · · Score: 4, Informative

      Nice summary! I would note that the ability to interconnect the bipropellant hydrazine supply to the monopropellant engines is not an "unusual choice", it's common bordering on ubiquitous. Pretty much in order to provide this option as a backup.And it has been used in exactly this way (for more-or-less the same reason) in the very recent past.

    6. Re:As for why... by Rei · · Score: 3, Informative

      I can think of a couple examples of spacecraft where it's been used that way (the Planetary Society's writeup mentions MESSENGER and MRO), but not many. Most of the designs I've seen use separate systems, for simplicity and supposedly extra reliability (the irony here being that the lack of separation on the systems is what saved Akatsuki). Cassini, for example has fully independent systems - like Akatsuki its main engine is hydrazine/N2O4 and its RCS is monoprop hydrazine, but the RCS has its own separate tank.

      --
      Nothing says 'welcome to the neighborhood' like a gunny sack full of dead squirrels.
    7. Re:As for why... by Anonymous Coward · · Score: 0

      Aren't most oxidizers horribly toxic? What oxidizing agent isn't just as happy to oxidize you?

    8. Re:As for why... by maestroX · · Score: 1

      Venus taking hottie at the nozzle results into dumping unneeded oxidizer.
      Happens every day.

  7. December 7th? by ScentCone · · Score: 3, Funny

    Why do the Japanese always choose December 7th to travel long distances and invade places?

    --
    Don't disappoint your bird dog. Go to the range.
    1. Re:December 7th? by MachineShedFred · · Score: 1

      I suppose it makes it rather easy to predict an attack if you're ever in a kerfuffle with Japan again...

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
  8. Parent is quite related by Anonymous Coward · · Score: 0

    The monster from "It Conquered the World" was from Venus.

  9. White armed Hera by Anonymous Coward · · Score: 0

    The grand old lady was known in Homer's Illiad as 'white armed Hera', the wife of Zeus.

    1. Re:White armed Hera by deviated_prevert · · Score: 1

      The grand old lady was known in Homer's Illiad as 'white armed Hera', the wife of Zeus.

      Yes and Zeus and his sister Hera had a child which made Zeus jealous thinking that it would become a more powerful god than he. So he ate it. SOMEHOW I don't incest. child murder and cannibalism is how the Japanese managed to pull off the engineering marvel of using slow thrust over 5 years to salvage their mission to Venus though. But it might be how the US manages to send a manned mission to Mars if Donald Trump gets elected. Come to think of it he and his supporters are welcome to claim Mars provided they all homestead there permanently they can have it all to themselves. Oh and they can take along Tzar Putin while there at it! Credit where credit is due the Japanese are very insightful examining Venus over a long period of time. As the Sun cools it might become our next home until the Sun exhausts it's supply of hydrogen and swells up like Zeus in a rage and eats the planetary children that are too close.

      --
      This message was not sent from an iPhone because Peter Sellers really was a deviated prevert without a dime for the call
    2. Re:White armed Hera by Anonymous Coward · · Score: 0

      Not to inject politics into a good science thread, but think about it. Do you really want a world ENTIRELY populated by insane psychopaths existing next door to earth? Regardless of it's current usability, if people (however insane) live there it's usability will improve over time. Then it has a good chance at becoming a staging ground to retake their God-given right to their motherworld, (Aka. Earth.) after being isolated for generations from any form of good social environment. That's not the best idea in the world in my opinion. Now if they want to try and "colonize" a blackhole.....

  10. I hope they got permission by kelemvor4 · · Score: 1

    Othewise Itachi will be pretty pissed.

  11. A bit of a come down by Anonymous Coward · · Score: 0

    after the utterly spectacular imaging of Pluto by New Horizons. AKATSUKI is amateur hour in comparison.

  12. Naruto Will Stop Them by Anonymous Coward · · Score: 0

    Now that we know Akatsuki is hiding near Venus, Naruto will deal with them ... Believe It!