back to article Japan's Venus probe power plight panacea: Turn it off and on again ...and again and again...

The Japanese Space Agency (JAXA) has said it is shutting down two of the five cameras on its planetary probe around Venus due to power glitches. The Akatsuki craft has been in orbit around the acid-death world since 2015, five years after it was due to get there. The satellite's main engine failed mid-flight and it took …

  1. redpawn
    Pint

    Atoms?

    Any Intel Atom processors there in need of replacement?

    All kidding aside deep space probe teams have consistently scraped every last bit of data out of balky hardware. Congratulations for rescuing the mission and getting good data JAXA.

  2. Anonymous Coward
    Anonymous Coward

    Thank you for flying JAXA

    We trust you enjoyed your (acid) trip

  3. John Smith 19 Gold badge
    Unhappy

    "and will try turning them on then off again over time"

    Often works for me.

    Fingers crossed it works for them.

    TBH I'm a little surprised given the performance of JPL probes with design lives of a year turning in operating times of a decade.

    Issues with parts procurement?

    1. Destroy All Monsters Silver badge

      Re: "and will try turning them on then off again over time"

      It's JAXA, they are not there yet.

    2. BristolBachelor Gold badge

      Re: "and will try turning them on then off again over time"

      I tend to think that the 1 year lifetime is to allow for really pessimistic dependability/reliability analysis. Also you look good when it lasts much longer than expected. If you sell it as a 10 year mission, but only make it to 8, you look like a failure.

  4. PNGuinn
    Trollface

    five years after it was due to get there ...

    Well, all I can say is that's a good thing it wasn't made by Southern Rail ...

  5. TVU Silver badge

    Japan's Venus probe power plight panacea: Turn it off and on again ...and again and again...

    Let me guess, the Akatsuki probe has a Microsoft operating system.

  6. Anonymous Coward
    Happy

    FFS Commentards - get a grip

    JAXA have managed to get a sophisticated piece of equipment up and out of our atmosphere n gravity well and propel it a bloody long way through an inhospitable environment to another planet. They've managed to overcome serious challenges, the like of which us mere terrestrial Engineers never have to worry about.

    Good skills JAXA, damn good engineering and damn good science will result.

  7. harmjschoonhoven
    Unhappy

    Re: radiation environment

    Although Akatsuki was launched during a period of minimal solar activity, it has now endured a complete cycle of maximum solar activity with increased risk of radiation damage. Had it been launched five years earlier, the damage would have been much less.

    1. allthecoolshortnamesweretaken

      Re: radiation environment

      So, one space year is like seven dog years?

      (Joking aside, I'm still amazed that JAXA managed to fly the probe to it's destination without the main engine - who cares if it took a little longer?)

    2. bombastic bob Silver badge
      Devil

      Re: radiation environment

      I think part of the problem was the path it took to get there. It had a "missed approach", had to go around the sun or something... well that exposed it to Mr. Sun's nuclear blast furnace and thereby did potential damage to metal oxide insulators and whatnot. yeah.

  8. Christian Berger

    Different approach to it

    Apparently the Japanese are using the approach of sending out more cheaper probes than fewer more expensive ones. So they may have some failed ones, but that's not as big of an issue.

    It's of course noteworthy that such power glitches are nothing uncommon. Stray charged particles are common up there and can cause parasitic thyristors to fire, leading to a short circuit. Electronics for space is designed to detect that, remove the power for a bit, and turn it on again.

    1. Anonymous Coward
      Anonymous Coward

      Re: Different approach to it

      There's nothing in electronics more rad-hard than a JANTXV TO-5 outline relay. As I discovered when designing a circuit that needed to recover from a parasitic thyristor trigger event.

      There was also the time when we needed an actual, low power, low sensitivity thyristor for a circuit that had to function near a lightning simulator. We found one in a US catalog, expensive but still worth it as you don't want your dump circuit being prematurely triggered (ooh err miss...) and this was the easiest way to do it that avoided fibre optics. So we placed an order....

      Only to get calls, first from the US Embassy and then from an applications engineer. Because the thyristors we wanted were the cheap version of the ones you use to trigger nuclear weapons.

      1. BristolBachelor Gold badge

        Re: Different approach to it

        Yeah, but they're now telling me too design out the TO-5 relays. There have been a number of other, erm, happenings, so someone is going off them.

        As for crazy phone calls about why you want to use an LM139 compartor designed in 1960, who are you? and list every single person who will work on it, and every address the unit will ever be at, and...

      2. John Smith 19 Gold badge
        Unhappy

        "function near a lightning simulator. "

        Yes that would be the sort of environment that would be close to a nuclear weapon.

        Although Cryotrons are more like valves than power semiconductors.

        IIRC when such stuff is needed it's SOP to use cheap grade FO links and low power design tricks to run the thing as a floating ground. Horowitz & Hill "The Art of Electronics" is the usual reference for this stuff.

        1. bombastic bob Silver badge
          Boffin

          Re: "function near a lightning simulator. "

          "Yes that would be the sort of environment that would be close to a nuclear weapon."

          being tolerant of constant irradiation by a neutron source? well, lightning isn't neutrons, just high energy EMP. I wouldn't be surprised that hardening against both of them uses similar tech.

          1. John Smith 19 Gold badge
            Unhappy

            "I wouldn't be surprised that hardening against both of them uses similar tech."

            And you'd be wrong.

            EMP means a Faraday cage and ideally heavy grounding. Signal feed throughs have have to be designed with care.

            Neutron shielding needs a layer of stuff with lots of Hydrogen in it.

        2. Anonymous Coward
          Anonymous Coward

          Re: "function near a lightning simulator. "

          "IIRC when such stuff is needed it's SOP to use cheap grade FO links"

          It is now, but when the project I referred to started, they were very expensive. People tend to forget (or not be old enough to know) how much the price of electronics has come down. Or how much lower power consumption is these days.

          1. John Smith 19 Gold badge
            Unhappy

            "It is now, but when the project I referred to started, they were very expensive."

            Well H&H has been around since at least the mid 80's.I guess it would depend on what exactly you wanted to do, wheather it's data transfer for monitoring and analysis or if you're trying to drive something. Another classic was side stepping the need for a full ADC for a parameter and driving a Voltage/Frequency converter so an analogue signal shows up as a "drift" in the flashing rate.

            Driving stuff with short high power pulses remains quite tricky even today, especially in the sub ns range.

  9. JCitizen
    Flame

    Faster, Cheaper, Better errr...

    maybe not.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Other stories you might like