back to article Earth to Voyager 2: Standby for connection – after we tip this water out of the dish

The venerable Voyager 2 spacecraft is currently more than 19 billion kilometres from Earth, travels at 15 kilometres per second and talks to NASA’s Deep Space Network (DSN) at a torturously slow 160 bits per second. And today chatting to the probe got a little harder when the DSN node scheduled to log on – the Deep Space …

  1. jake Silver badge

    Rusty scuppers?

    Or just poor planning?

    1. lglethal Silver badge
      Boffin

      Re: Rusty scuppers?

      If you can tip it out easily, you don't need to add holes, which would reduce your "listening" ability. It's not like Canberra gets monsoonal levels of rain. ;)

      1. jake Silver badge

        Re: Rusty scuppers?

        "which would reduce your "listening" ability."

        Not as much as you might think.

        Every dish I ever came in contact with had weep holes in such places. From what I was told, virtually every such dish is pointed straight up in "storm lockdown" conditions, and seeing as storms are often associated with cold fronts, cold enough to freeze any standing water, they attempt to drain it away as fast as possible rather than ice things up, potentially buggering up delicate adjustments.

        1. Alan Brown Silver badge

          Re: Rusty scuppers?

          Canberra doesn't get much frost (if any at all - normally it barely touches freezing during winter) - more importantly it doesn't get much rain when it's that cold and it doesn't get much in the way of high winds either

          weep holes are fine, but they may drop water from the subreflector straight down onto the receiver electronics - which is "undesireable". Tipping it out avoids the sensitive bits

          1. jake Silver badge

            Re: Rusty scuppers?

            It doesn't take "much frost". One good freeze is enough.

            Said weep-holes direct the water away from the sensitive bits. Kinda like your roof & down-spouts.

            Besides, the receiver electronics are sealed in weather-proof boxes. Not even NASA is stupid enough to funnel rain water directly onto the circuitry.

            1. MikeTheHill

              Re: Rusty scuppers?

              "Not even NASA is stupid enough"

              Wait what? I thought we were fixing NASA's design flaws.

              Are you telling me that, bear with me here, NASA may have thought about rain when they designed these dishes?

              Say it's not so.

              Here I was ready to expose my genius level skills by denigrating those stupid engineers and scientists who have deployed the largest dishes all over the planet, and now you tell me they actual might know what they are doing?

              This keyboard warrior is so disappointed about a missed opportunity. Anyone got any suggestions for other areas I can excel in? I hear vaccines are big right now. Maybe I'll mosey on over to the immunology department and use my genius to point out their obvious errors.

          2. Spherical Cow Silver badge

            Re: Rusty scuppers?

            "Canberra doesn't get much frost (if any at all - normally it barely touches freezing during winter) - more importantly it doesn't get much rain when it's that cold and it doesn't get much in the way of high winds either"

            I live in Canberra. We get LOTS of frosty nights every winter, some as low as -8C. We also get severe thunderstorms (like the one yesterday which filled up the dish and flooded my back yard) which bring torrential rain and very high winds.

            1. VerySlowData
              Thumb Up

              Re: Rusty scuppers?

              long ago, I also lived in Canberra and experienced torrential rain storms that flooded and closed main roads in the south (Woden Valley). Once such event caused cars to be swept away with at least one fatality.

              The frost: removing the ice from your windscreen is a regular morning chore in Canberra...

      2. Anonymous Coward Silver badge
        Boffin

        Re: Rusty scuppers?

        Surely it just depends on the wavelength of the signals you intend to use? In the same way as microwave oven doors have holes in the shield so you can see the food, but the holes are sized to not allow the microwaves to escape.

        OK, that might make the drainage inefficient and prone to blockage, in which case a small pump might prove useful. Keep the 'pause operations and tip the dish' procedure as a reserve in case the pump fails.

  2. Denarius

    monsoonal ?

    Even better, a full bore La Nina with a monsoon trough further south that usual. Not as much as 1974, but some of the recent local storms are worthy of a Top End Wet. On the bright side, it is safe to slash the deep grasses except for the risks of bogging.

    1. Anonymous Coward
      Anonymous Coward

      Re: monsoonal ?

      Maybe that should be moonsoonal?

  3. Neil Barnes Silver badge
    Coat

    "How do you clean the dishes?"

    In a nice energy efficient dishwasher, thanks. You?

    1. Gene Cash Silver badge

      Re: "How do you clean the dishes?"

      Energy efficient dishwasher? No, I much prefer one that actually gets the dishes clean without having to run it twice.

      1. jake Silver badge

        Re: "How do you clean the dishes?"

        Same for supposed energy efficient clothes washers. And dryers. As for so-called "low flush toilets" ... and don't get me started on "spill-proof" gas (petrol) cans ... Etc. etc. etc.

  4. Potemkine! Silver badge

    Being able to listen to a probe 19 billion kilometres from Earth which probably emits a signal with a power lower than one from a cellphone is absolutely astonishing.

    Congrats to all involved in the performance.

    1. Martin an gof Silver badge

      Oddly I can't find the info on the NASA or JPL Voyager websites, but How Stuff Works claims that the main transmitters use 23 Watts, which is quite a bit more than the maximum power of a cellphone, but still, not really a lot!

      M.

      1. Tom 7

        Its coming from a high gain antenna which is pretty good when pointing in the right direction.

  5. Craig 2

    160 bits per second...

    They can manage 19 billion km! My wifi feels slower than that when I go to the shed at the bottom of the garden....

    1. Androgynous Cow Herd

      Re: 160 bits per second...

      Like many before you - you hear "Bandwidth" but don't consider "Latency"

      299,792,458 m / s. - It's to just a good idea...IT"S THE LAW!

      1. jake Silver badge

        Re: 160 bits per second...

        "Never underestimate the bandwidth capability of a station wagon full of mag tape." is a quote often attributed to Tanenbaum in 1996, but it was a common expression when I was at DEC long before that ... and I remember a similar comment from a student at Stanford in the early '80s when a professor expressed surprise at one of the vaxen already running the latest BSD build, released just a few hours before. Conversation went "How on earth did you get that code across the network that fast?" answer was "My motorcycle's latency might be sub-par, but it still has a much higher bandwidth capability than your network!".

    2. Tom 7

      Re: 160 bits per second...

      I wonder if they use a phone stuck into an acoustic coupler like what we did in the early 80s? Always used to amaze me how much info you could actual send/receive over a 70/300 modem. Used to send small circuits to an IBM somewhere and get reams of line printer plots to check over the next day!

      1. jake Silver badge

        Re: 160 bits per second...

        I'm pretty sure you're joking, but the answer is no. In fact, the extremely weak signal from nineteen and a half billion miles away (three quarters of a light-day) is pulled out of background noise by some very clever equipment and programming.

        In the other direction, we can broadcast at pretty good power, so the Voyagers receive a clear signal.

    3. Trigonoceps occipitalis

      Re: 160 bits per second...

      Hand speed Morse (@ 25 WPM) is about 700 bps - still a bloody good show.

  6. andy 103
    Pint

    Mind boggling

    The numbers with either Voyager craft have always seemed mind boggling to me.

    It's hard to visualise how far 19 billion km is or even how much has occurred on Earth since the crafts were launched. Or a speed of 15 km/sec meaning I could get to my office in under 3 seconds. Hard to imagine.

    The fact a comms link is even possible is astonishing. Yet it also beggars belief we can't connect certain people on Earth given this is actually possible so far away from it.

    1. Stoneshop
      Boffin

      Re: Mind boggling

      It's hard to visualise how far 19 billion km is

      Some 480000 times the circumference of the Earth at the equator. Going around 13 times _a day_ it would take you 100 years to cover those 19 billion km.

      Or a speed of 15 km/sec meaning I could get to my office in under 3 seconds.

      At that speed I don't think you'll be Gatso-ed, at least not with your license plate sufficiently unblurry, but you do have to start braking in time so as to not smash in to the wall at the far end of the parking lot.

    2. jake Silver badge

      Re: Mind boggling

      "It's hard to visualise how far 19 billion km is"

      Here's a bit of a visual aid ... it only goes out 5.9 billion km, though. Extrapolate :-)

      1. Trigonoceps occipitalis

        Re: Mind boggling

        “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”

        Douglas Adams

    3. Boris the Cockroach Silver badge
      Mushroom

      Re: Mind boggling

      At 15km/sec getting to your office would indeed take 3 seconds

      Sadly (and taking that you're around sea level) that speed in the atmosphere at that height would cause quite a large explosion..... maybe a few melted bits of the engine would land on your desk.... but I would'nt think so.

      Still might provide a few headlines "Man attempts hypersonic commute to work... physics says no"

  7. Wanting more

    Wouldn't work in England

    The dish would spend most of the time being tipped up!

    1. Giles C Silver badge

      Re: Wouldn't work in England

      Well you could put in Dungeness which is the UKs only desert, although a nuclear power station next door might impair performance somewhat….

      1. JDPower666

        Re: Wouldn't work in England

        Although it might be claimed by the local tourist Centre, Dungeness is not a desert, it fits none of the criteria for being so.

    2. Death Boffin
      Boffin

      Re: Wouldn't work in England

      You might have noticed that the Deep Space Network dishes tend to be in rather dry places. Australia, Spain, and the Mojave desert. In the Mojave, there are many years where they get less than an inch of rain for the entire year.

      1. Anonymous Coward Silver badge
        Boffin

        Re: Wouldn't work in England

        Primarily, I believe, because the clouds get in the way of (or distort) the signals rather than because of the effects of precipitation.

      2. jake Silver badge

        Re: Wouldn't work in England

        Madrid isn't exactly in a desert. The Canberra site, with its 22 inches of rain per year, looks like a tropical paradise compared to Goldstone. (And of course the "emergency" Stanford Dish is hardly in a desert, although we are in a bit of a drought.)

    3. ThatOne Silver badge

      Re: Wouldn't work in England

      > The dish would spend most of the time being tipped up!

      Turn it completely over and you'll have a fine umbrella...

    4. jake Silver badge

      Re: Wouldn't work in England

      Have you seen the number of "golf balls" dotted around the British Isles? Why do you suppose they exist?

      1. Trigonoceps occipitalis

        Re: Wouldn't work in England

        If I told you I would have to shoot you.

  8. Sleep deprived
    Happy

    Reminds me of an old TSR program

    At random intervals, an alarm would pop up, warning that water had been detected in the hard drive and that it had to be spun faster to drain it, followed by a fast spin noise. A fast spin could indeed kick the water over the dish...

    1. Down not across

      Re: Reminds me of an old TSR program

      Reminds me of DRAIN.COM, which did the same thing (but as I recall did not TSR) and at the end did spin cycle which spun the floppy, I used it with cleaning diskettes (remember those?) to clean the heads on occasion.

  9. MrBanana

    When satellite dishes go bad

    Had to wait for half way through the video, but there it was. A satellite dish having a wee.

  10. spireite Silver badge
    Coat

    They had to plan up front, by planning the days on a colander

    1. jake Silver badge

      I'll bet coming up with that was a real strain.

  11. Anonymous Coward
    Anonymous Coward

    I would love to drag one of the "5G RF Brain Damage!!!" type "individuals" to that place and let them know just how much stronger the signal is there. :)

    1. jake Silver badge

      You mispleled "Drain Bramage"[0] and "induhviduals".

      [0] Given the context, how could it not be?

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