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Space Communications Science

Elon Musk Says SpaceX Took 'Key Steps' To Reduce Starlink Satellites' Brightness (livescience.com) 50

"SpaceX's Starlink internet satellites will soon sport an accessory to tamp down their surprising brightness," reports Live Science: That brightness worries many astronomers, who say that the huge Starlink constellation could seriously disrupt a variety of scientific observations. And Starlink will indeed be huge, if all goes according to SpaceX's plan: The company has approval to launch 12,000 craft to low Earth orbit (LEO) and has applied for permission to loft 30,000 more. (For perspective, humanity has launched just 9,400 objects to orbit since the dawn of the space age in 1957).

SpaceX founder and CEO Elon Musk has said that the company will find a way to make Starlink craft fade from scientists' sight, predicting that the constellation will end up having no impact whatsoever on astronomical discoveries. SpaceX has been working with the astronomical community to help make this happen, researchers say, and the company has already tried out some mitigation measures. For example, one of the 60 Starlink satellites that launched atop a Falcon 9 rocket this past January sported an experimental coating to make it less reflective. Observations show that this "DarkSat" is considerably dimmer than its brighter Starlink cohorts, but probably not dim enough to quell most astronomers' concerns about the megaconstellation.

But SpaceX is taking additional measures as well, which brings us to the new accessory. Musk tweeted the following on Wednesday (April 22), in response to a Twitter follower who wished SpaceX luck on a 60-satellite Starlink launch that day: "Thanks! We are taking some key steps to reduce satellite brightness btw. Should be much less noticeable during orbit raise by changing solar panel angle & all sats get sunshades starting with launch 9."

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Elon Musk Says SpaceX Took 'Key Steps' To Reduce Starlink Satellites' Brightness

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  • by joe_frisch ( 1366229 ) on Sunday April 26, 2020 @01:45PM (#59993300)

    Seems only fair. They can have lots of low earth orbit satellites, and all the astronomers want in return is for them to relocate our telescopes to the far side of the moon, and provide shuttle service for people who work on them. No problem from our end.

    • by lgw ( 121541 ) on Sunday April 26, 2020 @02:16PM (#59993410) Journal

      I think that's where things will end up, in a decade or so. SpaceX is just the first of "new space", like the first factory smokestack in the pristine countryside at the start of the industrial revolution. There won't be fewer.

      Just as electrical street lighting forced observatories to remote places, the coming space industry will force them into space. But threat of that necessarily requires the capability to put large telescopes in orbit, with launch costs not being important.

      And, hey, maybe in 100 year when all new visual light telescopes are designed for orbit, JWST will finally launch!

    • by Kokuyo ( 549451 )

      Say what you will about Musk but the dude might actually do it even if it's just for the lulz.

    • They want to put radio telescopes on the far side of the moon because low-frequency radio waves penetrate through most human-scale structures. You need a massive amount of rock/dirt/metal to block the amount of radio waves being emitted by terrestrial transmitters.

      Optical telescopes (the ones impacted by Starlink) don't have that problem. You can just put a thin opaque shield around your telescope and it'll block stray visible light from mucking up your images. That's why Hubble is enclosed [nasa.gov] while groun
      • by Guspaz ( 556486 ) on Sunday April 26, 2020 @06:53PM (#59994254)

        Starlink happens to be intended as a funding mechanism for the company's attempts to drive down the cost of spaceflight to make Mars colonization practical. A side effect of that is that it also drives down the cost of putting anything else into orbit above Starlink dramatically.

        Launch is certainly not the only cost of launching telescopes, but part of the reason why existing space telescopes are so expensive is that they're so expensive to launch, so they need to be designed for long-duration deployments, potentially without servicing. If SpaceX gets their Starship flying regularly and reliably at a much lower cost of existing launch platforms, this could change how such things are done. Mass produce much cheaper space telescopes with short lifespans, replacing them as required due to extremely low launch costs. Put a whole bunch of them up there, both allowing computational multi-telescope observations, and giving significantly more observation time for more people to be able to use them.

  • After they get the whole system up the advantage SpaceX has doing lots of launches is that they could easily decide to replace some earlier satellites that were the really bright ones with the newer dimmer models.

    That probably will not happen right away but it seems like if they are spending enough effort to mitigate the problem they would also be open to replacing the older models too.

    • by psycho12345 ( 1134609 ) on Sunday April 26, 2020 @02:06PM (#59993380)
      Since it will be LEO, the older ones WILL be replaced, simply because they will deorbit for sure, they simply can't stay up there for a super long time. Though if they do get Starlink up and running in the rapid timeframe, then maybe they will do the replacement. But a certain amount of rollover will solve the problem in the long term.
      • Since it will be LEO, the older ones WILL be replaced, simply because they will deorbit for sure, they simply can't stay up there for a super long time.

        Looking around it seems like the planned operational life is around five years [reddit.com]....

        I was hoping they might replace the brightest ones before then but I guess even if not five years is not too bad.

  • by fredrated ( 639554 ) on Sunday April 26, 2020 @02:09PM (#59993386) Journal

    This crap is going to destroy that. Years ago I sailed a 31' sailboat to Hawaii. On a clear night in the middle of the ocean the sky was incredible. It had a presence, it hung over you with a weightyness, almost but not quite oppressive. It was clear why the ancients put so much stock in the sky. And it is so fixed and unchanging it is easy to see why things like comets freaked them out.
    The night sky is already screwed up by the massive city lights everywhere, this is going to be another stake in it's heart.

    • by lgw ( 121541 )

      And it is so fixed and unchanging

      Betelgeuse just winked at you. It was pretty strange though to see such a change in a constellation as prominent as Orion.

    • Yes. We should put off internet-for-all so that the 50 people with yachts get a nice view.

      • I think if you held a poll among yacht owners, most would choose global high speed internet rather than a night sky without some moving dots here and there. Starlink is only spectacular in the weeks after launch. Once they raised their orbits, they are much further apart and higher up. They may mess up some long exposure deep sky photographs but to the naked eye, the sky will be just as pretty.
      • by jeremyp ( 130771 )

        Actually, it's anybody in a remote place that wants to look at the night sky.

        Why do we need to destroy such wonder for the ego of one man? And frankly, I think clean drinking water and sanitation for all should be prioritised ahead of the cat picture delivery service.

        • > Why do we need to destroy such wonder for the ego of one man?

          Are you joking? You need to stop a second and think about it. If you still think this is about the ego of one man, then, all I can say, is that the ego is yours and the man is you.

  • But I like seeing reflections of satellite eg Iridium flares. It's kind of cool. They have orbital telscopes anyway.
    • Ground based telescopes are fantastically less expensive than orbital ones, and tend to do different jobs. It also takes far longer to develop and deploy an orbital telescope.

      There are some types of work that can only be done from space, but most is easier and far cheaper to do on the ground

      • by Guspaz ( 556486 )

        One of the reasons ground telescopes are fantastically less expensive is because of how launches currently work. Large-mass launches are very expensive and relatively uncommon. If you can dramatically reduce the cost of launch while dramatically increasing the payload to orbit, this could change the economics. Obviously ground-based telescopes will always be cheaper, but that gap could narrow significantly if you could mass-produce space telescopes with short lifespans and frequently replace them.

        It's basic

        • Maybe, but space stuff is still a lot harder.

          I work on cosmic microwave background radio telescopes, and there is a choice of high desert (Atacama), South pole (which has even better viewing) and space. Just going from Atacama to south pole is a substantial increase in cost, and there you just need an old C-130 to carry the parts and people to the base. There are space-based experiments of this type but they are rare and expensive.

          Designing something to work completely by remote control is a lot of work

          • by Guspaz ( 556486 )

            We're talking about an order of magnitude reduction in costs compared to current SpaceX pricing, perhaps reaching as high as two orders of magnitude reduction in costs compared to competing launch providers. It's not just a bit cheaper: it's dramatically cheaper. It also represents a very large increase in payload dimensions: the largest current external fairing dimension is 5.4m, while on Starship it's 9m. NASA SLS's payload fairing will be slightly larger at 10m, but then you're talking somewhere between

        • One of the reasons ground telescopes are fantastically less expensive is because of how launches currently work. Large-mass launches are very expensive and relatively uncommon. If you can dramatically reduce the cost of launch while dramatically increasing the payload to orbit, this could change the economics.

          Yep. There's also this thing where telescopes are more and more digital, multiple exposures all convoluted together to get final images. Having local WiFi will be very handy for space telescopes to get the data back down to Earth.

    • And we've moved from Space Junk to Invisible Space Junk.
  • by dhaen ( 892570 ) on Sunday April 26, 2020 @02:43PM (#59993506)
    https://www.youtube.com/watch?... [youtube.com] Shows my age...
  • Unfortunately, there are not enough darkening steps Musk can take to prevent these things from disrupting astronomy, nearly all of which is done with ground based telescopes especially for the deepest, most sensitive views of the Universe. I mention this last point as I note one poster here ignorantly dismissing this with "They have orbital telescopes anyway".

    One astronomer friend of mine ran calculations and found not even coating them with entirely with Vantablack can dim them enough not to be disruptive.

    • One astronomer friend of mine ran calculations

      Did you have them calculate how long satellites would be in frame at all compared to the amount of time they were capturing? Brightness alone is juts one component.

      The plain fact is that instruments trying to detect the barely detectable at the edge of the Universe... ...are the ones that would be in orbit anyway, because otherwise what are a few satellites moving rapidly across the sky compared to atmospheric distortion.

      In fact he seems to be following the tr

    • by Applehu Akbar ( 2968043 ) on Sunday April 26, 2020 @04:28PM (#59993854)

      Unfortunately, there are not enough darkening steps Musk can take to prevent these things from disrupting astronomy,

      This is a problem only during the time the sun is illuminating the satellites, just after sunset and before sunrise. How much observation with large scopes takes place at those times?

      • by 4im ( 181450 )

        How much observation with large scopes takes place at those times?

        Why would you limit the issue to large scopes? A lot of astronomy is being done by amateurs, with small equipment.

        Of those amateurs, many have families, kids and work, they can't stay up all night.

        All that gets ruined for the whole world because some supposedly developed countries seem incapable of building up decent telecom infrastructure, with acceptable choice from customers? Where other countries in comparable conditions are perfectly able to do it?

    • In fact he seems to be following the tradition of not even bothering to think about bad external effects on others.

      It's almost as if you know nothing at all about Elon Musk.

  • by DrXym ( 126579 ) on Sunday April 26, 2020 @05:09PM (#59993946)
    ... should start before you launch dozens of satellites into near earth orbit, not afterwards.
  • "The company has approval to launch"

    Approval by whom? I'm asking from a non US country...

  • Elon Musk Says SpaceX Took 'Key Steps' To Reduce Starlink Satellites' Brightness

    "Did you locate all of the complainers yet? Are you sure? ... Alrighty then, load up the new rocket with the special targeting de-orbit sats and launch when ready. With so many in orbit -- a few accidents are bound to happen after all."

    We have top men working on it right now. [youtube.com] (Be sure your adblocker is active.)

  • Comment removed based on user account deletion
  • Replace the GPS satellites with ones that also do Starlink, and give them more bandwidth and dishes and whatnot.

    Making them invisible will only become a nightmare when they predictably get lost by a profit-above-ALL-the-things company. They will just randomly obstruct sight for as long as they can stay up.

  • .. SpaceX will enable the "Christmas Lights" feature on the sat Starlink nodes and they will each begin flashing a random light show on their Earthside faces.

  • I wish the Starlink satellites had a cellphone-like camera module on the Earth-facing side, constantly streaming 4k 1-30fps video on the downlink. Even if they weren't space-hardened & all crapped out within a few months, it would be cool as hell. Imagine literally THOUSANDS of cameras in space streaming realtime video back to earth. They'd add maybe a gram per satellite, and would be a cool selling point for Starlink customers (since the camera on the satellite overhead would be the one you're receivin

    • You really think these all don't have cameras? Sure they do, just not for you. I'm willing to believe in that conspiracy.

      • To tell the truth, I'd be more shocked if they DIDN'T. Even if everyone told Elon they'd fail within a few weeks or months, they're just so cheap, lightweight, and tiny now, I honestly can't imagine Elon NOT telling them, "Fuck it, put a camera module on them. If they last, it'll be awesome and cool. If they fry, oh well."

        Now, imagine they put a SECOND camera on the opposite side of the satellite... facing towards the heavens. Every few minutes, have it grab a maximum-res shot and store it for up to a few d

  • The paper quoted is very clear: the change in brightness between DarkSat and a normal Starlink crap is of only 1 magnitude. As an astronomer I can indeed compute that it is a change in reflected light by about a factor 2.5. Good but clearly not enough. We are looking for measures that will make them way dimmer. Just consider this: for modern telescopes, bright objects (those that may create a problem for our instruments) have magnitudes in the range 15-25. A 20mag object is thus 12 mag fainter than a DarkSa
  • The quoted article's number of 9,400 objects confuses "in orbit" with "cumulative launched". The number of objects launched into Earth orbit since 1957 is about 22,330. This includes payloads, rocket bodies, and mission-related debris. Of those, about 9,480 are still in orbit. Also important, about 21,270 additional tracked fragments have been generated post-launch (i.e., on-orbit breakups), of which about half are still in orbit.

    They don't show the cumulative numbers, but see the "box score" near the

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