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Starlink v2 reached the brightness reduction target recommended by astronomers
- whinvik 3y agoI didn't quite understand what this meant from the headline. The introduction in the paper clears it up. The TLDR is that astronomers are concerned they won't be able to do space observations with so many satellites in the way, but SpaceX has optimized for some parameter the indicates this will not be an issue.
- georgeg23 3y agoThe black paint also makes for stealthier capability in SpaceX's military satellites https://wikipedia.org/wiki/Starlink#Military_capabilities https://wikipedia.org/wiki/Starlink#Military_capabilities
- wazer5 3y agoGuess they take "black projects" seriously!
- George83728 3y agoThere's an interesting question concerning why (most) US stealth aircraft are black. Black isn't the best color to make an aircraft invisible at night; a dark blueish gray is best for that. One possibility is that the radar absorbent material is inherently black so they don't have a choice, and indeed the U-2 was originally a dark blue color before it received a new black RAM paint. That is probably the real reason I think, but another possibility is that when missile and radar technology made visual intercepts less relevant, they were freed to paint these secretive aircraft a less optimal black, which everybody knows is the proper color for secretive aircraft. Incidentally the new B-21 apparently won't be black. Maybe they have a new RAM paint formulation that doesn't force the choice of black.
- Tommstein 3y agoWhatchu talkin' 'bout Willis? Neither the B-2, nor the F-22, nor the F-35 are black, they're all this bluish gray you mention, same as most non-stealth aircraft. The only stealth aircraft I can think of that was black was the F-117.
- George83728 3y agoYou're right that the F-22 and F-35 aren't black, but neither are they the blueish gray I'm talking about which is much darker: https://dragonladyhistory.com/2019/04/30/u-2-black-paint/ https://dragonladyhistory.com/2019/04/30/u-2-black-paint/ The B-2 also isn't very blueish, it's more on the dark gray end of the scale but I can see how that's subjective. And you're forgetting the U-2 and SR-71, which lacked full blown RCS reduction geometry but were still fitted with the black RAM coating (the SR-71 also had some stealth geometry; that was the purpose of the chines.)
- philwelch 3y agoThere's no stealth in space. Any sort of running electronics or photovoltaics will emit heat that can be easily picked up by spaceborne sensors. The strategic advantage for military satellites is going to be the fact that Starship can launch literal orders of magnitude more of them than the launch systems of rival countries, not the fact that they're painted black and thus marginally harder to spot from the ground with Mk. I Eyeball.
- georgeg23 3y agoIs there a good reference on tracking satellites from their thermal signature? Couldn't find anything.
- philwelch 3y agoThis is the most comprehensive debunking I’ve seen of the “stealth in space” concept: http://www.projectrho.com/public_html/rocket/spacewardetect.php#nostealth http://www.projectrho.com/public_html/rocket/spacewardetect.... This is one of the classic online nerd arguments, much of which is documented there. I’m a little terrified of reigniting the whole thing here and now to be honest, but if people want to get into it, have fun.
- George83728 3y agoSBIRS is intended to use infrared to track ballistic missiles through all stages of flight, including decoys and debris released during the mid-course phase in space (so we know it's meant to be extremely sensitive, not limited to tracking hot rocket engines during the boost phase) Seems like a good bet that orbital systems with such sensors could be used to track LEO satellites too.
- bee_rider 3y agoThat’s weird, every ork knows purple paint makes it stealthy.
- teamonkey 3y agoThese will be still easily bright enough to be seen through a light pair of binoculars, so the claim that they won’t interfere with astronomical observations is a real stretch. The problem with Starlink vs other satellites isn’t just the individual brightness but the vast number of them, and that they are often visible in a swarm.
- itomato 3y ago[flagged]
- abletonlive 3y agoI know reddit is experiencing some sort of mod-led black out right now but does that mean the kind of content that you'd find there need to make its way here? This is hackernews. We celebrate progress.
- tiahura 3y ago[flagged]
- hef19898 3y agoNah, eternal praise of Elon's engineeting super powers for the next ten odd years will do.
- barelyauser 3y ago[flagged]
- m2fkxy 3y ago[flagged]
- clnq 3y agoWell, both can be achieved.
- philwelch 3y agoNot only can both of those be achieved, the ability to launch so many satellites means we can observe those distant stars from space, which gets around the much bigger problems of Earth's atmosphere and light pollution.
- zulban 3y agoThis isn't a war. We can have both. If no effort is put in to make everyone happy, that's bad, so it's good they're working on these light issues.
- barelyauser 3y agoI've been to Africa and seen the real world impacts of the lack of communications. I'm against anything that stands in the way of solving that specific problem. Astronomers come second to that, plain and simple.
- George83728 3y agoI guess you missed this recent news story: Starlink v2 reached the brightness reduction target recommended by astronomers So we can now have both. Africans can have their satellite internet, and astronomers can see their dwarf stars. Both should be satisfied so what are you so bitter about?
- HideousKojima 3y agoFunnily enough, I saw a train of Starlink sats from their most recent launch (which was Sunday I think?) on Tuesday night in the skies over northern Utah. I assume this reduction is for normal nighttime hours, and not the times immediately after sunset/before sunrise when they can catch the light while still ascending to their final orbit? Edit: the launch was early in the morning on Monday
- hughes 3y agoIt’s for their operational orbit. During deployment and orbit raising (while you can see the train) they won’t necessarily be in stealth mode yet.
- jccooper 3y agoStarlink brightness concerns are mostly for around dawn and dusk. During the night, since they're pretty low, they're mostly in complete shadow. However, the darkness design is for operational altitude and attitude; during orbit raising, they are in an unusual mode.
- clnq 3y agoIt's good that these expectations are set, and even better that they are met. We'll probably have more constellations of satellites in the future, so it's good that there are clear goals to hit to limit their negative effects.
- deleted 3y ago[deleted]
- beardyw 3y agoCan someone explain to me how the title as it appears here relates to the linked paper. "Therefore, the Mini satellites are fainter than Gen 1 Starlink satellites despite their larger sizes. " OK, but no mention of "the brightness reduction target recommended by astronomers" anywhere. If there is a missing source please can we see it?
- NelsonMinar 3y agoIt seems like the wrong title. I couldn't find any support for it in the paper. The paper does say 'Their goal is to “make its second-generation satellites invisible to the naked eye when they are on station”.' Which to me sounds like "make it so ordinary folks don't notice" and has very little to do with astronomy. It's a nice improvement but doesn't solve the problems. Edit linked elsewhere in the discussion: https://cps.iau.org/news/nsf-and-spacex-sign-agreement-to-mitigate-impact-of-starlink-satellites-on-ground-based-astronomy/ https://cps.iau.org/news/nsf-and-spacex-sign-agreement-to-mi...
- bilsbie 3y agoThey talk it about that on the reddit thread https://pay.reddit.com/r/spacex/comments/14bhto5/observation_shows_starlink_v2_mini_in_brightness/ https://pay.reddit.com/r/spacex/comments/14bhto5/observation...
- seltzered_ 3y agoBrightness reduction is nice but it's still important to also consider the energy required to keep starlink running: https://twitter.com/rdrimmel/status/1563158073694310401 https://twitter.com/rdrimmel/status/1563158073694310401
- Trufa 3y agoThis comment is the most egregious case of whataboutism I've seen in a while.
- EA-3167 3y agoWhataboutism refers to a Soviet-era habit of rhetorical distraction, i.e. "The USSR does something terrible," to which the reply was, "Whatabout the terrible things the US does?" How does the comment you're referring to add up to that?
- Trufa 3y agoLight pollution is fixed ,but WHAT ABOUT co2 is what I meant.
- EA-3167 3y agoThat's... not whataboutism, it isn't an attempt to distract from an accusation or problem, it's the opposite of that in fact.
- Trufa 3y agoI honestly don't get your point, you probably misunderstand me, we might disagree, but this is not the opposite case of whataboutism. This advancement is objectively good, it's one of the issues raised later in the twitter thread even, and (s)he chooses to change the focus to another subject.
- yc-kraln 3y ago
- temptemptemp111 3y ago[dead]
- jwuphysics 3y agoPlease don't editorialize the title. The title is > Starlink Generation 2 Mini Satellites: Photometric Characterization I'm a professional astronomer and I don't know what the "brightness reduction target recommended by astronomers" is. I do know that a 7th magnitude source will likely saturate most large research telescopes, rendering a good chunk of that data useless.
- varelse 3y ago[dead]
- bilsbie 3y agoI don’t normally change it but in this case it seemed too esoteric. People wouldn’t know why they should be interested.
- Waterluvian 3y agoCould you link to where this claim is made? I don’t see it in the article.
- bilsbie 3y agohttps://pay.reddit.com/r/spacex/comments/14bhto5/observation_shows_starlink_v2_mini_in_brightness/ https://pay.reddit.com/r/spacex/comments/14bhto5/observation...
- deely3 3y agoBut title is incorrect?
- sieabahlpark 3y ago[dead]
- TigeriusKirk 3y agoHere's a link to the IAU website about an agreement between the NSF and SpaceX to set a target of below 7.0 magnitude for Starlink. https://cps.iau.org/news/nsf-and-spacex-sign-agreement-to-mitigate-impact-of-starlink-satellites-on-ground-based-astronomy/ https://cps.iau.org/news/nsf-and-spacex-sign-agreement-to-mi...
- slashdev 3y agoMy parents recently got starlink internet in a developing country with measured 70mbits down and 12mbits up. It costs about the same as wired internet, which is available where they live. But the speed is higher and they can run it on a battery so the internet stays up even when the power goes down, which happens often. I think it’s a game changer for people in rural areas and cabins, people in RVs, people on boats, etc. I’ve worked remote my whole career, but now it is possible for me to do that from anywhere on earth with starlink service. That’s amazing to me.
- nroets 3y agoI'm guessing it will also make airline passengers more productive.
- pythonguython 3y agoI have what might be a controversial opinion. Sacrificing terrestrial visible light astronomy for a well developed worldwide satellite communication constellation seems like an easy trade. Astronomers can still do terrestrial radio astronomy, and as far as I know, it seems like the utility of orbiting telescopes far outweigh the utility of terrestrial telescopes.
- some_random 3y agoYeah I tend to agree. My opinions on the internet in general have soured greatly in the last few years, but even still enabling things like telehealth to rural areas seems like an overall win.