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Space junk removal is not going smoothly
- amelius 6y agoThat first picture: wouldn't that sphere deform as well?
- danuker 6y agoI would guess so (like a bullet). I suspect they placed a second ball for illustration.
- VBprogrammer 6y agoI think you are correct. The original ball is what appears like a paint splatter inside the deformed area.
- bombcar 6y agoI assume they put another sphere in the hole for the purposes of the picture.
- wavefunction 6y agoIt's probably not the aluminum sphere that was used in the impact but included for reference to allow readers to visualize the effect of impact versus the size of the debris.
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- marcinzm 6y agoAs other have said it's likely a second sphere there for illustration purposes. Also, I wonder if the original sphere would outright vaporize or melt into the block.
- verytrivial 6y agoAs other comments point out, the sphere would have immediately vaporized. Similar reason behind most impact craters being circular. Scott Manley has a nice explainer: https://www.youtube.com/watch?v=BCGWGJOUjHY https://www.youtube.com/watch?v=BCGWGJOUjHY
- coldtea 6y agoWho would have thought...
- xoa 6y agoWhile I know Scientific American is a fairly mainstream targeted and softer science publication, this >And the problem is now poised to get much worse because of the rise of satellite “mega constellations” requiring thousands of spacecraft, such as SpaceX’s Starlink, a broadband Internet network. really could have used a LOT more qualification particularly since it's become a major recent talking point. There is one ultimate sure-fire way to reduce space junk: launch stuff to very low orbits. There is still some atmosphere (varying with heating and other factors) up a long ways in "space", and it's only above 600km or so that orbital drag becomes negligible enough that lifetimes really stretch out. The ISS for example requires regular reboosts or it would decay back into the atmosphere. SpaceX focusing on economics has made it feasible to start planning constellations of comm sats that are low and very low earth orbit, with the understanding that inherently their lifetimes will be measured in single digit years. But that's ok since they can be replaced so cheaply. This is much better, not worse. Even if they go offline or got hit, the debris would have a very restricted lifetime. The media should do a better job of conveying how cheaper $/kg to LEO opens up a lot of new possibilities in what regulations are feasible and how we think about the basics of satellite design. A simple "Mega constellation bad!" is all wrong, and that's not necessarily going to be intuitive to everyone.
- phreeza 6y agoWait, how does launching stuff to low orbits reduce space junk? Edit: I think I now understand your comment. I mean sure it maybe adds less space junk than launching things into higher orbits, but it doesn't really reduce it, right?
- aftbit 6y agoThere's atmosphere up there, so it creates drag which slows the stuff down and causes it to re-enter and burn up or crash onto the planet in only a few years. Compare that to higher orbit, where there's much less drag and space junk could last centuries or more before it deorbits.
- ericbarrett 6y agoLow Earth orbit satellites drag in the fringes of the upper atmosphere a lot more, so their lifetime in space, unboosted, is typically only a few years. If your satellite dies, it's "self-cleaning." That said, an impact at this level can still spew debris into higher orbits, as the chaos of the collision can impart enough energy to some collision ejecta to change their orbit significantly. So you still don't want things bumping into each other.
- mesofile 6y agoMy hope is that the space junk problem becomes so severe that it forces all humans to realize there's no point to pursuing schemes of colonizing other planets, or even our own planet's orbital reaches, until we learn to better manage the industrial processes that take us there. Like a safety mechanism that ensures species who pollute excessively remain trapped on their own spheres and don't go spewing their shit all over the cosmos.
- tjs8rj 6y agoWhy not do both in parallel? A few decades of pausing space progress now could have a much bigger impact than later, and it’s not like space travel is so easy that we’ll suddenly wake up colonizers of the entire solar system. Did you fully mature before you went out into the world? Sometimes making relatively small mistakes is the fastest way to learn. “Move fast and break things”, but on the species scale.
- deleted 6y ago[deleted]
- adwn 6y ago> and don't go spewing their shit all over the cosmos Why? What's the downside to littering on some random asteroid? There's no ecosystem that would care – not even bacteria – nothing and nobody would mind if you drop a plastic bag on 423 Diotima. Take a step back and think about why pollution on Earth is bad, and you'll realize that "polluting" an asteroid isn't ethically wrong. Of course, that only applies as long as those asteroids are utterly devoid of life. Once there's an ecosystem, polluting becomes ethically wrong again.
- 5e20ad3b-cdda 6y ago>Take a step back and think about why pollution on Earth is bad, and you'll realize that "polluting" an asteroid isn't ethically wrong. Of course, that only applies as long as those asteroids are utterly devoid of life. Once there's an ecosystem, polluting becomes ethically wrong again. Why? There is no ecosystem on top of Everest yet people will get upset when they see what it looks like. This is an aesthetic decision, not a moral one.
- dalbasal 6y ago"And the problem is now poised to get much worse because of the rise of satellite “mega constellations” requiring thousands of spacecraft, such as SpaceX’s Starlink.. ..It takes an Iridium-Cosmos-type collision to get everyone’s attention. That’s what it boils down to.... And we’re overdue for something like that to happen." Perhaps the former is gentler, more statistical an alternative to the latter. Everybody be so cataclysmic these days.
- ryandrake 6y agoAll I had to do is play a little Kerbal Space Program to understand how difficult it would be to clean up space junk in orbit. Orbit isn't like some 3D grid where you stick a roomba up there, and have it go back and forth until you get everything. Even if you have the technology that lets you grab anything you encounter, you first have to reach something. And then burn some fuel to match its orbit. And then burn some fuel to get to the next thing. And then burn some fuel to match that thing's orbit (more than before because you are now carrying more mass around). It might be better to keep everything up there. Assuming the junk is re-usable in some way: If one day, we do manage to build some kind of industry in orbit, it will need to consume raw materials, and having all this scrap in orbit already means you saved most of the energy cost it would have taken to get all that mass up there.
- phreeza 6y agoI think the much more likely method would be a laser that heats one side of an object, causing a net propulsive effect leading to eventual deorbit. https://en.wikipedia.org/wiki/Laser_broom https://en.wikipedia.org/wiki/Laser_broom
- jcims 6y agoDirected energy approaches are the only thing that will scale IMHO. The heating approach is one way, but I believe something that could use the kinetic energy of ablative laser pulses would work for smaller objects. To get the correct retrograde velocity, however, I believe you would need an orbital platform and some ridiculous laser technology (which, when combined, tend to create political drag) I also wonder about sending focused packets of ionized gas to collide with an object and reduce its kinetic energy. If you were operating in an opposite orbit you'd have a ~35km/sec closing velocity. Then spit out small targeted puffs of krypton/xenon at 50km/s, it wouldn't take a lot to knock real energy off of the target. (Stubby pencil work says 80 femtojoules per molecule or roughly 30 micrograms of gas to reduce the velocity of a 20g bolt by 1000m/s. I think.)
- phreeza 6y ago
- chr 6y agoNetflix has the South Korean SF flick "Space Sweeper". Do read the serious article first. The film is for entertainment. Crossing Belter and cyberpunk aesthetics, mixing up human languages as you'd expect from the future, it's fun. Warning, link autoplays with sound: https://www.imdb.com/video/vi1534902553?playlistId=tt12838766&ref_=tt_pr_ov_vi https://www.imdb.com/video/vi1534902553?playlistId=tt1283876...
- tester89 6y agoThis is the premise of _Planetes_ if anyone is an anime fan here.
- aeroheim 6y agoI was just thinking this!
- albalus 6y agoSame!
- masklinn 6y ago> if anyone is an anime fan here. Or manga, it's originally a manga series before the 26-episode anime adaptation. The anime actually diverges from the manga in the latter section, because it was started before the series had ended (the manga finished serialisation in January 2004, the anime finished airing in February of the same year… and it was a 26ep full-season thing), so viewing both can be interesting in more ways than the usual watching of filler and interest in cross-media adaptation: > While the manga deals more with existential themes, and humanity's relationship with space, the anime further expands the political elements of the story.
- astrange 6y agoThe manga feels much more personal, by which I mean the author likes to put in moralistic side stories, but he's not very good at it and I couldn't figure out what the moral was supposed to be. Sometimes he also stops the story so everyone can stand around discussing Kenji Miyazawa novels.
- busterarm 6y agobomb ass opening theme song, for real.
- joshstrange 6y agoIt might be silly that it wasn't until watching this anime (and the whole premise for WHY space junk removal was/is so dangerous as shown by the show) that I fully "understood" the problem with space junk. It was good show on it's own as well but it really made the "space junk" click for me.
- readingnews 6y agoAnd after all those warnings. https://www.youtube.com/watch?v=1REkejAMnNo https://www.youtube.com/watch?v=1REkejAMnNo
- toss1 6y agoI want to know the collective mass of this 'space junk'. It is indeed unusable now, but it is a lot of highly refined matter that is already high in the earth's gravity well. The question is whether whether enough of it exists that it could become useful, or even profitable, to reuse/recycle it. Once you've gotten a herding satellite to rendezvous and dock/grab the junk, how much extra energy is needed to park it in a useful common orbital location for later reuse/recycling, vs making it new on the ground and lifting it out of the gravity well again? Seems it could be a profitably exploitable resource, if the scale is right?
- qayxc 6y agoIt's not much and it's definitely not profitable. The vast majority of space junk (by number) is small pieces of metal, bolts, specks of paint, that sort of thing. The few bigger things are rocket stages, decommissioned satellites, and larger collision fragments. The problem is that the most dangerous debris (e.g. debris that doesn't deorbit on its own anytime soon) orbits between 2000km and GEO at varying inclinations. These orbits are difficult to get to and the debris is worth nothing compared to the energy you'd have to spend to catch it. The value of the debris itself is comparable to the value of junk here on Earth. Unless space faring nations are paying for removal, I cannot see any scenario in which the ~8,000 metric tons of space debris [0] can be collected and recycled at a profit. It's just too difficult and costly to do. [0] https://trumpwhitehouse.archives.gov/wp-content/uploads/2021/01/National-Orbital-Debris-RD-Plan-2021.pdf https://trumpwhitehouse.archives.gov/wp-content/uploads/2021...
- bilekas 6y agohttp://stuffin.space/ http://stuffin.space/ For some context of the amount of 'stuff' in space.. This does include debris also. It's a serious amount. There is an incredible amount of Iridium from the mentioned collision : http://stuffin.space/?search=1999-037 http://stuffin.space/?search=1999-037
- hinkley 6y ago'Catching' a piece of space debris is really a 7-dimensional problem, isn't it? You have to be in the right place at the right time (4), but if you have the wrong velocity (+3) you just end up causing the very problem you're trying to prevent.
- andrewflnr 6y agoI think there has to be a way around this, at least for the small stuff. You ought to be able to catch flecks of paint and the like with a Whipple shield backed by a plate of steel. Or maybe the same kind of aerogel setup they use for collecting comet tails.
- hinkley 6y agoI think we have done some experiments with that already but I can’t recall what the outcomes were.
- fatiherikli 6y agoThis is amazing too
- visviva 6y ago"Not going smoothly" is weird phrasing - it's not "going" at all. It's still in the technology development phase, and meanwhile there is still insufficient consensus that more dramatic action needs to be taken. I know the article touches on these points, I am mostly just commenting on the strange headline.
- Diederich 6y agoThe following is based on the assumption that more and more stuff is going into earth orbit over time. As others have noted, putting satellites in lower orbits, below 500km or so, definitely helps with keeping things tidy. Beyond that, robust regulation about ensuring that very little or no additional non-useful stuff is placed into orbit is also good. That is, require everything that isn't useful to deorbit right away or relatively quickly, and have the ability to deorbit at EOL. What's beyond all that is the set of all things in orbits that aren't useful and that will naturally stay up there for a long time, in addition to any NEW stuff that's added, either by error or by accident. For example, a satellite in a 1000km orbit that has everything it needs to deorbit at the ends of its life, but fails to do so for whatever reason. As others have noted, matching orbits is a lot harder than most people realize. Specifically, it's quite energy intensive. At this point, basic physics tells us what we must do. In order to get long-lived, useless stuff out of orbit, we need to be able to send up specifically designed stuff, and a lot of it. In summary: the most fundamental solution to this problem is to vastly decrease the price per kg to orbit. Regulation helps, but does nothing to clean up what's already there, and to resolve the unintended addition of new junk. Summary to the summary: the newest crop of launch providers are aggressively working on this problem by aggressively pursuing reusability.
- aledalgrande 6y agoAnyone who knows stuff about this, could LEO debris become dangerous for commercial airplanes?
- mehwoot 6y agoNo. At the height airplanes fly, any debris would just be falling almost straight down, if it even makes it that far (I think most would just burn up in the atmosphere anyway). The reason debris in LEO is dangerous is because it's going really, really fast and continually orbiting for years so if there's enough of it eventually you'll run into something.
- aledalgrande 6y agoYeah that's what I'm wondering: if there's enough debris in LEO is there any danger that small/not fully burned pieces going down at high speed would pierce airplanes? I have no idea what kind of volume/probability we're talking about...
- Causality1 6y agoI'm confused by the photo. Newtonian impact depth says an impactor of equal density to the target will only penetrate to its own length. How come the aluminum ball clearly went way deeper than that?
- cratermoon 6y agoFor all the people saying that there's no issue with thing in very low orbits, I'm going to suggest considering the following issues. 1. When that busy ~500km orbit has a collision, some pieces might be kicked up to higher orbits where they pose a risk to other satellites. There's also important things in lower orbits, like ISS. 2. Every satellite that falls back to earth from any orbital altitude has to pass through very low earth orbit. Between 1 and 2, the debris is never going to be confined to low orbits where everything decays quickly.
- beardyw 6y agoI predict we will be just as successful in looking after space as we have been with the planet. So no worries.
- xyzzy21 6y agoSpace Junk has been an issue for "rocket scientists" since the 1980s. The consensus even back than was that it's really not doable simply due to physics and the volume of "space" in orbit. The only viable strategy identified was to design launched objects to re-enter and burn up. But that was only started with DOD and NASA - nothing could be assured that the USSR/Russia or China would ever do the same. And the military always kept the option to put national defense ahead of this as well. I always look in articles about space junk for any inkling of addressing the fundamental physics issues we identified back in the 1980s and I've yet to ever see those mentioned. It's always some shallowly thought-out, gee-whiz ideas by someone who's never actually worked in the field. Elon Musk-style.