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Broadband Expansion Could Trigger Dangerous Surge In Space Junk (theguardian.com)
A new study from the University of Southampton warns that expanding broadband networks via launching "mega constellations" of thousands of communications satellites could increase catastrophic crashes of dangerous space junk in Earth's orbit. "Dr Hugh Lewis, a senior lecturer in aerospace engineering at the University of Southampton, ran a 200-year simulation to assess the possible consequences of such a rise in orbital traffic," reports The Guardian. "He found it could create a 50% increase in the number of catastrophic collisions between satellites." From the report: Such crashes would probably lead to a further increase in the amount of space junk in orbit, he said, leading to the possibility of further collisions and potential damage to the services the satellites were intended to provide. The European Space Agency, which funded Lewis's research, is calling for the satellites planned for orbital mega-constellations to be able to move to low altitudes once their missions are over so they burn up in Earth's atmosphere. They must also be able discharge all batteries, fuel tanks and pressure tanks to prevent explosions that would scatter debris. Lewis is presenting his research this week at the European conference on space debris at the ESA's center in Darmsadt, Germany. Krag said he expected some of the companies planning launches to attend.
What we're really finding out here is that we need to build an orbital cleanup satellite. I know that nets have been suggested but considering the speeds we're dealing with in orbit (about 17K mph), it seems like a beaded door curtain would be able to handle the stress and be able to catch small pieces. Naturally, each strand of the "curtain" would need to be exceptionally strong, perhaps something like woven carbon nanotubes.
However it's designed, we need to build something to clean up our space junk that can withstand sizable differences in velocity.
Anons need not reply. Questions end with a question mark.
A "low-cost" device sent into LEO? So it's being sold on the admittedly astonishingly low cost compared to traditional launch costs.
So any additional costs (such as end-of-life mechanisms designed to put it into a burn trajectory) are going to have a proportionally greater impact on that "low cost" selling point, which means the proponents have a motive to resist such extra mechanisms and costs.
Anything sold on its main benefit being "low cost" will eventually result in a race to the bottom, and the cost-cutting that entails - "hey, our module is lighter and cheaper to get into orbit (because we decided to do without expensive impact shielding/temperature control/whatever)"
They sentenced me to twenty years of boredom
A simple solution would be for such satellites to be restricted to orbits with a short expected lifetime.
... to pollute every enviroment it can access. We've done a nice job messing up our atmosphere, the land and sea so the next frontier naturally is space. Who cares if ultimately all this microsatellite crap put up by here today, gone tommorow startups will hang about for decades and cause endless future problems for serious satellites in the future? Profit matters and it matters NOW! Hang any other considerations, right?
With all the space junk, and polar rivers flowing backwards, and Al Gore jetting around in his private aircraft, and Muslim maniacs, and Elizabeth Warren, and alligators on golf courses. I'm going back to sleep.
Ah OK, so when the thing is worn-out and obsolete you propose to...recycle it somewhere, like on the ISS?
You know that one person-day of work in LEO costs MINIMUM 7.5 million bucks, right?
https://en.wikipedia.org/wiki/...
That buys you a fuckton of cubesats & launches, space cadet.
How about we just use fiber instead?
Besides standards, there are probably a lot of technical and economical issues to deal with if you take an incremental approach ("working towards"). Having factories up there for recycling old satellites isn't enough, you will also need to somehow bring those satellites to one of the factories (or bring the factory to the satellite), which isn't free. Now suppose we've gotten to the point where we're able to recycle some less complex components, like solar panels, radiators, etc. Now you can build and launch your satellites without those and have them added in an orbital factory. Even assuming this gives a benefit in launch costs and doesn't add costs due to more complex engineering or the transfer to the orbital factory, you'd still need to move the sat from the factory to its intended orbit. With all that, it sounds a hell of a lot simpler and cheaper to add a de-orbiting mechanism to each satellite.
Maybe it'll be viable if we could improve recycling and manufacturing to the point where we could build a satellite "containers" in orbit: a standardized structure, solar panels, wiring for power, plumbing for heat management, perhaps some shielding. These could be relatively large and weak since they never have to go through launch. Operators would then launch only the functional guts and plug them into a container of the right size once in orbit. Technical challenges aside, I'd like to know if this would at all make economic sense (would you save 90% of payload weight or 10% or what?)
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
This is really going full on glass half empty and it's wrong to single out communications. We are at the point where we are increasing our usage of space resources for all kinds of things. That means there's going to be more stuff up there from everything. It's a sign progress. Who knows the stuff might be able to be harvested and reused in orbit.
The whole concept recycling old satellites is beyond crazy. All you get is a bunch of worn old scrap for insane cost. And a factory still needs raw materials, so you save nothing in launch costs.
High orbit sats are indeed high lag. Low orbit sat constellations aren't quite so bad and have the advantage of automatically re-entering the atmosphere after a few years, rendering the professors fears of "Not being able to reliably perform an end of life manoeuvre" moot.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
Where do you propose to find the Delta V to safely recover all these sats, hmmm?
They're not a couple escaped helium ballons from for birthday trapped on your ceiling waiting to be grabbed, they're flying about faster than bullets in differing and often completely opposing orbits and there is no Neo from the Matrix around to wave his hand and make them all magically stop for you.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
Only retarded capitalists deny something that can save money due secondary reasons.
You're ignoring that it's not the same capitalist who will pay the cost. https://en.wikipedia.org/wiki/Externality
If I launch a satellite in a cheap 'junk-heavy' way, it's not me who it harms.
Out to geosyc it certainly is. LEO, however, is anywhere from thirty to over two hundred times closer to the Earth's surface.
Scientists need to invent a space vacuum cleaner.....
I think we need to teach that orbit is a condition, not a place.
Space Nutters think that space factories are a real thing. Just factories. But in Space.
Now I know it's a *horror* for your standard capitalist these days, but what about, like, PLANNING (omfg, he's said the *P* word!) a bit ahead?
How do you propose to "plan"? We don't have any use for recycled materials in orbit. There's a lot of infrastructure that would need to be in place first before it makes sense to recycle.
Think about some standards which would make those things as recyclable as possible (like trying to keep a set of agreed-upon materials, standards for easy deconstructibility -- all things which, you know, *might* help us down here too), working towards a LEO factory of the future?
Let us note that those sorts of recycling standards routinely create a big mess on Earth, including lower quality electronics (such as tin whiskers) and more effort spent recycling than would be saved in materials. I don't see the point of having expensive satellites follow some recycling standard that isn't justified, lowers the effective lifespan of the satellite, and won't actually be useful for decades until someone gets around to putting the necessary recycling infrastructure in space (by the time they do, they probably will be able to handle most of the current satellites and large space debris aside from nuclear reactors).
mentioned in the summary...you don't expect me to actually read the article, do you?
Geocentrists that believed the Earth was the center of the universe were popular once. A few hundred years later, not so much. I personally hope that my descendants will live & work in space but that doesn't mean I do.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
Unlikely. Launch capability is quite a step from ORBITAL launch capability. We have had solid-fuel rockets (gunpowder based) since the 13th century. We didn't get to liquid fueled rockets until 1926. From there to the first manmade objects to reach space were German V2 rockets during world war 2 - twenty years later. It took another twenty years for Sputnik 1 to become the first manmade object to actually get into orbit (and it only stayed there a few months). The oldest object in space is Vanguard 1 which was the first truly high-orbit satelite launched in 1964.
The sputnik 1 level tech couldn't do much serious harm - it just wasn't high enough (it's apoaps was over 900km but it's periapse was barely out of atmo). The satelites you want to harm are a lot higher up - and you want to maximize collisions so you want to blow up your bag of dirt and nails near them - in a circular orbit for maximum intersects. Indeed hitting anything in space on purpose seriously hard - but sending a bunch of random junk flying around hoping to hit some satellites may be feasible.
But to get from V2 to Sputnik1 and Explorer/Vanguard era satelites in 20 years - took many of the best minds in physics, chemistry and engineering in the world - which the US and Russia had at the time. North Korea does not have many such minds - their oppressive system and academic control also greatly reduces their ability to produce good scientists, their weak economy harms their manufacturing capacity...
And sputnik and vanguard had payloads of a few kilograms - to do real damage you want to take a LOT of junk - so at least a few tonnes. So you need a launch vehicle at least on par with later model Soviet R7's or the US's Mercury or Saturn Launch Vehicles.
Right now - North Korea has only once managed to put something into orbit. They claim a polar orbit with a period of 94 minutes - if we believe them that would mean they can just about put a small satellite where Sputnik 1 had it's periapsis. And they cannot do that reliably - North Korean rockets have tended to fail more often than succeed.
So could this conceivably happen ? Sure, but it seems unlikely - for the same advances that you need to achieve this, you could build highly effective ICBMS which make great propaganda television - and this, I think, is why NK has been focusing on the latter (which they don't seem likely to actually achieve any time soon).
Unicode killed the ASCII-art *
Of course, it will be you — if there is enough of it left to hurt somebody on Earth upon falling, that's enough to determine, who launched it. Reckless Endangerment is a crime. Criminal and civil penalties will soon follow.
Unless, of course, it was launched by a government organization, which is immune to prosecution. Figure that into your KKKapitali$t-bashing next time...
In Soviet Washington the swamp drains you.
Yeah, because the market is so good at stopping pollution, right? We can't even clean up oil spills or prevent oil companies from not caring if they happen. That stuff spills all the time and just hangs around for decades and poisons the soil and water. Here's our record of oil spills to date, most of which haven't received the same kind of media attention that the Deepwater Horizon did: https://en.wikipedia.org/wiki/... What makes you think "the market" will have any effect on deterring or cleaning up space junk, which is orders of magnitude more expensive and difficult?
It could be free, if time isn't much of a factor - you could use radiation thrust for example, so you don't need to burn fuel to get to where you're going. It's slow as all hell - but it works, hell some satelites like Voyager used radiation thrust as a primary station-keeping tool.
Unicode killed the ASCII-art *
Educated people know better than to try and drink salt water.
Unicode killed the ASCII-art *
North Korea is currently suborbital launch, also it is expensive. The key here is between companies like spacex and satellite miniturisation are getting launch costs down to the point where it would be feasible having lots of low earth orbit satellites rather than a dozen in geosynchronous orbit. LEO comments gives better latency but one needs a lot more as you need multiple in the sky at any time as they are constantly moving relative to the user. Before now such constellations have been the work of large governments or groups of governments in global positioning systems.
They're not a couple escaped helium ballons from for birthday trapped on your ceiling waiting to be grabbed, they're flying about faster than bullets in differing and often completely opposing orbits and there is no Neo from the Matrix around to wave his hand and make them all magically stop for you.
We've had our eye on you. We thought you might be the one, but we can see that you're not ready yet.
"Satellite Internet" does not and should not count as "high-speed Internet."
For one, high-speed Internet combines both raw bandwidth and low latency.
If you were to count Satellite internet, it would entirely discount the importance of latency, and also discount the importance of upload speeds.
So just how much damage would it cause if a certain unpopular nation with launch capability lofted a few tonnes of grit and ball bearings into orbit, packed around some high explosives, and set it off?
Sounds like the whole plot of Gravity.
The new satellite constellations will be in low orbits, and there will be a lot of satellites, allowing both high speed and low latency. Whether they will sell high bandwidth for a reasonable price remains to be seen, of course.
Yeah, geosynchronous satellites are way out there at about 6 Earth radii with 700ms ping times.
We're talking about all of the new low earth orbit mesh networks, though, that SpaceX and Facebook and Google and Virgin Atlantic have all expressed interest in launching, either as part of the Iridium 2 constellation or in competition with it.
Here's a visualization I've made of SpaceX's proposed 4000+ node constellation based on mission parameters that Elon Musk has announced publicly:
https://youtu.be/neLPRMrhy80
Imagine trying to clear a comfortable launch window through that!
Not sure if he's really serious about it, or if it's just a bargaining chip to get better negotiations for the Iridium 2 launches. But the factory for these things is just down the road across town, so I suppose I could go check.
The Fsck'n companies can't even expand manage and compete in their terrestrial areas, there is no way they should be allowed access to orbit. The lag associated with satellite internet access is awful. Why should we let them have access and compete with Hughes net when they won't compete with their land bound opposition. Screw AT&T, Spectrum, Rogers, and Shaw.
errr....umm...*whooosh* *whoosh* Is this thing on ?
Oh stop procrastinating & gimme the red pill already
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
And I just used up my mod points. Too bad. I mean, sure, the visualization doesn't necessarily give an idea of how difficult it would be to launch (the width of one of the dots looks to be approximately the same as the Paris metropolitan area, and I'm guessing the altitudes can be offset by enough to ensure that even if the dots appear to be in the same place at the same time that they don't collide).
I've just never seen 4000 things orbiting earth before, and the illustration of the flight paths shows that it's not nearly as chaotic as I expected. So thanks. I guess my take-home message (that it's not as bad as expected) may not match what you were trying to show, but I still found it neat.
"Nothing shocks me. I'm a scientist." -Indiana Jones
One data point: the satellite network proposed by SpaceX will use altitudes ranging from 715 miles to 823 miles. The altitude of a geostationary satellite is 22,236 miles. In both cases the path to the satellite is somewhat longer because the satellite is almost certain not to be directly over you. (If you're in the continental US a geostationary satellite will NEVER be directly overhead even if you're at the correct longitude because all the land is above the Tropic of Cancer. The SpaceX satellites might briefly be directly overhead.
The round trip path to a SpaceX satellite might be as long as 2,000 miles if the satellite is far from being directly over you. That's the worst case, because beyond that point there will be another one that is closer. That distance would add about 11 milliseconds to your ping time. In the ideal case when the satellite is directly overhead, the delay falls to 8 milliseconds. There is also some store and forward delay but that's true every time your packets go through an additional hop. The LEO lag is not zero but it's not terrible either.
In contrast, the round trip path to a geostationary satellite is at LEAST 44,500 miles; that path would add a quarter of a second to your ping time. Your actual path will be a bit longer because the satellite is not at the same longitude and latitude as you, but it doesn't make a huge difference to the numbers. That is more than 20 times worse than the path through an low earth orbit satellite.
Space is big. Mind-bogglingly big. You may think it's a long way to your....
Anyway, the satellites you'd want to recycle are a very few satellites in a large volume of space. There's no single place where they hang around, ready to be harvested. There's billions and billions of cubic miles in LEO space, and maybe a million objects larger than two millimeters. That's thousands of cubic miles per fleck. It's probably going to be more concentrated near the lower part of LEO, but it's still incredibly sparse.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes