Can We Use Special Sails To Bring Old Satellites Back Down To Earth? (universetoday.com) 70
There's already nearly 5,000 satellites orbiting earth, "and many of them are non-functioning space debris now, clogging up orbital paths for newer satellites," reports Universe Today. Yet over the next five years we expect to launch up to 2600 more -- which is prompting a search for solutions to "the growing problem of space debris in Low-Earth Orbit."
Some exotic-sounding solutions involve harpoons, nets, magnets, even lasers. Now NASA has given Purdue University-related startup Vestigo Aerospace money for a six month study that looks at using drag sails to de-orbit space junk, including satellites, spent rocket boosters, and other debris, safely...Drag sails are a bit different than other methods. While the harpoons, lasers, and nets proposed by various agencies are meant to deal with the space junk that's already accumulated, drag sails are designed to be built into a satellite and deployed at the end of their useful life... Once deployed, they would reduce an object's velocity and then help it deorbit safely.
Currently, satellites deorbit more or less on their own terms, and it's difficult to calculate where they may strike Earth, if they're too large to burn up on re-entry... [D]rag sails offer an affordable, and potentially easy-to-develop method to ensure future satellites don't outlive their usefulness.
The company was started by a Purdue associate professor of engineering who tells the site they're building in scalability, so their sails can handle satellites that weigh one kilogram -- or one ton.
Currently, satellites deorbit more or less on their own terms, and it's difficult to calculate where they may strike Earth, if they're too large to burn up on re-entry... [D]rag sails offer an affordable, and potentially easy-to-develop method to ensure future satellites don't outlive their usefulness.
The company was started by a Purdue associate professor of engineering who tells the site they're building in scalability, so their sails can handle satellites that weigh one kilogram -- or one ton.
5G (Score:1)
And this will get even worse with 5G, as a lot of small satellites will flood the low orbit space.
We will eventually have a harder time just getting out into space :-o
Re: 5G (Score:1)
No it won't, because that's not how any of this works.
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LOLZ, no. Those small ones will all burn up during reentry.
It's BIG junk that makes the trip down
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My concern is not the re-entry and burning up, but the actual high numbers that will flood the low orbit space, while in flight.
Similar to the general concern of small pieces from broken satellites that orbit at higher altitudes and with very high velocities, and can make huge damage to anything in its orbit.
Re:5G (Score:5, Insightful)
The problem with "space debris" is not satellites. Those are easy to track and in known orbits.
The problem is the small fragments, paint chips, loose nuts and bolts, etc.
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Sure, drag sails might work (Score:3)
But using harpoons would be way cooler.
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Why does everything have to be so expensive and destructive? Can't we just give them a push?
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Why does everything have to be so expensive and destructive?
Because we're guys.
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Of course, you then have to deal with Greenpeace and other protestors trying to blockade your hunt . . .
hawk
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That sounds somewhat like a Futurama episode [wikipedia.org]. I wonder if Free Waterfall Sr. will be protecting the satellites?
No. TFA is misleading. (Score:5, Insightful)
This only works for satellites deployed in the future which does nothing for space junk we are trying to clean up.
While the harpoons, lasers, and nets proposed by various agencies are meant to deal with the space junk that's already accumulated, drag sails are designed to be built into built into a satellite and deployed at the end of their useful life
This means this does NOTHING for old sats. Also, there is already a mandate that LEO sats have de-orbitting systems.
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He's talking about new old satellites... old satellites that, as it were, have not come to be. Of course it does nothing for old old satellites.
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I was also going to bring up the hazards of their propellant systems, both mono-and bi-propellants. Hypergolics are nothing to fool around with.
why not small rockets (Score:2)
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A sheet that can operate for months. Which gives the most delta-V: A solid fuel rocket burning for ten seconds, or a sail catching the tiny trace of atmosphere for ten months?
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It depends on the altitude. A moderately sized sail will provide a decent amount of drag in low Earth orbit. Higher orbits aren't as much of a problem since there are fewer satellites there, more space, they tend to be mostly going the same direction, and they tend to stay where you put them because there's much less drag.
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We could have special ... (Score:2)
... sales if Amazon offered them on Prime Day.
Looks too complicated (Score:4, Insightful)
I'm thinking a weather balloon, a short tether, and a CO2 cartridge would work just as well. You don't need much gas to fill the balloon at high altitude.
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How about a streamer and a spring?
An airbag is probably the most sensible thing, actually. Just don't have it made by Takata.
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You don't need much gas to fill the balloon at high altitude.
But that's got a severe problem -- which SIDE of the Earth is is going to land on? If it's the BOTTOM side, you're going to have many problems trying to retrieve it -- it's cold and dark and you'll fall off. (Downwards, that is.) Or do satellites only orbit on the sunny, top side of the flat Earth? I always get that confused.
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The Planetary Society has cobbled together a light sail that fits in a 3U cube sat. The big advantage of a sail is that any punctures don't significantly change its effectiveness.
Well, for new stuff, OK. (Score:3)
But what about all the junk that didn't get these "special sails"?
It just stays there?
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But what about all the junk that didn't get these "special sails"?
It just stays there?
If it's in LEO, then it will clean itself up.
If it isn't, then we have to do something about it ourselves.
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... eventually.
The problem is, of course, that the period from [now] to [eventually] can be a long time. But certainly, stopping adding to the problem is a good start. Unless you're a climate change denier, in which case the first step to solving the problem is a series of thermonuclear de-orbiting exercises, to turn existing satellites into rapidly dispersing clouds of debri
There are other possible solutions (Score:4, Interesting)
1) Have companies/countries pay a deorbit deposit prior to launch approval, Of course this could be made retroactive to say 1959 or so.
2) The value of junk in space is pretty high.
Raw materials that have escaped the atmosphere could be useful.
Some companies could probably bill the owners of the debris and then sell it to a solar forge set up to re-purpose it, instead of letting it burn up and be wasted.
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The problem is that it is mixed waste, to a very fine scale. If it were titanium panels, it might be one thing, but panels of titanium bolted together with stainless steel bolts, with Monel metal (because it's an awkward SOB of a metal to process) pipes transiting the plate with brass fittings ... they're a very different thing.
Yes, you could mandate more reprocessing-friendly construction methods ... for satellite
Or just require obsolescence insurance (Score:2)
...and let the market choose the best way to deal with the problem of space junk.
We could do the same for gas stations so when the underground tanks leak and make the land unsuitable for any other purpose, there would be money for remediation.
And for homes, like those in Detroit that they're tearing down because the streets are too costly to maintain. (Foundations in particular are very costly to rip out.) Maybe also along coasts where managed retreat from rising sea levels is the only sensible option. And
Hacker bait (Score:5, Interesting)
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This is different, or worse, from a hacker hacking into a satellite and corrupting its code so that it no longer works at all?
If you posit hackers will be able to take control of stuff as a basic assumption, then the entire modern world is essentially a bad idea. It may be, but not for this reason.
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Active satellites have station keeping thrusters that would be perfectly serviceable for destroying them. So how many do you hear of that happening to? Not many? Turns out it's perfectly possible to make remote access secure if you actually care about protecting your multi-hundred million dollar investment.
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Draw A Line (Score:2)
However, how many of satellites being launched in 2019 will have the ability to de-orbit at the end of their working life? I would guess that number will be depressingly small, certainly in the single-digit percent range.
So perhaps the first step in solving the bigger problem might be making sure that the problem stops getting any bigger whilst we're working on the full solution. Unfortunately, I'm not sure how we could achi
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The main issue, as you say, is compliance. I've heard (second-hand) that compliance is 30% or higher. So the first step is getting people to comply
Clearing other debris, cube sats etc... (Score:2)
If this thing puts a sail big enough to slow down and deorbit, it's going to do some inadvertent cleanup as it goes.
Use them as building materials for space project (Score:1)
Electrodynamic Tethers (Score:2)
My favored experimental method of deorbiting satellites in LEO is a form of electric propulsion that uses a tether to create drag on the Earth's ionosphere. [wikipedia.org] Much less can go wrong than with a drag sail, which, like solar sails, can fail to unfold/deploy/orient correctly. A tether is just a bare wire, much harder to screw up.
Reusable Rockets (Score:2)
i find it amazing (Score:2)
i find it amazing that in the many decades that we have been sending stuff into space, we are only starting to think about the waste problem now. god know how many more years (and many more space debris) we will have something that will actually work and be used.
just like little kids, we're all about the play and forget about the cleanup once the fun is over.