So here's a potential business model for this: salvage rights.
When ships sink, the owner generally still retains ownership of any property. Sometimes the location of the wreck is known. Sometimes it needs to be found. It can cost a lot of money to find a wreck and recover any property.
So salvage rights are a principle of maritime law such that whoever does this is entitled to a reward commensurate with the value of the goods recovered (eg 10%).
I imagine there are orbital slots that are essentially unusable because of space debris (eg Project West Ford [1]). If orbital slots are sufficiently scarce then these could have value. At some point it may become commercial to spend the effort cleaning up an orbit and making it available. Companies could then be compensated for the value they create this way.
I do believe this will still require a dramatic decrease in launch costs, as in orders of magnitude more. But we'll see.
My personal belief (and hope) is that the future of getting into orbit is orbital rings [2]. If so, that completely changes the game because cleaning up an orbit essentially becomes a problem of just holding up a giant "paddle" (for lack of a better word) that is fixed to a point on Earth (essentially) and just letting the debris hit it.
At the speeds those things whiz by, what sort of materials are there that can withstand impacts and not create more debris? Or do they try to do it via relative speeds and say let them hit the "paddle" at 50mph? And in that case, might it not be more effective to have hunting "nets" to collect the objects?
First, a lot of space debris is small. I'm talking like flecks of paint. That's an issue at high speed and this has hit the ISS [1].
Obviously there's the conservation of momentum to deal with. That fleck of paint has a decent amount of momentum but that's fairly easily absorbed by a couple of tons of material fixed to an otherwise rigid body.
You'd probably attach it via cables and if, somehow, enough momentum was delivered to that "paddle" that it would tear off the cables would just let it go.
If the paddle is fixed to the ring and is let go, it's just going to fall to Earth even with any added momentum, in which case it'll burn up in the atmosphere.
The more dangerous debris is larger stuff. Like there are dead parts of rockets, even smaller stuff like bolts. These pose extra challenges but a lot of the same principles apply.
Maybe not hunting nets per say, maybe just a huge trawling net, or some sort of trawling-foam since we're in space. As high velocity objects begin to hit it, the foam will gain speed, but overtime, with presumably random speed-object collisions, the foam and its captured contents should have their speed reduced to 0 and fall. Doesn't need to be in foam or net form, but it does need to be a massive-entanglement-object, or MEO for short.
There are small debris clouds, but also large uncontrolled spacecraft, like boosters. De-orbiting those could be a huge help, since a collision with a stray booster would create gobs of debris so those orbits may be completely avoided.
This could work, but would limit effectiveness to the orbits that MUST be very specific to work. For most satellites this doesn't matter. If 500 km is clogged, you design your mission to work at 505 km. I could see something like this working for geostationary orbits and sun-synchronous orbits as they require specific altitudes and inclinations, but not for much else.
Except orbits are neither that precise nor that static, without active control.
Look up the "Gabbard diagram" of any orbital collision. Some of the debris ends up in rather elliptical orbits, with an apogee considerably higher than the orbit of either object that went into the collision. That means it presents a risk to satellites even in higher orbits.
Also, orbits decay. The atmosphere doesn't just stop at a line; there's thinner and thinner wisps of gas out there, ever so slightly dragging on orbiting objects. So higher orbits slowly get lower, and lower orbits rapidly get lower still, until the orbit turns into an entry trajectory.
The properties of the exosphere are fickle and change rapidly, influenced by the solar wind and other forces. So while it's certain that orbiting objects experience drag, it's very uncertain how _much_ drag.
An object in an elliptical orbit spends some of its time with a very low perigee and thus a lot of atmospheric drag and thus its orbit changes rapidly in ways that're hard to predict, even if its apogee is high enough that it also crosses orbits of interesting things that're trying to avoid it. And the less predictable it is, the harder it is to avoid.
An incentive appears to exist to wait for collisions every once in a while so that there's more junk at different levels to clean up, and to prove the need for cleaning up junk.
This is completely off topic but what accent is the narrator speaking?
He pronounces "research" as "resorch"/"resauch", "greater" as "greator" etc. and in other regards it seems to flip between American to slightly British English.
It's an American accent, but with rhotacism, a type of speech impediment. He sounds vaguely British at times because of the tendency for "R" to come out sounding like "W"
It's a speech impediment; he has trouble saying R's (and has improved as he's narrated more and more videos).
Isaac's earlier videos would show Elmer Fudd with the message "Having problems understanding me? Turn on CC." Example: https://youtu.be/gOu3zGfP-TQ?t=40
Source: I've watched lots of his videos and highly recommend them—mind expanding ideas!
Even if someone solves the technical part (cheap recovery), there are multiple practical problems with salvaging.
1. Satellites don't have much to salvage at EoL, they are typically obsolete at this point, at least for their main purpose. Their components degrade as well - space is a fairly aggressive environment and they aren't designed to be reusable.
2. They often contain highly regulated components that have tight export restrictions.
3. They might contain state or trade secrets and recovering by a third party is highly undesirable.
I think the thing you're salvaging is the orbital itself. That has value and the salvager should get a percentage of that. This requires international regulation we don't have though.
Given enough debris at different orbital heights, maybe Woz company can collect it at one location and use it as a launch platform, using the debris as the reaction-mass, then they can use solar power as the energy source to launch to higher orbits, rather than ejecting rocketfuel for thrust. Does this seem feasible? Given certain rocket trajectories, the debris could be made to fall back to earth, solving 2 problems at once - escape velocity energy needs as well as excessive space debris.
*Using space debris as railgun payload, but the railgun (rocket ship) is what you want to accelerate.
Crazy idea: can new satellites be assembled from the parts of old ones: the parts are already in orbit, you can’t reuse chips, but you can reuse solar panels, wires, external walls, etc.
Crazy idea: can new boats be assembled from the wrecks of old boats: the parts are already in the ocean, you can't reuse metal, but you could reuse masts, wood, and hulls, etc.
Even if you assume there are sufficient working parts in orbit to construct working satellites, doing that reconstruction in space would require gathering them together in space either by people (super expensive) or by a sufficiently flexible robot, in which case we're already sending up something, just send up the desired new satellite instead.
Alternatively we could deorbit components without them burning up and assemble new ones down here, but that would also be vastly more expensive than just making new ones down here to begin with.
I've seen this kind of things in many works of science fiction, but it makes a lot of sense when you think about it even for non-space related salvage.
I'm very skeptical of the technical challenges associated with this problem (business model and financing aside). The amount of delta-v required to perform maneuvers to repeatedly "dock" with different pieces of space junk, and then again to de-orbit is very high. You MIGHT be able to de-orbit on the order of magnitude of ~10 pieces of low-earth orbit debris per mission. Maybe. If you're really good. And low-earth orbit junk isn't the major issue since it will de-orbit naturally in a reasonable time-frame. Higher orbit junk is what really matters, and will require much more delta-v to reach, and then again to de-orbit after "docking".
Allow me to blindly speculate here: a space-junk company is going to take one of the two following paths:
1) Perform low-earth orbit missions to de-orbit a few pieces here and then there, use the good PR to drive funding (let's just assume they can make the finances work via getting governments to pay for it or something). It will technically work, but it will only deorbit pieces that would naturally decay anyways at a meaninglessly low-volume. But the PR will be good and regulatory capture will ensure their investors get paid. The real problem will remain.
2) Go after the really big pieces in higher orbits. These pieces tend to be well-tracked and aren't really a large problem, but all the same outcomes in option 1 will occur. Investors will get paid, and of course, the real problem won't be solved.
Maybe I'm being pessimistic, but I see space-junk removal companies largely relying on the general public's lack of knowledge on how orbits work to drive PR. Maybe Kerbal Space Program 2 will go viral enough to fix that problem? We can only hope
The most realistic solution for space junk deorbiting I've seen is the recently tested electromagnetic tether ("Terminator tape"). It is a passive solution that does not require an external spacecraft, and could be activated by a satellite operator when a satellite reaches the end of its lifespan. Perhaps, such system should be made mandatory, maybe even going as far as adding a dead man switch for its automatic activation in case the satellite becomes uncontrollable and stops responding to the commands from the Earth.
But even with this solution removing high orbit debris still remains a hard problem.
This would work great for defunct satellites, but does nothing to solve the bigger space-junk danger: random bits and pieces of things from stage separations and previous collisions that are difficult to track. Definitely a step in the right direction, but it won't solve the largest threat.
There are on the order of... 10s of thousands of intentional satellites.
There are millions of pieces of debris.
It's useful for preventing future debris from dead satellites perhaps, but doesn't address the large number of existing objects which are currently the problem.
My understanding of the issue is that the biggest problems are a few well known defunct satellites in mid altitude orbit. We have no control over them so if two collide we are in big trouble. That almost happened last year. I think someone can make a big difference by targeting those first.
A couple of ideas that come with little knowledge, so take it with a big grain of salt:
1. "Electromagnetic Missile" with trajectory who's apogee is just below the targeted space junk. Turn on the electromagnet when just below the space junk to drag down its trajectory slightly, or even down to a de-orbit trajectory. Obviously, this only works with satellites built with magnetic materials. It may just be my outsider's perspective, but non-orbital missiles seem much easier and cheaper than rockets that go into orbital trajectories. Handling the return of the missile is tricky, perhaps it can also self-detonate fairly high in the atmosphere.
2. Ion engines or space sails driven tugs for use in getting to the space junk. My understanding is ion engines have a really favorable specific impulse. An optional chemical engine could be used to quickly de-orbit the tug upon reaching the satellite. Another idea to speed up de-orbit without requiring the tug the whole way would be a spring that would "push" the junk once it reached it, throwing it into an orbit that would more quickly drop it into the atmosphere. Newton could be used to our advantage to also push the tug into a new orbit to reach the next junk satellite sooner.
Obviously, arm-chair rocket scientist here, so feasibility of the above ideas can probably quickly be dis-proven.
Can you use the junk's energy to power the cleaner? Imagine this: the cleaner has a big spring on the back of it. The spring is slowly compressed using solar power. The orbiter grabs a piece of junk, and then launches it backwards. The cleaner now has gained some of the energy from the junk, and the junk has lost energy.
Going after bigger pieces in higher orbit might not bring much of an immediate benefit, but it can reduce the amount of damage if such an object is hit and shattered into many pieces (Kessler effect comes to mind).
So it might still be very worthwhile in the long term.
Low orbit stuff gets naturally de-orbited after a few years/decades by stray air molecules from the Earth's atmosphere, so there's little point to manually cleaning it. Debris in higher orbits can take centuries or millennia to naturally de-orbit, so manual cleaning there makes more sense.
With my very basic understanding of orbital mechanics, higher orbits require more dV simply because it's further from Earth.
The more interesting bit is that subtle orbital adjustments require much less dV in higher orbits than in lower ones.
I like to think of it like pushing a barrel uphill: it takes more effort if the slope is steep, but then once it's up there, it's a lot easier to get the barrel moving downhill.
Anyways, the "de-orbit" cost follows the same rule of higher being more costly in dV, the big difference with an ascension being that the atmosphere slowing you down is what you want (aerobraking is the word, I think?). So the difference in dV between a high orbit and a low orbit descent isn't proportionate to that of the ascent, if that makes any sense.
Maybe instead of de-orbiting debris they could collect it into a small number of well-known locations. Instead of 10k pieces of space junk to avoid in a particular orbit you could just have one or two. Might have less demanding delta-v requirements that way.
not likely that they will have one craft that is used to deorbit multiple items. more likely there will be one craft with 100 micro/cub satellites in orbit. once junk identified, mother craft ejects micro sat, micro sat performs one single burn to rendevu with junk over a very long period of time. passively connects to it somehow, like magnets or or something, then once connected, then does a single. deorbit burn to change the trajectory of the junk to deorbit significantly faster than normal. sacrifice itself with the deorbit
I remember a idea to use lasers to burn up space debris. Would you be able to just launch somd kind of weapons platform to handle space debris rather than trying to attach and slow them down?
I'm no expert, but is that really a consideration for modern launches? I'm not aware of any space agency that is currently limited in what they can do by orbital debris. Maybe it changes the launch windows, or they adjust an orbit by a few km. But are missions actually being canceled such that they would fund someone to make those missions possible again?
My analysis assumed funding would occur. Pathways 1) and 2) are on the table regardless of the funding. Easy access to funding does not in anyway preclude options 1 and 2
Highly plausible analysis. Hopefully Woz is above the PR stunts and has a real plan for addressing the future problem (it's not really a problem yet, but it will be).
Woz the last 40 years has launched one PR stunt after the other (although, to be fair, I believe he has also done a fair amount of good things quietly in the background in the same time).
"The story of Planetes follows the crew of the DS-12 "Toy Box" of the Space Debris Section, a unit of Technora Corporation. Debris Section's purpose is to prevent the damage or destruction of satellites, space stations and spacecraft from collision with debris (so-called "space debris") in Earth's and the Moon's orbits. They use a number of methods to dispose of the debris (mainly by burning it via atmospheric reentry or through salvage), accomplished through the use of EVA suits."
Once you're assigned an orbit space I would assume it'd be your duty to keep it "clean" and as such owners of orbits would need to either do their own cleanup or contract companies like this.
That being said it feels like a company like this is 50 to 100 years too early, but what do I know.
From a strict physics perspective, I tend to think you are right, but from a messy human perspective I think orbital cleanup companies stand to do a lot of good even if they never retrieve more than a token satellite or two.
Being able to say "You just made a $200M mess," priced on the cost of cleanup, is a lot more powerful than just being able to say "You made a mess." A concrete price tag is a boon for regulation, for liability & enforcement, and even for space startups explaining to their investors why yes, they do have to include fuel budget for the viking funeral, and no, they can't just decide not to, because the alternative is a $200M cleanup fee.
We do regulate orbits. Up until now there have been no cleaner companies so we'll see how that plays in to regulation. "Who will pay for it?" is indeed an interesting question.
It is not too early because the mess produces more mess through collisions, meaning that the sooner you catch it the less expensive it is to fix. Waiting until the problem is directly painful is humanity's normal operating procedure, but it's also like waiting until your cancer is stage 4 before getting it looked at.
First, many satellites share an orbit - for example, the whole GEO is a single orbital path, and it has hundreds, something like 25% of all the world's satellites spread over that path; and any junk that intersects that orbit is a threat to all of them, not any one in particular.
Second, a random piece of space junk is likely to be in a weird orbit where no satellite would want to be, but that potentially crosses/intersects many orbits where we would like to put satellites or have already done so, so again, it threatens many satellites (or "orbital slots"), not any one in particular. An orbit that's "clean" for this rotation might intersect a piece of space junk in the next rotation or a month afterwards; that junk is not "in that orbit" but it's still a threat to that orbit and many others because its path is crossing these orbits.
You could assign responsibility to sources of particular pieces debris; but there simply aren't cleanly separable areas of space for orbits to which you could assign responsibility like we do for radio spectrum.
The big difference from EM is that if you turn of your transmitter the "junk" disappears while space junk can persist for a long time in any orbit that is not extremely close. It is also very unknown how much it will cost to clean up the junk and how spread out it will be (both because space-cleaning is new and that space accidents tend to spread out). It sounds great to have those requirements conceptually but it is also extremely hard to even start to think about what those requirements would be and how to enforce them globally.
Does anyone else see Wozniak as the headliner and shrug? He has no track-record of successful companies since Apple. Why is this news and why did it hit the front page of HN?
2020: Wozniak’s latest venture is called Efforce and aims to use cryptocurrency and blockchain technology to make it cheaper and easier for companies to fund ‘green’ projects.
2017: Steve "Woz" Wozniak, cofounder of Apple Computer and inventor of the Apple II computer, announced on Friday the launch of his latest startup, Woz U.
While I don't claim that Wozniak has any business running a space junk cleanup company - I am confused about your requirement that all founders must be serially successful ones for any of their ventures to matter.
Every "space company" has to have a celebrity name attached to it, right? Even if they're not really a celebrity and no one remembers why they were famous.
I'm cynical about the actual need for the proposed service, but I wouldn't begrudge Woz the opportunity to rent his name out for joy or cash.
I still admire the man for his accomplishments and the role he played in shaping the modern world of computing. But I also recognize that his current role is to provide brand recognition for longshot companies.
I'd be interested in seeing a startup he's intimately involved with as a true cofounder. If he's just on board for name recognition/funding I'm less intrigued.
I do. I respect the guy, but this seems like a "me too" (the traditional meaning, as in someone trying to assert "Hey, I'm a player, too"). It's a worthy cause, but I think his major contribution may be his celebrity cache.
Musk has a name re: Space based on accomplishments, hands down. Branson's move extends the Virgin enterprises, and Bezos has a similar business plan and track record as Branson. But now comes Woz, older and much later to the game, and with no background of experience.
His name, face, and personality will bring in investors, though, I'm sure.
As a note, the manga is a lot less "hard" but no less enjoyable than the anime. For the anime they had a bunch of space folks consult to fix things up so if the space faring details bother you watch that.
Do you have a source for that? The manga I remember being quite accurate (though it's been a decade at least since I last read it). The anime diverges drastically story wise from the manga (the main characters are even different).
I always had this question, though maybe there's a simple answer why nobody is doing this.
Why it's not mandatory to have some smallish engine attached, which at the end of satellite's life would lower the orbit enough until atmosphere picks it up and it will slow down significantly on it's own and burn up?
Is it because most satellites will not fully burn and actually hit the ground, i.e. it's liability?
Is it because of too great of a risk of crossing and colliding with a satellite in another orbit, i.e. liability again?
Is it because "attaching smallish engine" which will fire at satellite's end life is actually really hard thing to do?
The engine is not the problem. It's the fuel. Large orbit changes take a lot. Lowering orbit is not easier than raising orbit, it takes the same delta-v.
IMO what should happen is we should ban putting satellites in high orbits. Satellites in low orbit decay naturally within a few years due to atmospheric drag. Satellites in high orbit will stay there essentially forever. More importantly, any collision in high orbit creates a permanent debris cloud which will spread over time and pollute orbit forever, being essentially impossible to clean up even with sci-fi technology. A collision in low orbit creates a similar debris cloud but it will be naturally cleaned up in a few years or less.
Putting satellites in high orbits made sense back when it was incredibly expensive to launch each satellite, because satellites last longer in high orbit and you don't need as many to cover an area. Also, stationary satellite dishes only work with geostationary satellites, and geostationary orbit is a very high orbit. But today we can use phased arrays to communicate with moving satellites without physically moving a dish, and SpaceX is about to drop launch prices through the floor with Starship, making it feasible to launch enough satellites to cover the Earth even in low orbit and replace them frequently. So to me, the space debris pollution risk of high orbit satellites can no longer be justified.
> Lowering orbit is not easier than raising orbit, it takes the same delta-v.
Why is this? From a layman's perspective it seems like gravity would be a massive form of help here and therefore lowering orbit should require much less fuel.
Well there are other reasons for debris besides just satellites going out of commission. For example in 2007 China deliberately blew up the Fenyun-1C satellite for some kind of research purpose accounting for probably thousands of current pieces of debris up there.
The satellites we put in orbit will naturally have orbits which will decay in a matter of days to hundreds of millions of years. End of life is indeed a consideration for launch approval and many satellites do accelerate their decay with onboard thrust.
Some satellites can’t, would require too much thrust to get back to earth. Some push in to higher orbits to get out of the way for replacement satellites.
Some satellites break in orbit and can’t be controlled.
Yes but the FCC is going the wrong direction with that. Firstly it treats constellations differently than individual satellites which makes no sense from a statistical and mathematical perspective and it would also completely kill off the smallest of satellites that students learn with that are primarily launched by universities.
Readit News
When ships sink, the owner generally still retains ownership of any property. Sometimes the location of the wreck is known. Sometimes it needs to be found. It can cost a lot of money to find a wreck and recover any property.
So salvage rights are a principle of maritime law such that whoever does this is entitled to a reward commensurate with the value of the goods recovered (eg 10%).
I imagine there are orbital slots that are essentially unusable because of space debris (eg Project West Ford [1]). If orbital slots are sufficiently scarce then these could have value. At some point it may become commercial to spend the effort cleaning up an orbit and making it available. Companies could then be compensated for the value they create this way.
I do believe this will still require a dramatic decrease in launch costs, as in orders of magnitude more. But we'll see.
My personal belief (and hope) is that the future of getting into orbit is orbital rings [2]. If so, that completely changes the game because cleaning up an orbit essentially becomes a problem of just holding up a giant "paddle" (for lack of a better word) that is fixed to a point on Earth (essentially) and just letting the debris hit it.
[1]: https://en.wikipedia.org/wiki/Project_West_Ford
[2]: https://www.youtube.com/watch?v=LMbI6sk-62E
https://www.imdb.com/title/tt12838766/
There's also Japanese anime series set in the near-future sci-fi about a small company that cleans up space debris, called "Planet ES"
https://en.wikipedia.org/wiki/Planetes
https://en.wikipedia.org/wiki/Salvage_1
Obviously there's the conservation of momentum to deal with. That fleck of paint has a decent amount of momentum but that's fairly easily absorbed by a couple of tons of material fixed to an otherwise rigid body.
You'd probably attach it via cables and if, somehow, enough momentum was delivered to that "paddle" that it would tear off the cables would just let it go.
If the paddle is fixed to the ring and is let go, it's just going to fall to Earth even with any added momentum, in which case it'll burn up in the atmosphere.
The more dangerous debris is larger stuff. Like there are dead parts of rockets, even smaller stuff like bolts. These pose extra challenges but a lot of the same principles apply.
[1]: https://www.csmonitor.com/Science/2016/0513/Space-debris-dan....
Look up the "Gabbard diagram" of any orbital collision. Some of the debris ends up in rather elliptical orbits, with an apogee considerably higher than the orbit of either object that went into the collision. That means it presents a risk to satellites even in higher orbits.
Also, orbits decay. The atmosphere doesn't just stop at a line; there's thinner and thinner wisps of gas out there, ever so slightly dragging on orbiting objects. So higher orbits slowly get lower, and lower orbits rapidly get lower still, until the orbit turns into an entry trajectory.
The properties of the exosphere are fickle and change rapidly, influenced by the solar wind and other forces. So while it's certain that orbiting objects experience drag, it's very uncertain how _much_ drag.
An object in an elliptical orbit spends some of its time with a very low perigee and thus a lot of atmospheric drag and thus its orbit changes rapidly in ways that're hard to predict, even if its apogee is high enough that it also crosses orbits of interesting things that're trying to avoid it. And the less predictable it is, the harder it is to avoid.
He pronounces "research" as "resorch"/"resauch", "greater" as "greator" etc. and in other regards it seems to flip between American to slightly British English.
Never heard this accent before.
https://en.wikipedia.org/wiki/Isaac_Arthur
Isaac's earlier videos would show Elmer Fudd with the message "Having problems understanding me? Turn on CC." Example: https://youtu.be/gOu3zGfP-TQ?t=40
Source: I've watched lots of his videos and highly recommend them—mind expanding ideas!
1. Satellites don't have much to salvage at EoL, they are typically obsolete at this point, at least for their main purpose. Their components degrade as well - space is a fairly aggressive environment and they aren't designed to be reusable.
2. They often contain highly regulated components that have tight export restrictions.
3. They might contain state or trade secrets and recovering by a third party is highly undesirable.
Deleted Comment
*Using space debris as railgun payload, but the railgun (rocket ship) is what you want to accelerate.
Deleted Comment
Alternatively we could deorbit components without them burning up and assemble new ones down here, but that would also be vastly more expensive than just making new ones down here to begin with.
Allow me to blindly speculate here: a space-junk company is going to take one of the two following paths:
1) Perform low-earth orbit missions to de-orbit a few pieces here and then there, use the good PR to drive funding (let's just assume they can make the finances work via getting governments to pay for it or something). It will technically work, but it will only deorbit pieces that would naturally decay anyways at a meaninglessly low-volume. But the PR will be good and regulatory capture will ensure their investors get paid. The real problem will remain.
2) Go after the really big pieces in higher orbits. These pieces tend to be well-tracked and aren't really a large problem, but all the same outcomes in option 1 will occur. Investors will get paid, and of course, the real problem won't be solved.
Maybe I'm being pessimistic, but I see space-junk removal companies largely relying on the general public's lack of knowledge on how orbits work to drive PR. Maybe Kerbal Space Program 2 will go viral enough to fix that problem? We can only hope
But even with this solution removing high orbit debris still remains a hard problem.
https://www.tethers.com/deorbit-systems/
https://spacenews.com/tethers-unlimited-terminator-tape-smal...
https://www.nasa.gov/offices/oct/early_stage_innovation/niac...
There are millions of pieces of debris.
It's useful for preventing future debris from dead satellites perhaps, but doesn't address the large number of existing objects which are currently the problem.
1. "Electromagnetic Missile" with trajectory who's apogee is just below the targeted space junk. Turn on the electromagnet when just below the space junk to drag down its trajectory slightly, or even down to a de-orbit trajectory. Obviously, this only works with satellites built with magnetic materials. It may just be my outsider's perspective, but non-orbital missiles seem much easier and cheaper than rockets that go into orbital trajectories. Handling the return of the missile is tricky, perhaps it can also self-detonate fairly high in the atmosphere.
2. Ion engines or space sails driven tugs for use in getting to the space junk. My understanding is ion engines have a really favorable specific impulse. An optional chemical engine could be used to quickly de-orbit the tug upon reaching the satellite. Another idea to speed up de-orbit without requiring the tug the whole way would be a spring that would "push" the junk once it reached it, throwing it into an orbit that would more quickly drop it into the atmosphere. Newton could be used to our advantage to also push the tug into a new orbit to reach the next junk satellite sooner.
Obviously, arm-chair rocket scientist here, so feasibility of the above ideas can probably quickly be dis-proven.
Both of those ideas involve getting (and staying) close to them for several seconds.
So it might still be very worthwhile in the long term.
Wait, why? The lower orbit stuff traverses less space so it's easier to make it more dense and hazardous to space travel through that space.
The more interesting bit is that subtle orbital adjustments require much less dV in higher orbits than in lower ones.
I like to think of it like pushing a barrel uphill: it takes more effort if the slope is steep, but then once it's up there, it's a lot easier to get the barrel moving downhill.
Anyways, the "de-orbit" cost follows the same rule of higher being more costly in dV, the big difference with an ascension being that the atmosphere slowing you down is what you want (aerobraking is the word, I think?). So the difference in dV between a high orbit and a low orbit descent isn't proportionate to that of the ascent, if that makes any sense.
"The story of Planetes follows the crew of the DS-12 "Toy Box" of the Space Debris Section, a unit of Technora Corporation. Debris Section's purpose is to prevent the damage or destruction of satellites, space stations and spacecraft from collision with debris (so-called "space debris") in Earth's and the Moon's orbits. They use a number of methods to dispose of the debris (mainly by burning it via atmospheric reentry or through salvage), accomplished through the use of EVA suits."
Basically space garbage men =)
Once you're assigned an orbit space I would assume it'd be your duty to keep it "clean" and as such owners of orbits would need to either do their own cleanup or contract companies like this.
That being said it feels like a company like this is 50 to 100 years too early, but what do I know.
Being able to say "You just made a $200M mess," priced on the cost of cleanup, is a lot more powerful than just being able to say "You made a mess." A concrete price tag is a boon for regulation, for liability & enforcement, and even for space startups explaining to their investors why yes, they do have to include fuel budget for the viking funeral, and no, they can't just decide not to, because the alternative is a $200M cleanup fee.
It is not too early because the mess produces more mess through collisions, meaning that the sooner you catch it the less expensive it is to fix. Waiting until the problem is directly painful is humanity's normal operating procedure, but it's also like waiting until your cancer is stage 4 before getting it looked at.
First, many satellites share an orbit - for example, the whole GEO is a single orbital path, and it has hundreds, something like 25% of all the world's satellites spread over that path; and any junk that intersects that orbit is a threat to all of them, not any one in particular.
Second, a random piece of space junk is likely to be in a weird orbit where no satellite would want to be, but that potentially crosses/intersects many orbits where we would like to put satellites or have already done so, so again, it threatens many satellites (or "orbital slots"), not any one in particular. An orbit that's "clean" for this rotation might intersect a piece of space junk in the next rotation or a month afterwards; that junk is not "in that orbit" but it's still a threat to that orbit and many others because its path is crossing these orbits.
You could assign responsibility to sources of particular pieces debris; but there simply aren't cleanly separable areas of space for orbits to which you could assign responsibility like we do for radio spectrum.
https://www.moneycontrol.com/news/technology/apple-co-founde...
2017: Steve "Woz" Wozniak, cofounder of Apple Computer and inventor of the Apple II computer, announced on Friday the launch of his latest startup, Woz U.
https://www.inc.com/business-insider/steve-woz-wozniak-apple...
I'm cynical about the actual need for the proposed service, but I wouldn't begrudge Woz the opportunity to rent his name out for joy or cash.
Dead Comment
Even naysayers took time to read &/| post.
Musk has a name re: Space based on accomplishments, hands down. Branson's move extends the Virgin enterprises, and Bezos has a similar business plan and track record as Branson. But now comes Woz, older and much later to the game, and with no background of experience.
His name, face, and personality will bring in investors, though, I'm sure.
Dead Comment
Why it's not mandatory to have some smallish engine attached, which at the end of satellite's life would lower the orbit enough until atmosphere picks it up and it will slow down significantly on it's own and burn up?
Is it because most satellites will not fully burn and actually hit the ground, i.e. it's liability?
Is it because of too great of a risk of crossing and colliding with a satellite in another orbit, i.e. liability again?
Is it because "attaching smallish engine" which will fire at satellite's end life is actually really hard thing to do?
Something else?
IMO what should happen is we should ban putting satellites in high orbits. Satellites in low orbit decay naturally within a few years due to atmospheric drag. Satellites in high orbit will stay there essentially forever. More importantly, any collision in high orbit creates a permanent debris cloud which will spread over time and pollute orbit forever, being essentially impossible to clean up even with sci-fi technology. A collision in low orbit creates a similar debris cloud but it will be naturally cleaned up in a few years or less.
Putting satellites in high orbits made sense back when it was incredibly expensive to launch each satellite, because satellites last longer in high orbit and you don't need as many to cover an area. Also, stationary satellite dishes only work with geostationary satellites, and geostationary orbit is a very high orbit. But today we can use phased arrays to communicate with moving satellites without physically moving a dish, and SpaceX is about to drop launch prices through the floor with Starship, making it feasible to launch enough satellites to cover the Earth even in low orbit and replace them frequently. So to me, the space debris pollution risk of high orbit satellites can no longer be justified.
Why is this? From a layman's perspective it seems like gravity would be a massive form of help here and therefore lowering orbit should require much less fuel.
The satellites we put in orbit will naturally have orbits which will decay in a matter of days to hundreds of millions of years. End of life is indeed a consideration for launch approval and many satellites do accelerate their decay with onboard thrust.
Some satellites can’t, would require too much thrust to get back to earth. Some push in to higher orbits to get out of the way for replacement satellites.
Some satellites break in orbit and can’t be controlled.
https://en.m.wikipedia.org/wiki/Graveyard_orbit