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Recycling Orbital Debris


shynung

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You have just described the concept much better than I did.

Though, for some reason, the first thing people think about doing on space junk (even here) is to deorbit them and be done with it. I wonder, why?:rolleyes:

Probably because launching a mobile reprocessing lab (which doesn't exist) is more expensive and less reliable than launching a pile of new spacecraft.

Even if the long term costs of recycling were lower, no agency can get the money to create something to harvest materials for unplanned and unfunded missions.

Harvesting materials in space will not be useful or economical until lots of people are actually living in space.

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True, there isn't much of humanity in space anyway; we haven't really reached the proper 'space age'.

Even if projects in space are proven in profitability, there just aren't many customers around. ISS or the upcoming Russian station at least, various orbital telescopes and labs at most (and there aren't many of them).

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It would take a huge amount of dV to bring all those bits of debris to a common orbit for recycling and reuse.

The energy balance between moving and recycling debris and launching new hardware is largely in favor of the latter and will remain so for a long time.

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The energy balance between moving and recycling debris and launching new hardware is largely in favor of the latter and will remain so for a long time.

I just *DEMONSTRATED* that's not true to you with a working, economical Scrapper Ship system I have been using *FOR THE PAST 6 MONTHS*, and yet still you insist on that assertion. Are you mad, man? Insanity and faith/religion are the only possible explanations I can think of for denying a fact when it's starting you right in the face...

Regards,

Northstar

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What you demonstrated add the ability to rendesvuz with debris. That's the easy part, could you please explain the process of recycling said debris including the energies required?

The energies required to perform the actual recycling/disassembly (in real life) hardly matter first of all- solar panels provide a virtually unlimited supply of power (at a slow rate), assuming your disassembly plant is mostly or all robotic, and doesn't need to waste most of its energy on energy-hungry life support systems for a large crew...

Also, once a solar panel is launched and deployed on a space station, it's a more or less one-time cost (except for small costs in maintenance and a tiny % increase in station-keeping costs: the latter of which are less significant in higher orbits), so it doesn't add much to the fuel costs of a long-term high-capacity scrapping operation like I demonstrated here.

Admittedly, there are no energy costs to recycle the rocket debris in my system, aside from the solar panels necessary to run the Scrapper Ship itself. But, that's because the mods are abstracted and built for simplicity/fun...

Sure, they *COULD* require me to launch a heavy and electricity-hungry robotic-disassembly/recycling plant to orbit that would carry out the actual recycling of hauled/towed debris- but it wouldn't actually change the economics at all, aside from requiring a one-time heavy launch cost to launch the recycling plant in the first place... It would only make my scrapping operations more boring, less fun, and a bit slower to pay for themselves- but no less profitable in the long run.

Regards,

Northstar

P.S. If what you meant is that all you saw is my flying at the debris at slow speeds, that's because that's virtually all there is to see in that album. In a few of my other albums, I show the RocketParts inventory of the Scrapper Ship before and after recycling a ship. But there's not much to see in terms of the actual recycling- it's not animated or anything. You simply fly at the debris, and it disappears- with an equivalent mass of "RocketParts" being deposited in your ship's RocketParts storage modules after a few seconds...

Once again, they could have required a slower and more energy-hungry recycling process, and a heavy disassembly/recycling module to perform it- but all that means is that I would have had to use an Advanced Grabbing Unit (which didn't exist back when the mods this relies on were introduced) to grab the debris, and tug it back to a space station- where it wouldn't matter how slow, heavy, or power-hungry the actual disassembly/recycling plant was... That would have cost exactly the same fuel/Delta-V, and just been a lot more annoying.

Edited by Northstar1989
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So you "demonstrated" real life capability of such a thing by using it "for 6 months" (I doubt you let KSP run for 6 months at 1x acceleration, so stop using those ridiculous bold-texts-in-stars) in a game, while using a mod that simplifies that a _lot_¿ You really think this is sufficent¿

I also do not see how you ship gets powered. Getting such amount of fuel up to reach different orbits is probably worse than just sending up new satellites/ships.

Also, energy for the recycling is a problem. You will need to smelt down metals, do some chemistry, and such things. Some of those will need temperatures to be well above 1000K on some larger object inside a rather relevantly sized station (not just some meters, but probably hundreds of them). Not impossible, but really expensive and complicated. If you can send up that amount of stuff (we are talking of more than a thousend ISS's I think), recycling satellites is probably not worth it.

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I just *DEMONSTRATED* that's not true to you with a working, economical Scrapper Ship system I have been using *FOR THE PAST 6 MONTHS*, and yet still you insist on that assertion. Are you mad, man? Insanity and faith/religion are the only possible explanations I can think of for denying a fact when it's starting you right in the face...

Regards,

Northstar

In KSP? How could you make it economical when there is no economical aspect to the game? Let me guess: all your debris is on an equatorial orbit at pretty much the same altitude, right?

Unlike KSP, in real life, stuff is launched into all sorts of different inclinations and altitudes. To rendez-vous with each tiny piece of debris, an "orbital scrapper" would have to perform dozens of extremely costly manoeuvers. That's a hell of a lot of energy (and therefore heavy propellant) for a few tons of scrap metal, composite fairings, screws, covers, paint flakes...

And once you have all that crap, what do you do with it? An orbital smeltering furnace or garbage recycling facility is not going to be cheap.

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And once you have all that crap, what do you do with it? An orbital smeltering furnace or garbage recycling facility is not going to be cheap.

Sorting it would be an unbelievable nightmare too. What the hell do you do with composite materials? Pretty much everything used in a spacecraft is a composite or an alloy, breaking these things down to their constituent raw materials and reworking them into a form where you could even feed them into a manufacturing process is often uneconomical down here on Earth. Doing it in orbit is just a little bit crazy. We are such a long way from being able to carry out manufacturing processes in orbit, let alone doing it to aerospace standards. What the OP is proposing is such far-future tech that's it's difficult to say anything coherent about it.

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In KSP? How could you make it economical when there is no economical aspect to the game?

By a rather simple measure- how many rocket launches I have to make to maintain my operations in space.

It would have taken me a LOT more launches to get as much mass to orbit as it did to simply recycle what was already there. It took a lot FEWER launches to get the fuel up- and like I said, you can actually produce fuel on the Mun using ISRU- in which case, fuel consumption doesn't matter.

Let me guess: all your debris is on an equatorial orbit at pretty much the same altitude, right?

No. In fact, I salvaged debris from all kinds of orbits- inclined, elliptical, low, high, even in orbit around the Mun. The debris was scattered all over the place. I would appreciate if you would stop acting like a cynical and hostile %#$% though. This is supposed to be a *friendly* gaming community.

Unlike KSP, in real life, stuff is launched into all sorts of different inclinations and altitudes. To rendez-vous with each tiny piece of debris, an "orbital scrapper" would have to perform dozens of extremely costly manoeuvers. That's a hell of a lot of energy (and therefore heavy propellant) for a few tons of scrap metal, composite fairings, screws, covers, paint flakes...

It's more than a "few tons" of material. Most of what I was recycling was spent upper stages used to carry payloads to orbit, or drop tanks from interplanetary transfers (which meant it was in a *HIGHLY* elliptical orbit). The fuel consumption wasn't pretty, which is why I said the margins were "a bit low", but it was worth it for what literally added up to HUNDREDS of tons of recycled material (in fact, over a thousands tons in total- I have a very active space program).

And once you have all that crap, what do you do with it? An orbital smeltering furnace or garbage recycling facility is not going to be cheap.

In-game, I can immediately re-use it. I build a new rocket, or space station, or satellite with the RocketParts I get from salvaging- simple as that.

In real life, you're making the *HIGHLY INACCURATE* assumption that you have to make use of a recycling pattern known as "downcycling"- where you degrade something to be recycled into its base components before making something new from scratch. I don't entirely blame you for making that assumption- most people are only familiar with recycling through the common processes of recycling things like paper, cardboard, metal, glass, etc.

That is NOT the type of recycling that would be useful in space, however. Think of something more similar to how we recycle computers or cell phones in real life- we either clean and fix up reusable components, sometimes re-using an entire part or product (as with cell phones), or we only salvage the highly valuable metals and minerals that can be easily accessed- such as gold and other rare metals from some computers, and throw out the rest...

In such a case, you don't need *nearly* as much energy, and you don't need to smelt large amounts of things in orbit. You end up tearing apart some things to get at valuable components (and throwing the rest away), whereas with others you simply reuse it whole: as with a drop tank, which you should simply be able to re-attach to another rocket (in fact, although it is a bit more complex, if I wanted I could actually do this by only attaching my drop tanks with radially-placed docking ports instead of decouplers...)

What I'm talking about is more comparable to a junkyard tearing still-serviceable parts out of used/wrecked cars, than a metal recycling plant melting everything down and starting again from scratch (on Earth, we downcycle because the financial costs of doing so are less than junkyard-type recycling, as labor is more expensive than heavy infrastructure, and the atmosphere convects away hear. In space, the opposite applies for nearly every factor when using a robotic disassembly strategy- so a junkyard strategy is superior.)

You wouldn't need a giant station to run an orbital junkyard. In real life you might have a station half or a third the size of the ISS easily performing all the necessary functions. Not cheap to build, to be sure, but if you're producing fuel on the Mun/Luna you have an essentially unlimited supply of free fuel available for your scrapper ships (establishing 100% reusable supply lines from the Munar/Lunar surface to anywhere in the Kerbin/Earth system is comparatively trivial), whereas every single ton of Dry Mass you ship to orbit is going to cost you dearly. The same principle applies in real life.

Regards,

Northstar

Edited by Northstar1989
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So you "demonstrated" real life capability of such a thing by using it "for 6 months" (I doubt you let KSP run for 6 months at 1x acceleration, so stop using those ridiculous bold-texts-in-stars) in a game, while using a mod that simplifies that a _lot_¿ You really think this is sufficent¿

I ran dozens of missions during that time, and even more scrapping operations. I suggest you actually take a look at the links I posted to my thread before you start talking out of ignorance of what I actually did...

I also do not see how you ship gets powered. Getting such amount of fuel up to reach different orbits is probably worse than just sending up new satellites/ships.

Actually, you can see where the scrapper ship is getting its fuel in several of the screenshots. Not only does it obtain leftover fuel from some of the debris itself (sometimes it's the best strategy to drop a stage before it's 100% empty), but it also obtains a large amount of fuel from the orbital station you see it returning to in several of the screenshots.

That station is at a convenient 350 km equatorial orbit, and is where I drop off all the debris I salvage, as well as pick up more fuel for the scrapper ship. Most of the station's fuel came from several very-heavy tanker launches shortly after it was established (before the scrapping operations ever got underway), but once that starts to run low, I will be establishing ISRU fuel-production on the Mun and Minmus (electrolyzing available water-ice).

If the water-ice wasn't available, or I had some reason to roleplay save the water-ice for other purposes (such as life-support for an eventual Munar colony), though in KSP-Interstellar the amount of water ice is assumed to be so large as to be effectively unlimited for a player's purposes (however in real life, though evidence indicates Luna has some rather considerable ice deposits in some of its northern craters in, the deposits are probably by no means vast or unlimited...), then I would just run all my operations off Aluminum-Oxygen hybrid rockets: which obtain all their fuel from electrolyzing aluminum-rich regolith (which *IS* available in effectively unlimited quantities in real life).

Also, energy for the recycling is a problem. You will need to smelt down metals, do some chemistry, and such things. Some of those will need temperatures to be well above 1000K on some larger object inside a rather relevantly sized station (not just some meters, but probably hundreds of them). Not impossible, but really expensive and complicated. If you can send up that amount of stuff (we are talking of more than a thousend ISS's I think), recycling satellites is probably not worth it.

You're talking about "downcycling" again, probably inspired by how we recycle paper or plastic...

See my other post- this isn't the way you would run a salvage operation in space (at least not until you had a VERY significant presence there, centuries ahead of where we are now). Instead, you would run recycling operations in a manner more similar to how we recycle used cars, cellphones, or computers- where the individual components are valuable, and can often be re-used without doing anything to them other than detaching them from the rest of the vehicle/device.

Regards,

Northstar

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Northstar, I think you're getting a little overheated. :P

I agree with what Nibb and Seret has put forward. Trying to recycle space junk by refining them into their constituent elements probably need literally tons of complicated machinery, with considerable power requirements, along with high durability and reliability standards to boot. It's not going to be cheap.

Even if it's ever profitable, it is probably in the same realm as asteroid mining or moon mining, just with different material sources and industrial processes involved. Having any of these sorts of businesses would be moot if there are nobody to buy the products, namely orbital industries, of which none are currently operating.

Also, even if one were to plan to recycle the space junks as it is, there are plenty of complications to overcome. Old bolts, nuts, and screws may look reusable, but some would probably have worn threads. Whole upper stages recovered intact may be reusable, but there may be cracks, dents, or otherwise imperfections that need to be repaired before use. Old solar panels may have dead PV cells that need replacements, circuitry boards may have blown some components, and the list goes on. Building something able to separate these from less-valuable space junk (paint flakes, insulation pieces, ballast weights), inspect them for damages, repair or otherwise process them into usable products, all while being efficient, reliable, durable, and needing very little human intervention would be a serious engineering challenge.

Despite all the points I have put forth, I deeply respect your trials and experiments regarding this concept. Thank you very much.:)

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As I said. What is the process for recycling? How do you dismantle the debris? What do you do with the products? How big is it? How quickly does it operate?

How do you dismantle a used car in a junkyard? You look at the vehicle, and you decide based on its form and structure what the best way is to get at the components you really want- doing as little damage as possible to less valuable but still useful components in the process. Any such station would be equipped with a variety of robotic arms, grippers, and cutting tools- and probably several independently-mobile robots powered by umbilical cords as well...

You would be aiming to cut things like batteries, engine components, and working electronics out of debris most of the time- doing as little damage to the rest of the structure as possible, so you could re-use some of the undamaged fuel tanks or use some of the structural components (metal sheeting, girders, nuts/bolts/screws, etc.) to build new rockets, stations, satellites, etc...

You would NOT equip such a station with any equipment for melting down large amounts of metals, etc.- though you might have a couple *very small* such (electrically-powered) devices for melting some of the softer, rarer, and more valuable metals with lower melting-points (such as gold, silver, and platinum) out of non-reusable (damaged) circuit boards and other electronic devices on a small scale...

Regards,

Northstar

Edited by Northstar1989
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Northstar, I think you're getting a little overheated. :P

I'm not the one verging on turning some of this into a personal attack. You might want to tell that to some of the other guys- who criticized me, for instance, for saying "6 months" without even bothering to read any of my thread to see that I was indeed doing a lot of stuff over those 6 months (and I didn't always even post every time I carried out a scrapping operation- so even more such operations ran in the background than were posted on my thread).

I agree with what Nibb and Seret has put forward. Trying to recycle space junk by refining them into their constituent elements probably need literally tons of complicated machinery, with considerable power requirements, along with high durability and reliability standards to boot. It's not going to be cheap.

I never suggested downcycling things back into their constituent elements. That wouldn't be cost-effective, and will probably never happen.

Even if it's ever profitable, it is probably in the same realm as asteroid mining or moon mining, just with different material sources and industrial processes involved. Having any of these sorts of businesses would be moot if there are nobody to buy the products, namely orbital industries, of which none are currently operating.[/quote[

Asteroids and moon-mining are going to occur some day, sooner than you think. The first and most obvious/important use for these operations isn't actually mining for metals or raw materials- it's mining for propellant to fuel other space operations- so that you don't have to launch nearly as large rockets from Earth, or can launch much larger vessels, and then refuel them in-orbit.

(Don't forget that, for all its common use by KSP players, orbital refueling still isn't really a thing in the real world. The main reason for this is because the economics for it just don't make sense when you have to ship all your fuel up from the ground- launching a separate fuel tanker or refueling station actually increases the total mass you have to launch to orbit by quite a bit. Not so if you are leveraging your mass, by instead launching the equipment for In-Situ Resource Utilization for off-planet fuel production from the moon or Near-Earth asteroids...)

Also, even if one were to plan to recycle the space junks as it is, there are plenty of complications to overcome. Old bolts, nuts, and screws may look reusable, but some would probably have worn threads. Whole upper stages recovered intact may be reusable, but there may be cracks, dents, or otherwise imperfections that need to be repaired before use. Old solar panels may have dead PV cells that need replacements, circuitry boards may have blown some components, and the list goes on. Building something able to separate these from less-valuable space junk (paint flakes, insulation pieces, ballast weights), inspect them for damages, repair or otherwise process them into usable products, all while being efficient, reliable, durable, and needing very little human intervention would be a serious engineering challenge.[/quoteS]

The difficulties of reusing old and potentially damaged parts and components are overcome everyday by junkyards here on Earth. It's not as if we don't know how to remove parts that look undamaged, and test their function with various devices... In orbit, there are additional engineering challenges to overcome due to working in zero-G, but they're nothing we can't figure out how to handle...

These recycling/scrapping operations wouldn't be carried out by programming- they'd mostly be carried out by remote-control from Earth. The biggest challenge would probably actually be in finding the workforce to control such a station here on the ground. But, it would provide jobs here on Earth, and be worth the saved launches- and you know politicians always love saving money and creating jobs...

Despite all the points I have put forth, I deeply respect your trials and experiments regarding this concept. Thank you very much.:)

Why don't you give it a try yourself? It's challenging, and requires a considerable amount of infrastructure to do it properly (an orbital station to collect the recycled materials, and orbital construction equipment to re-use them at a minimum, but preferably also ISRU fuel production on the Mun or Minmus...), but then you can say you've given it a chance yourself rather than just talking about it. And if you think the current mods that allow this are too oversimplified or easy- then why don't you work on a mod for it of your own (if you have the programming expertise), or give feedback to the authors of existing mods?

Personally, for instance, I think one good way to increase the realism/difficulty factor would be to make the Recyclnig Bin produce a "salvaged parts" resource, that then had to be processed into RocketParts at a specialize facility in order to use them.

And I also think the current Orbital Construction/ Extraplanetary Launchpads system for orbital construction is a bit too easy- there used to be an inefficiency factor in building new vessels this way (you needed something like an extra 20% of the mass of the new vessel in RocketParts to build it), and I think this factor should be re-introduced (it is no longer present in the newest versions- construction is 100% efficient).

All this is the furthest level of difficulty that I, or most other players, would be willing to put up with though. As I said, the margins are already pretty low if you're shipping up the fuel to run your salvaging operations from Kerbin, and even though it's a *LOT* more profitable with ISRU fuel-production, it still already requires a large investment of player time, design, and effort to carry out salvaging operations properly: which is why I am (AFAIK) the first, and still the *only* player to have so far ever successfully established a significant orbital scrapping operation in Kerbal Space Program... (at least, the only one to have ever posted about having done so on the forums)

Regards,

Northstar

Edited by Northstar1989
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You are talking about a game that is a huge simplification of reality. We are talking about complex real-life industrialisation. There are multiple problems with your idea:

- Most rocket stages are not refuelable, restartable or recoverable. They are designed to be disposable. They are not rated to survive more than a few minutes or hours in space. The paint tarnishes and peels off. Insulation materials flake off. Toxic residuals aggregate around the debris. One-go valves are gone. Pyros and ullage motors are spent. Any rubber or soft material will outgas and go brittle. Tanks deform when they lose pressure. Ablative material is destroyed. You would basically have to either redesign all your hardware to be reusable (with a large cost, complexity, and weight penalty) or plan for a total teardown-rebuild on orbit.

This is the main reason why Space Shuttle ETs were never put to use. There were proposals to collect them on orbit and to build huge wet-tank space stations out of them. However, when you look closer at the idea, it's an inherantly bad idea. The insulation material was not space-rated and would have formed a cloud of flaking orange foam debris all around the tank, making the approach and docking hazardous. The modifications needed to stabilize and reuse the tanks would have used too much weight and reduced the payload fraction (docking rings, airlocks, internal fixtures, avionics, RCS...) and the orbital refurbishment work would have been too complicated. It was cheaper to build and launch dedicated space station modules.

- The inspection and refurbishment work on individual components would be tremendous. Manned EVAs are long, dangerous, and require planning and training. You would need facilities for storage, repair, crew support. Look at the VAB or the SpaceX HIF at KSC. That's the sort of facility that is required to assemble and integrate a spacecraft with brand new components on the ground. Now imagine the complexity of constructing such a building on orbit, with support for the dozens of workers that are needed. Imagine the number of SLS flights such a building would need.

- The sheer effort of getting to the debris, catching it, then taking it back to your orbital facility is going to use propellant. That propellant will need to be sent up. You will also need to send up spare parts, seals, paint, pyros, insulation... Everything that can't be recovered from a spent stage, including some large parts like engine nozzles. You will also need to send up the propellant needed to refuel that stage. That's 90% of the weight of a rocket stage. To do that, you'll need a tanker spacecraft, which is basically a rocket stage with it's own power, tug avionics, manoeuvering system, docking, and refueling capability. A tanker spacecraft is therefore going to be heavier than an actual equivalent rocket stage. So you refill your refurbished rocket stage and you are left with a spent tanker. Therefore, you might as well have sent up a brand new rocket stage and saved yourself the expense of refurbishing the old one and now refurbishing the tanker stage.

Hardware is cheap. People are expensive. A worker on the ground costs thousands of times less than a worker in space. That's why we build stuff on the ground and launch it to space. The whole effort of paying billions to put people in space to refurbish hardware that costs a few millions is simply not worth it.

Edited by Nibb31
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Oi vey. The sheer amount of water and detergents required for recycling precludes the use of that junk up there in-situ. It would have to be deorbited to be of any use. We just don't have any way of moving that much mass into orbit.

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- Most rocket stages are not refuelable, restartable or recoverable. They are designed to be disposable. They are not rated to survive more than a few minutes or hours in space. The paint tarnishes and peels off. Insulation materials flake off. Toxic residuals aggregate around the debris. One-go valves are gone. Pyros and ullage motors are spent. Any rubber or soft material will outgas and go brittle. Tanks deform when they lose pressure. Ablative material is destroyed. You would basically have to either redesign all your hardware to be reusable (with a large cost, complexity, and weight penalty) or plan for a total teardown-rebuild on orbit.

A total teardown-rebuild is precisely what I've described, several times now. And performed by robots, not humans- so the time it takes is a lot less of a factor. Are you actually reading my posts?

This is the main reason why Space Shuttle ETs were never put to use. There were proposals to collect them on orbit and to build huge wet-tank space stations out of them. However, when you look closer at the idea, it's an inherantly bad idea. The insulation material was not space-rated and would have formed a cloud of flaking orange foam debris all around the tank, making the approach and docking hazardous. The modifications needed to stabilize and reuse the tanks would have used too much weight and reduced the payload fraction (docking rings, airlocks, internal fixtures, avionics, RCS...) and the orbital refurbishment work would have been too complicated. It was cheaper to build and launch dedicated space station modules.

I'm not proposing something like a wet-lab (that's what those proposals were called "Wet Lab" proposals), and I never made use of it myself. What I'm proposing is ripping out and re-using individual sub-components.

- The inspection and refurbishment work on individual components would be tremendous. Manned EVAs are long, dangerous, and require planning and training. You would need facilities for storage, repair, crew support. Look at the VAB or the SpaceX HIF at KSC. That's the sort of facility that is required to assemble and integrate a spacecraft with brand new components on the ground. Now imagine the complexity of constructing such a building on orbit, with support for the dozens of workers that are needed. Imagine the number of SLS flights such a building would need.

You clearly didn't read my posts at all. The inspection and refurbishment work would need to be performed entirely by robots. Designing and building those robots on the ground here on Earth would be the biggest challenge associated with such a project. And you DO NOT need something the size of the VAB to build a rocket it space.

First of all, the vast majority of the structure is concerned with simply sheltering the rocket from the elements (hence the large hanger). You wouldn't build new rockets/stations/satellites etc. in an enclosed environment in space. In a worst-case scenario, you'd deploy a debris-shield retrograde of the vessels under-construction.

Second, much of the rest of a VAB structure would be filled with things like offices (unnecessary in a robotic facility) and labs to test new components (any component already in space would have been previously tested on the ground- and once again, there's no need for testing for damage to be performed in an enclosed space. You don't need an enclosed room, or floors for humans to walk around, in a robotic zero-G facility.

Third, as I've stated multiple times, SUCH A FACILITY WOULD BE UNMANNED, and entirely run by robots (perhaps with occasional visits from maintenance crews on the ground or at nearby manned stations- though the station would have a large degree of self-repair capacity, as the very tools used to disassemble/salvage a rocket could be used to repair damaged systems on the salvaging station by remote-control...

- The sheer effort of getting to the debris, catching it, then taking it back to your orbital facility is going to use propellant. That propellant will need to be sent up.

I already addressed that issue. Read my bloody posts! That's the main, in fact only, cost associated with such a salvaging station, once you get it all in orbit and assembled, aside from occasional repair visits (if the need for these was frequent enough, you might have a one or two-man repair crew on-board a manned section of the station, which might double at filling many of the research roles of a station such as the ISS when the crew was not busy making repairs...), and the cost of launching the fuel to orbit is a lot less than the cost of all the mass and expensive equipment you save having to launch to orbit this way... In the words of an earlier poster, even a single nut/bolt might be worth hundreds of dollars (though that's a bit of an exaggeration, it DOES cost over a hundred dollars to get a single kg to orbit...) And, you can reduce this cost to ZERO by obtaining all your propellent through ISRU on the moon and near-Earth asteroids...

You will also need to send up spare parts, seals, paint, pyros, insulation... Everything that can't be recovered from a spent stage, including some large parts like engine nozzles. You will also need to send up the propellant needed to refuel that stage. That's 90% of the weight of a rocket stage. To do that, you'll need a tanker spacecraft, which is basically a rocket stage with it's own power, tug avionics, manoeuvering system, docking, and refueling capability. A tanker spacecraft is therefore going to be heavier than an actual equivalent rocket stage. So you refill your refurbished rocket stage and you are left with a spent tanker. Therefore, you might as well have sent up a brand new rocket stage and saved yourself the expense of refurbishing the old one and now refurbishing the tanker stage.

The tanker spacecraft, first of all, could be made 100% reusable to avoid that problem. Space-X style launches will probably be the main enabling factor that makes orbital recycling worthwhile. In KSP, on the other hand, there's no need to wait for Space-X: I already have made several such launches myself, and will probably be making a LOT more of them once budgets are implemented and I have sufficiently advanced through the tech tree again (I plan on starting a new Career game with 0.24, as I suspect many players do...)

You're also making assumptions again- you're assuming that the tankers wouldn't be significantly larger than the rockets being refueled (the larger a fuel tank, the relatively less mass it needs to have compared to its volume, so you save mass if you use on large tanker to refuel several smaller rockets- this is simple geometry), that the only vessels being built would be interplanetary rockets (a large number, in fact the majority, of salvaged parts would probably best be used to construct new space stations and satellites. That way, if something goes wrong with a re-used part, it's a lot easier to access and fix it than if that part is on an interplanetary vessel- and large numbers of structural panels built out of the material of salvaged rockets would make for useful supplementary/extra shielding against micrometeorites and radiation on the crew compartments manned stations, after the chipping paint were removed...), and that the total mass of debris salvaged wouldn't add up to anything significant- despite debris being 10% of each spent rocket's original mass... (looked at objectively, that's actually a rather significant mass to salvage)

Hardware is cheap. People are expensive. A worker on the ground costs thousands of times less than a worker in space. That's why we build stuff on the ground and launch it to space. The whole effort of paying billions to put people in space to refurbish hardware that costs a few millions is simply not worth it.

How many times do I have to say that the salvaging station would need to be UNMANNED, run by robots? You wouldn't be sending up people (except repair crews), only hardware.

Regards,

Northstar

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Oi vey. The sheer amount of water and detergents required for recycling precludes the use of that junk up there in-situ. It would have to be deorbited to be of any use. We just don't have any way of moving that much mass into orbit.

It's ironic that you call yourself "Phoenix" on the forums, yet call an orbital recycling program impossible. Because your username is precisely the name of the real-life "Phoenix Program" that is going to be the first to demonstrate the effectiveness of orbital recycling of satellites:

http://www.space.com/25628-darpa-phoenix-satellite-recycling-project.html

Enjoy the read (and video). I know it's a far cry from the kind of full-scale junkyard-recycling I'm talking about, but the robotic systems needed for it are precisely the ones that would begin to enable an unmanned salvaging plant like I'm talking about. Try actually digesting it, instead of just ignoring what I have to say, forcing me to repeat myself over and over, like these other guys

Regards,

Northstar

Edited by Northstar1989
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That is NOT the type of recycling that would be useful in space, however. Think of something more similar to how we recycle computers or cell phones in real life- we either clean and fix up reusable components, sometimes re-using an entire part or product (as with cell phones), or we only salvage the highly valuable metals and minerals that can be easily accessed- such as gold and other rare metals from some computers, and throw out the rest...

To be practical the original spacecraft would have had to be designed with this in mind originally. In reality things like discarded stages are really only designed to operate for their expected useful life (which is very short). Re-use once in orbit would have to be designed in, the same way that ground maintenance activities like replenishment and inspection need to be designed in.

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You're talking about "downcycling" again, probably inspired by how we recycle paper or plastic...

No I am not, I explicitely mentioned metals, which at the very least need smelting. If you are as picky as you say (only use the most valuable parts), then you might only salvage 1% or less as e.g. the hull will be close to useless in most cases.

Your other objections were already answered by others I think.

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I'm not the one verging on turning some of this into a personal attack. You might want to tell that to some of the other guys- who criticized me, for instance, for saying "6 months" without even bothering to read any of my thread to see that I was indeed doing a lot of stuff over those 6 months (and I didn't always even post every time I carried out a scrapping operation- so even more such operations ran in the background than were posted on my thread).

Ummm.... Okay. Whatever you say.:rolleyes:

I never suggested downcycling things back into their constituent elements. That wouldn't be cost-effective, and will probably never happen.

Agreed.

Asteroids and moon-mining are going to occur some day, sooner than you think. The first and most obvious/important use for these operations isn't actually mining for metals or raw materials- it's mining for propellant to fuel other space operations- so that you don't have to launch nearly as large rockets from Earth, or can launch much larger vessels, and then refuel them in-orbit.

In that case, shouldn't we be mining comets rather than space junk? They are big boulders of water-ice hurling around in space, anyway.

We have to get past the 'hurling around in space' problem first, but I don't think it is too hard to attempt.

(Don't forget that, for all its common use by KSP players, orbital refueling still isn't really a thing in the real world. The main reason for this is because the economics for it just don't make sense when you have to ship all your fuel up from the ground- launching a separate fuel tanker or refueling station actually increases the total mass you have to launch to orbit by quite a bit. Not so if you are leveraging your mass, by instead launching the equipment for In-Situ Resource Utilization for off-planet fuel production from the moon or Near-Earth asteroids...)

Our current ISRU tech is pretty basic, as far as I know. We know what it is supposed to do and how, but I do not know of any space-worthy working examples.

The difficulties of reusing old and potentially damaged parts and components are overcome everyday by junkyards here on Earth. It's not as if we don't know how to remove parts that look undamaged, and test their function with various devices... In orbit, there are additional engineering challenges to overcome due to working in zero-G, but they're nothing we can't figure out how to handle...

These recycling/scrapping operations wouldn't be carried out by programming- they'd mostly be carried out by remote-control from Earth. The biggest challenge would probably actually be in finding the workforce to control such a station here on the ground. But, it would provide jobs here on Earth, and be worth the saved launches- and you know politicians always love saving money and creating jobs...

I agree that the process itself would be carried out by various robots, sensors, and automated machineries. It's the cost of these stuff that is being the problem. Also, if these sorting jobs is ultimately repetitive and predictable, even ground control stations wouldn't even be needed.

Why don't you give it a try yourself? It's challenging, and requires a considerable amount of infrastructure to do it properly (an orbital station to collect the recycled materials, and orbital construction equipment to re-use them at a minimum, but preferably also ISRU fuel production on the Mun or Minmus...), but then you can say you've given it a chance yourself rather than just talking about it. And if you think the current mods that allow this are too oversimplified or easy- then why don't you work on a mod for it of your own (if you have the programming expertise), or give feedback to the authors of existing mods?

I'd try it myself, if my aging computer system would have allowed it.

Also, I have little actual space junk in my saves; all of my upper stages have probe cores on them, so I could crash it somewhere after the job is done.

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No I am not, I explicitely mentioned metals, which at the very least need smelting. If you are as picky as you say (only use the most valuable parts), then you might only salvage 1% or less as e.g. the hull will be close to useless in most cases.

Your other objections were already answered by others I think.

Metals don't necessarily need smelting. Not if the form they come in is already re-usable, anyways...

For instance, there's no reason you can't tear apart a metal hull, and re-use the sheet metal as micrometeorite shielding on a space station. Or metal engine components as spare parts for an interplanetary mission (someday). Or even re-use half an empty fuel tank as a bin to hold some of the junk you've just salvaged...

And, when it comes right down to it, small-scale smelters aren't necessarily impossible in space either. Difficult to engineer, yes, but not impossible.

Regards,

Northstar

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In that case, shouldn't we be mining comets rather than space junk? They are big boulders of water-ice hurling around in space, anyway.

We have to get past the 'hurling around in space' problem first, but I don't think it is too hard to attempt.

There's kind of that whole "hurtling around in space" part to deal with. Comets, unlike some asteroids, tend to be on highly elliptical orbits- and thus actually would cost a LOT of Delta-V to get to or capture in Earth orbit...

Our current ISRU tech is pretty basic, as far as I know. We know what it is supposed to do and how, but I do not know of any space-worthy working examples.

I was pointing out that In-Situ Resource Utilization (which isn't a thing for many KSP players) is actually likely to become a thing sooner than fuel tankers launched from Earth (which *is* a thing for many KSC players).

And actually, there is already a working Sabatier Reactor on the International Space Station, being used for life-support. It's not much of a stretch to use the same reactor on Mars to make methane for an interplanetary mission's return-trip to Earth... (you send the reactor ahead of the mission, and make the return fuel before the astronauts ever leave Earth...)

http://www.nasa.gov/mission_pages/station/research/news/sabatier.html

I'd try it myself, if my aging computer system would have allowed it.

Also, I have little actual space junk in my saves; all of my upper stages have probe cores on them, so I could crash it somewhere after the job is done.

My computer's older than most out there, and it somehow manages to handle it (admittedly, my game *is* a little laggy). Don't be so sure yours couldn't before giving it a try...

Regards,

Northstar

Edited by Northstar1989
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There's kind of that whole "hurtling around in space" part to deal with. Comets, unlike some asteroids, tend to be on highly elliptical orbits- and thus actually would cost a LOT of Delta-V to get to or capture in Earth orbit...

The Deep Impact spacecraft, along with Rosetta, has successfully rendezvoused with comets, each carrying a bunch of scientific sensors and sub-spacecrafts (an impactor and a lander, respectively). I believe replacing these payloads with ion thrusters along with RTG/solar panels and some propellant wouldn't be much of a challenge, but I may have missed some other considerations.

I was pointing out that In-Situ Resource Utilization (which isn't a thing for many KSP players) is actually likely to become a thing sooner than fuel tankers launched from Earth (which *is* a thing for many KSC players).

Stock KSP does not provide ISRU capabilities to the player. Only modded copies does.

However, I agree that we are more likely to launch fuel refineries rather than tanker spacecrafts in the near future.

And actually, there is already a working Sabatier Reactor on the International Space Station, being used for life-support. It's not much of a stretch to use the same reactor on Mars to make methane for an interplanetary mission's return-trip to Earth... (you send the reactor ahead of the mission, and make the return fuel before the astronauts ever leave Earth...)

...Which is Zubrin's Mars Direct plan, if I recall correctly. I personally find the plan intriguing.

I never heard of the ISS having a Sabatier reactor installed within it before. Interesting fact, I must say.

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