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Active debris removal (harpoon satellites, magnet arms, whatever) are not a solution to this problem and are a huge waste of money. These missions answer the qu

Active debris removal (harpoon satellites, magnet arms, whatever) are not a solution to this problem and are a huge waste of money. These missions answer the question "could one dock with debris and deorbit it?" To which the answer is "obviously yes, but at enormous cost" and you don't need to spend 50M euros to prove it. The answer is exactly what governments and industry have been doing for at least two decades now. Tracking of in-orbit objects, coordinated conjunction response, and rules that require either manual or drag-induced reentry cleanup at the end of a mission. Active maneuverable satellites in orbit (like Starlink) aren't a fundamental problem. The number of objects has gone up significantly, but the big actors are coordinating and following good practices.

mandevil 2y ago
And make sure that even in the most unhappy cases, you vent your tanks! Vent vent vent vent! Tank explosions are where the really nasty debris numbers come from.
- rx_tx 2y ago
  What do you do with the added deltaV from the venting? (not sure if significant) It could send the already-out of control rocket stage/object to a weirder or worse orbit, increasing the changes of collision.
  - mandevil 2y ago
    Ideally you have several vents perpendicular to the orbital path and open them at the same time, so the vectors cancel out. That's the happy case. If, because we are in the sad case, we can't get that, it's still better to have one piece of debris versus thousands.
    - gpm 2y ago
      Shouldn't the happy case be "we know the orientation of the stage so we can vent in the direction we are travelling to accelerate deorbiting"?
  - Filligree 2y ago
    The deltaV will out, one way or the other. Venting is better than having it completely uncontrolled.
  - Evidlo 2y ago
    Vent for a while, then use the reaction wheels to flip and vent in the opposite direction.
- naikrovek 2y ago
  I’ll make sure I remind all of my satellite control room employee relatives. We all will, right?
mschuster91 2y ago
> These missions answer the question "could one dock with debris and deorbit it?" To which the answer is "obviously yes, but at enormous cost" and you don't need to spend 50M euros to prove it. Well, it's not about debris, it's about the capability to sneak up to an enemy satellite and disrupt it without outright destroying it or making it look like a failure. Shooting a satellite with a rocket ("ASAT") is easy enough - the US, China, Russia and India have proven that capability, and Israel likely has it as well. EMPs from nuclear blasts are another option. But either of that leaves undeniable traces (an EMP blast would likely fry a lot of stuff on the ground!) and the debris can endanger your own satellites as well, so you need something that acts in-space, preferably very difficult to observe from Earth. And something that can grab a dead satellite and drag it out of orbit can also just go and deposit a small explosive charge. And at that point, 50 million euros are chump change to test that capability - if needed, replace the magnet/hook/whatever with a bomb and that's it.
- mgiampapa 2y ago
  What's the X-37 cost again? $200M over 4 years of development?
robotomir 2y ago
You can deorbit debris without physical contact, but you could argue the method results in a weapon: https://en.wikipedia.org/wiki/Laser_broom https://en.wikipedia.org/wiki/Laser_broom
- cuSetanta 2y ago
  In-space contactless theories also exist: https://en.wikipedia.org/wiki/Ion-beam_shepherd https://en.wikipedia.org/wiki/Ion-beam_shepherd
- aeternum 2y ago
  Anything that can deorbit debris can be used as an anti-satellite weapon almost by definition.
  - alfiedotwtf 2y ago
    At least talking about it will start the slow expansion of the Overton Window
  - jjk166 2y ago
    It would be an incredibly ineffective weapon. The way a laser broom works is imparting an extremely miniscule bit of momentum every time the object is in line of sight of the laser. Over time you lower its orbit enough for atmospheric drag to take over. For small debris, like baseball sized chunks of insulation, it takes months to deorbit the objects. For something the size of a satellite it would take an order of magnitude longer than the life expectancy of the satellite, and that's assuming it does no station-keeping. Laser brooms are great because they can deorbit a lot of debris in parallel, which is great if your goal is to slowly clean up an orbit. They are pretty much the worst option for deorbiting a specific object quickly which is a hard requirement for any anti-satellite weapon.
    - aeternum 2y ago
      Makes sense but are there actually limits that prevent the scaling? IE instead of a single laser broom I build 50 near a solar/nuclear plant and use the surplus energy. Usually they all deorbit different objects but I could choose to aim them all at the same object. I don't see much of a limit to scale. Satellites can only dissipate so much heat so you don't even have to deorbit it to be successful, you just need impart enough energy to overheat the satellite or disable key parts.
RecycledEle 2y ago
Active debris removal is almost at the level if being an experimental technology. If it works, and if it gets cheaper as the technology matures, it might let use remove derelict satellites before they break up into smaller pieces. It is usually easier to remove a few thousand big pieces of trash than to remove millions of small pieces of trash.
- Aeolun 2y ago
  You just need a very big net.
zamalek 2y ago
> The answer is exactly what governments and industry have been doing for at least two decades now. To a degree. It helps to not blow shit up, in weapons tests or otherwise. These tests arise due to the weaponization of orbit (specifically), so the goal is really to not weaponize orbit - which governments have been doing the exact opposite of. All nations are deciding to tear Solomon's baby to shreds, instead of having shared custody. If people want to weaponize space then, sure, go right ahead. Unless the status quo drastically changes, i.e. bickering old fools being voted out (or removed via other means where voting is not possible/fair) throughout the world, Kessler syndrome is inevitable. I'd wager it happens sooner than runaway global warming.
shakna 2y ago
Starlink have a number of debris problems, including pieces hitting the ground, so I wouldn't say that they're actually following through with their good practices.
- wmf 2y ago
  I thought the pieces hitting the ground are not from Starlink.
- oskarkk 2y ago
  I think that there were no reported cases of Starlink debris hitting the ground (they're designed to burn up in atmosphere). There was a case of SpaceX's Dragon parts hitting the ground lately, but that's a different thing. Also debris hitting the ground is a different issue than debris in orbit, with different problems to solve - you can have a satellite that has 0 chance to hit the ground, while being a serious hazard in space. It's in SpaceX best interest to not leave debris in orbit, because any debris from Starlink would be a threat to Starlink itself.
- try_the_bass 2y ago
  Yeah, none of that is true. Starlink doesn't have a debris problem thanks to the low orbit. Any debris generated deorbit on time-frames of a few months to a free years. Starlink also has 0 reported Earth debris strikes that I can find. Where do you get this misinformation from?
spartanatreyu 2y ago
> Active debris removal (harpoon satellites, magnet arms, whatever) are not a solution to this problem and are a huge waste of money. This is wrong because it's based on a flawed assumption. That assumption being: Propellant is required to deorbit debris, and the rocket equation makes launching all that propellant prohibitively expensive. And while we can't do anything about the rocket equation, we don't actually need to have propellant in space to deorbit things. Ways to deorbit without propellant in space: 1. The ground based methods. Although these would likely be seen by superpowers as military escalation of the status-quo. 2. Propulsion-less drone satellites. All propulsion-less designs use some form of sail which can be used to change the drone's orbit to match the debris before latching on and towing it to a new orbit. Once the debris is now in a decaying or graveyard orbit, the drone can detach and go after it's next target. All that is needed is time, power (readily accessible via solar power this close to the sun), and reaction wheels (which now we know what caused previous designs to fail like in the Kepler mission, can be built to last). The most common form of sails would be solar sails, but there's also EDTs and magnetic sails.
- naikrovek 2y ago
  I would think that solar sails in such an environment would be as bad of an idea as walking through a thick hedgerow in a silk dress. The dress would not survive unscathed, and neither would the solar sail.
  - dredmorbius 2y ago
    A solar sail isn't a pressure vessel, fuel tank, electronics bay, or other sensitive instrument. It can take considerable abuse before being substantially degraded, let alone failing. Space debris impacting on a solar sail would all but certainly simply punch neat holes through it. Much as accumulating dust slowly degrades the light-gathering capability of a large reflector telescope, a modestly-perforated solar sail would lose a very small fraction of its effectiveness. But you could probably lose a heck of a lot of surface area before those effects became significant. Strength of the sail itself is probably a minimal concern, though a design with periodic reinforcing threads (themselves having a cost of increased mass) might be more than sufficient to address any strength compromise.
Log_out_ 2y ago
Ground based laser evaporation to slow debree down?

mandevil 2y ago

And make sure that even in the most unhappy cases, you vent your tanks! Vent vent vent vent! Tank explosions are where the really nasty debris numbers come from.

rx_tx 2y ago
What do you do with the added deltaV from the venting? (not sure if significant) It could send the already-out of control rocket stage/object to a weirder or worse orbit, increasing the changes of collision.
- mandevil 2y ago
  Ideally you have several vents perpendicular to the orbital path and open them at the same time, so the vectors cancel out. That's the happy case. If, because we are in the sad case, we can't get that, it's still better to have one piece of debris versus thousands.
  - gpm 2y ago
    Shouldn't the happy case be "we know the orientation of the stage so we can vent in the direction we are travelling to accelerate deorbiting"?
- Filligree 2y ago
  The deltaV will out, one way or the other. Venting is better than having it completely uncontrolled.
- Evidlo 2y ago
  Vent for a while, then use the reaction wheels to flip and vent in the opposite direction.
naikrovek 2y ago
I’ll make sure I remind all of my satellite control room employee relatives. We all will, right?

mschuster91 2y ago

> These missions answer the question "could one dock with debris and deorbit it?" To which the answer is "obviously yes, but at enormous cost" and you don't need to spend 50M euros to prove it. Well, it's not about debris, it's about the capability to sneak up to an enemy satellite and disrupt it without outright destroying it or making it look like a failure. Shooting a satellite with a rocket ("ASAT") is easy enough - the US, China, Russia and India have proven that capability, and Israel likely has it as well. EMPs from nuclear blasts are another option. But either of that leaves undeniable traces (an EMP blast would likely fry a lot of stuff on the ground!) and the debris can endanger your own satellites as well, so you need something that acts in-space, preferably very difficult to observe from Earth. And something that can grab a dead satellite and drag it out of orbit can also just go and deposit a small explosive charge. And at that point, 50 million euros are chump change to test that capability - if needed, replace the magnet/hook/whatever with a bomb and that's it.

mgiampapa 2y ago
What's the X-37 cost again? $200M over 4 years of development?

robotomir 2y ago

You can deorbit debris without physical contact, but you could argue the method results in a weapon: https://en.wikipedia.org/wiki/Laser_broom https://en.wikipedia.org/wiki/Laser_broom

cuSetanta 2y ago
In-space contactless theories also exist: https://en.wikipedia.org/wiki/Ion-beam_shepherd https://en.wikipedia.org/wiki/Ion-beam_shepherd
aeternum 2y ago
Anything that can deorbit debris can be used as an anti-satellite weapon almost by definition.
- alfiedotwtf 2y ago
  At least talking about it will start the slow expansion of the Overton Window
- jjk166 2y ago
  It would be an incredibly ineffective weapon. The way a laser broom works is imparting an extremely miniscule bit of momentum every time the object is in line of sight of the laser. Over time you lower its orbit enough for atmospheric drag to take over. For small debris, like baseball sized chunks of insulation, it takes months to deorbit the objects. For something the size of a satellite it would take an order of magnitude longer than the life expectancy of the satellite, and that's assuming it does no station-keeping. Laser brooms are great because they can deorbit a lot of debris in parallel, which is great if your goal is to slowly clean up an orbit. They are pretty much the worst option for deorbiting a specific object quickly which is a hard requirement for any anti-satellite weapon.
  - aeternum 2y ago
    Makes sense but are there actually limits that prevent the scaling? IE instead of a single laser broom I build 50 near a solar/nuclear plant and use the surplus energy. Usually they all deorbit different objects but I could choose to aim them all at the same object. I don't see much of a limit to scale. Satellites can only dissipate so much heat so you don't even have to deorbit it to be successful, you just need impart enough energy to overheat the satellite or disable key parts.

RecycledEle 2y ago

Active debris removal is almost at the level if being an experimental technology. If it works, and if it gets cheaper as the technology matures, it might let use remove derelict satellites before they break up into smaller pieces. It is usually easier to remove a few thousand big pieces of trash than to remove millions of small pieces of trash.

Aeolun 2y ago
You just need a very big net.

zamalek 2y ago

> The answer is exactly what governments and industry have been doing for at least two decades now. To a degree. It helps to not blow shit up, in weapons tests or otherwise. These tests arise due to the weaponization of orbit (specifically), so the goal is really to not weaponize orbit - which governments have been doing the exact opposite of. All nations are deciding to tear Solomon's baby to shreds, instead of having shared custody. If people want to weaponize space then, sure, go right ahead. Unless the status quo drastically changes, i.e. bickering old fools being voted out (or removed via other means where voting is not possible/fair) throughout the world, Kessler syndrome is inevitable. I'd wager it happens sooner than runaway global warming.

shakna 2y ago

Starlink have a number of debris problems, including pieces hitting the ground, so I wouldn't say that they're actually following through with their good practices.

wmf 2y ago
I thought the pieces hitting the ground are not from Starlink.
oskarkk 2y ago
I think that there were no reported cases of Starlink debris hitting the ground (they're designed to burn up in atmosphere). There was a case of SpaceX's Dragon parts hitting the ground lately, but that's a different thing. Also debris hitting the ground is a different issue than debris in orbit, with different problems to solve - you can have a satellite that has 0 chance to hit the ground, while being a serious hazard in space. It's in SpaceX best interest to not leave debris in orbit, because any debris from Starlink would be a threat to Starlink itself.
try_the_bass 2y ago
Yeah, none of that is true. Starlink doesn't have a debris problem thanks to the low orbit. Any debris generated deorbit on time-frames of a few months to a free years. Starlink also has 0 reported Earth debris strikes that I can find. Where do you get this misinformation from?

spartanatreyu 2y ago

> Active debris removal (harpoon satellites, magnet arms, whatever) are not a solution to this problem and are a huge waste of money. This is wrong because it's based on a flawed assumption. That assumption being: Propellant is required to deorbit debris, and the rocket equation makes launching all that propellant prohibitively expensive. And while we can't do anything about the rocket equation, we don't actually need to have propellant in space to deorbit things. Ways to deorbit without propellant in space: 1. The ground based methods. Although these would likely be seen by superpowers as military escalation of the status-quo. 2. Propulsion-less drone satellites. All propulsion-less designs use some form of sail which can be used to change the drone's orbit to match the debris before latching on and towing it to a new orbit. Once the debris is now in a decaying or graveyard orbit, the drone can detach and go after it's next target. All that is needed is time, power (readily accessible via solar power this close to the sun), and reaction wheels (which now we know what caused previous designs to fail like in the Kepler mission, can be built to last). The most common form of sails would be solar sails, but there's also EDTs and magnetic sails.

naikrovek 2y ago
I would think that solar sails in such an environment would be as bad of an idea as walking through a thick hedgerow in a silk dress. The dress would not survive unscathed, and neither would the solar sail.
- dredmorbius 2y ago
  A solar sail isn't a pressure vessel, fuel tank, electronics bay, or other sensitive instrument. It can take considerable abuse before being substantially degraded, let alone failing. Space debris impacting on a solar sail would all but certainly simply punch neat holes through it. Much as accumulating dust slowly degrades the light-gathering capability of a large reflector telescope, a modestly-perforated solar sail would lose a very small fraction of its effectiveness. But you could probably lose a heck of a lot of surface area before those effects became significant. Strength of the sail itself is probably a minimal concern, though a design with periodic reinforcing threads (themselves having a cost of increased mass) might be more than sufficient to address any strength compromise.

Log_out_ 2y ago

Ground based laser evaporation to slow debree down?