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It sounds like you're shrugging off the problem, ignoring the advice of experts who are suggesting we need to make changes now and deciding instead that you'll

It sounds like you're shrugging off the problem, ignoring the advice of experts who are suggesting we need to make changes now and deciding instead that you'll ask those same experts to fix the problem later when their predictions come true; allowing intuition, incentives to continue current behavior, and resistance to change to determine your course of action. But intuitions fail when it comes to how mind-bogglingly big and fast space is. The volume you might need to sift through has an area equal to the surface of the entire planet and a height of thousands of kilometers. The objects you're trying to grab are moving at >20,000 km/hr. Low orbits do decay naturally in a few decades, yes, but MEO and GEO orbits can take thousands to millions of years to decay. It's like being a war zone where bullets that are fired continue ricocheting through the air for decades, and these objects are moving ten times faster than a typical bullet (and may weigh hundreds of kg). We're laying a minefield and not even keeping track of where the mines are laid. The least we can do is to keep track of and share the satellite orbits.

didericis 5y ago
I’m not shrugging off the problem, and people should be extremely wary to the point where I think it makes sense to portray the situation as if we would be locked to earth forever if it got out of hand so cleanup is never necessary. However I think people underestimate ingenuity and the ability to solve the cleanup problem if we really have to. I don’t know how much effort has really be invested in hitting that cleanup problem as hard as possible, as most discussion about it currently is theoretical, and there isn’t a lot of financial benefit to researching it. If it starts preventing launches, then the incentives to hit the problem harder increase. It’d obviously be better not to be forced into figuring out whether that problem is solvable, my point is it’s not set in stone that it’s an unsolvable problem, and the incentives are currently such that I don’t think we can consider possible solutions adequately explored.
didericis 5y ago
I think we’re also currently tracking most existing debris fairly comprehensively/that seems to be the part of the problem currently receiving the most attention, and rightfully so. As of right now tracking debris and trying not to create more of it seems like the best way forward
asdfasgasdgasdg 5y ago
The probability of a collision in meo, heo, or geo are also much lower than leo, though, because the volume of these spaces are much, much larger. Low Earth orbits end around 2000km up. Meanwhile geo orbits are around 35000km. That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large. Not that it isn't something we should be concerned about, but especially the higher up you go the more that concern should be tempered by the sheer remoteness of the odds of a collision.
- CrazyStat 5y ago
  > That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large The size of a sphere at geostationary orbit altitude is essentially irrelevant, because the only reason you go to geostationary orbit is to be geostationary, i.e. in a narrow band at the equator. The other 99.9% of your sphere is completely unused.
  - asdfasgasdgasdg 5y ago
    I suppose, but in that case relative velocities between orbiters should be quite low as well.
MichaelGroves 5y ago
> Low orbits do decay naturally in a few decades, yes, but MEO and GEO orbits can take thousands to millions of years to decay. Tens of years? Try tens of months. The ISS has a minimum mean altitute of 370 km, a max of 460 km, and within those parameters loses about 2 km per month. But the lower it gets, the faster it falls. When it's on the lower end of it's range, it falls about 3 km per month and that would accelerate rapidly if allowed to go lower. As it is, the ISS is boosted several times a year; five times this year so far: https://www.heavens-above.com/IssHeight.aspx https://www.heavens-above.com/IssHeight.aspx They can go as long as a few months without boosts, but not much longer than that. Not tens of years. The ISS is big and draggy, but the situation isn't much different for smaller satellites in similar orbits. Two test satellites for Starlink, Tintin A and B, were launched to about 500km in 2018. Both have subsequently burned up in the atmosphere after less than three years: https://www.n2yo.com/satellite/?s=43216 https://www.n2yo.com/satellite/?s=43216 > It sounds like you're [...] ignoring the advice of experts Heh, forgive me for this but it seems like you have some half-baked ideas about Kessler syndrome you gleaned from popsci media. The reality is not so simple, nor as extreme, as you've made it out to be. Your estimates for LEO are about an order of magnitude off.

didericis 5y ago

I’m not shrugging off the problem, and people should be extremely wary to the point where I think it makes sense to portray the situation as if we would be locked to earth forever if it got out of hand so cleanup is never necessary. However I think people underestimate ingenuity and the ability to solve the cleanup problem if we really have to. I don’t know how much effort has really be invested in hitting that cleanup problem as hard as possible, as most discussion about it currently is theoretical, and there isn’t a lot of financial benefit to researching it. If it starts preventing launches, then the incentives to hit the problem harder increase. It’d obviously be better not to be forced into figuring out whether that problem is solvable, my point is it’s not set in stone that it’s an unsolvable problem, and the incentives are currently such that I don’t think we can consider possible solutions adequately explored.

didericis 5y ago

I think we’re also currently tracking most existing debris fairly comprehensively/that seems to be the part of the problem currently receiving the most attention, and rightfully so. As of right now tracking debris and trying not to create more of it seems like the best way forward

asdfasgasdgasdg 5y ago

The probability of a collision in meo, heo, or geo are also much lower than leo, though, because the volume of these spaces are much, much larger. Low Earth orbits end around 2000km up. Meanwhile geo orbits are around 35000km. That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large. Not that it isn't something we should be concerned about, but especially the higher up you go the more that concern should be tempered by the sheer remoteness of the odds of a collision.

CrazyStat 5y ago
> That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large The size of a sphere at geostationary orbit altitude is essentially irrelevant, because the only reason you go to geostationary orbit is to be geostationary, i.e. in a narrow band at the equator. The other 99.9% of your sphere is completely unused.
- asdfasgasdgasdg 5y ago
  I suppose, but in that case relative velocities between orbiters should be quite low as well.

MichaelGroves 5y ago

> Low orbits do decay naturally in a few decades, yes, but MEO and GEO orbits can take thousands to millions of years to decay. Tens of years? Try tens of months. The ISS has a minimum mean altitute of 370 km, a max of 460 km, and within those parameters loses about 2 km per month. But the lower it gets, the faster it falls. When it's on the lower end of it's range, it falls about 3 km per month and that would accelerate rapidly if allowed to go lower. As it is, the ISS is boosted several times a year; five times this year so far: https://www.heavens-above.com/IssHeight.aspx https://www.heavens-above.com/IssHeight.aspx They can go as long as a few months without boosts, but not much longer than that. Not tens of years. The ISS is big and draggy, but the situation isn't much different for smaller satellites in similar orbits. Two test satellites for Starlink, Tintin A and B, were launched to about 500km in 2018. Both have subsequently burned up in the atmosphere after less than three years: https://www.n2yo.com/satellite/?s=43216 https://www.n2yo.com/satellite/?s=43216 > It sounds like you're [...] ignoring the advice of experts Heh, forgive me for this but it seems like you have some half-baked ideas about Kessler syndrome you gleaned from popsci media. The reality is not so simple, nor as extreme, as you've made it out to be. Your estimates for LEO are about an order of magnitude off.