Your first chart actually suggests a dip in debris because the slope in the orange section is not as dramatic as the blue. While the chart seems dramatic, it’s important to note that debris is not maneuverable, and thus contributes much more Kessler risk than maneuverable satellites.
Also this neglects the idea that debris is returning to earth. Debris in low earth orbit (LEO) will naturally fall back to earth at an exponentially faster rate than debris in MEO or GEO.
Debris is obviously a concern, but the surface area of the area 500km above the surface of earth is 4-5x greater than all land on earth. Imagining we space orbital shells apart by 10-100km, you can start to imagine how much actual space there is in Space, and how much good stewardship of the environment is a clear possibility. Hostility or negligence on actors will spoil the environment for all, but in LEO all debris will fall back to earth on a human life time scale and it’s not like we’ve done some irreparable thing to ourselves (not to say it wouldn’t be a huge short term issue though)
Thanks for the comment. I agree the first chart shows a dip in tracked debris. For what it's worth, I believe ESA data suggests an increase, and I'm not sure why they conflict.
Indeed debris returns to Earth, and that's a big reason why I'm not more worried. The altitude even within LEO does matter a fair bit. Decay timescales for <300km are days to weeks, but >600km and it's many years. However, the main concerns considered in the piece are relevant even if debris sticks around for less than a decade, so I don't think it's a decisive consideration.
I also agree there is a lot of space in space. It's too easy to picture a dense cloud of debris, whereas the real picture is an almost entirely empty expanse, with very rare sand-like specks flying at ~10km/s. But this is why I think it's hugely difficult to literally block launches using debris.
Your first chart actually suggests a dip in debris because the slope in the orange section is not as dramatic as the blue. While the chart seems dramatic, it’s important to note that debris is not maneuverable, and thus contributes much more Kessler risk than maneuverable satellites.
Also this neglects the idea that debris is returning to earth. Debris in low earth orbit (LEO) will naturally fall back to earth at an exponentially faster rate than debris in MEO or GEO.
Debris is obviously a concern, but the surface area of the area 500km above the surface of earth is 4-5x greater than all land on earth. Imagining we space orbital shells apart by 10-100km, you can start to imagine how much actual space there is in Space, and how much good stewardship of the environment is a clear possibility. Hostility or negligence on actors will spoil the environment for all, but in LEO all debris will fall back to earth on a human life time scale and it’s not like we’ve done some irreparable thing to ourselves (not to say it wouldn’t be a huge short term issue though)
Thanks for the comment. I agree the first chart shows a dip in tracked debris. For what it's worth, I believe ESA data suggests an increase, and I'm not sure why they conflict.
Indeed debris returns to Earth, and that's a big reason why I'm not more worried. The altitude even within LEO does matter a fair bit. Decay timescales for <300km are days to weeks, but >600km and it's many years. However, the main concerns considered in the piece are relevant even if debris sticks around for less than a decade, so I don't think it's a decisive consideration.
I also agree there is a lot of space in space. It's too easy to picture a dense cloud of debris, whereas the real picture is an almost entirely empty expanse, with very rare sand-like specks flying at ~10km/s. But this is why I think it's hugely difficult to literally block launches using debris.