3 ms·

If the area above the earth is many orders of magnitude larger than the earth’s oceans, and the oceans are vast in the extreme, what really are the chances of a

If the area above the earth is many orders of magnitude larger than the earth’s oceans, and the oceans are vast in the extreme, what really are the chances of a collision given the relatively small amount of debris in orbit? One can easily find a debris map online. Compared to say “ships in the ocean” the number of “satellites in orbit” must be tiny. And the ships exist on a 2D surface, so are that much more likely to collide. With 3D to move in and such a vast area, what is the actual risk? To be clear I’m not saying there is no risk and I know about cascading debris collapse. I just doubt the whole thing, I’d really like to know if anyone has done the math here.

skinner927 3y ago
Orbits degrade over time. A defunct satellite out of propellant has no guarantees to “stay in its lane”. Space debris are already an issue and we’ve only been putting things in space ~66 years. Imagine if every ship to ever sail was still afloat and never sank. We’d have thousands of unmanned, uncontrollable vessels ping-ponging around the ocean.
Rebelgecko 3y ago
The number of satellites is less than the number of oceangoing ships, but satellites are on track to be ahead in the next decade or so. Then if you start counting every single piece of debris a satellite can run into, you're looking at millions of objects. Unlike ships, the debris (and even many satellites) doesn't have anyone "on watch" and there's no way to steer out of the way at the last minute. Because of how orbits work you can't really organize traffic into "shipping lanes". If you want to do the math yourself, NORAD publishes satellite orbital parameters, which can be used to look for potential conjunctions. You can also sign up for an account at https://www.space-track.org https://www.space-track.org to see the Space Force's data, or CelesTrak for something similar that isn't login-walled (https://celestrak.org/SOCRATES/ https://celestrak.org/SOCRATES/). The tl;dr is that it's not rare for 2 satellites (or a satellite+debris) to have a 1 in 10,000 chance of crashing into each other. As more and more satellites go up and more and more "1 in 10,000" events happen on a daily basis, more conjunctions will occur. Each conjunction can create thousands of pieces of debris, which exacerbates the problem- nowadays I think ~30% of all debris in LEO comes from China's 2007 ASAT test.

skinner927 3y ago

Orbits degrade over time. A defunct satellite out of propellant has no guarantees to “stay in its lane”. Space debris are already an issue and we’ve only been putting things in space ~66 years. Imagine if every ship to ever sail was still afloat and never sank. We’d have thousands of unmanned, uncontrollable vessels ping-ponging around the ocean.

Rebelgecko 3y ago

The number of satellites is less than the number of oceangoing ships, but satellites are on track to be ahead in the next decade or so. Then if you start counting every single piece of debris a satellite can run into, you're looking at millions of objects. Unlike ships, the debris (and even many satellites) doesn't have anyone "on watch" and there's no way to steer out of the way at the last minute. Because of how orbits work you can't really organize traffic into "shipping lanes". If you want to do the math yourself, NORAD publishes satellite orbital parameters, which can be used to look for potential conjunctions. You can also sign up for an account at https://www.space-track.org https://www.space-track.org to see the Space Force's data, or CelesTrak for something similar that isn't login-walled (https://celestrak.org/SOCRATES/ https://celestrak.org/SOCRATES/). The tl;dr is that it's not rare for 2 satellites (or a satellite+debris) to have a 1 in 10,000 chance of crashing into each other. As more and more satellites go up and more and more "1 in 10,000" events happen on a daily basis, more conjunctions will occur. Each conjunction can create thousands of pieces of debris, which exacerbates the problem- nowadays I think ~30% of all debris in LEO comes from China's 2007 ASAT test.