> To explain how such a disaster would affect life on earth’s surface, Moriba Jah, Associate Professor at the University of Texas at Austin’s School of Aerospace Engineering and Engineering Mechanics, provided a chilling narrative in a Ted Talk (edited here for brevity) ... The most immediate sign to the public would be the sudden failure of broadcast TV. Not long after, travelers and operators would notice that their GPS no longer worked. ...
Kessler syndrome in LEO wouldn't cause any of this. GPS is up at MEO; satellites that are used for communication and TV are mostly up in GEO.
Yeah, it would be much more gradual than this but could happen if LEO were clogged enough to prevent launches. However, many missions (eg camera satellites) are moving toward LEO rather than GEO/MEO.
Could runaway Kessler syndrome in LEO would launch enough debris that some would reach MEO? Though out there the density of debris might not be high enough to pose much risk.
The article glossing over this made me a bit dubious of the whole thing.
The Ted Talk hysteria of "screeching to a halt", as if all the satellites would disassemble in unison was where I stopped...
(Though I like the idea of them all going fractal during the transition to daylight savings time in a country they are immediately overhead to maximize screeching)
The article suggest it would affect all orbits equally but does it? I find it kind of hard to believe LEO will affect MEO as suggested with GPS but I'm not too knowledgeable on this.
Because of overlaps in orbital altitudes and the possibility of weird dynamics causing some fragments reaching a somewhat higher orbit, it's possible that the effects could cascade slightly above the altitude of the original impact event.
The scariest things are a dead object like a rocket stage in GTO hitting the debris field. But even then, substantially all the debris will re-enter in a few months: perigee remains roughly the same.
- Satellites below 500km altitude already have ~5 yr lifetime before re-entry. It is enough to limit mega-constellations to stay below this limit to ensure safety of future operations. Still, the collision probability will increase with the growth of such constellations. Introduction of more automated collision resolution protocol, similar to TCAS in aviation, is at least being discussed.
- Biggest accumulation of debris happen around 800 km altitude, primary from ASAT tests and derelict satellites. Something should be done about this, but salvage operations are not feasible due to lack of regulatory regime. Things will slowly get worse until they hit the rock bottom. Only then we will see some kind of action.
The 25 year requirement isn't a panacea, because deorbit mechanisms are not going to be perfectly reliable decades after launch. They increase the number of satellites you can fly somewhat.
The author appears to be a crank. Judging by the breadth and usual focus of his screeds^W posts, he has no particular insight or special expertise, other than catastrophizing things.
I'm willing to entertain a discussion of the dangers of Kessler syndrome in the near future. But not a crank one.
Every year gets better and better. We have rockets landing on chopsticks and designer vaccines. I wish I could live longer to see where we're going - all the excitement lies ahead of us, and every year is more interesting than the last.
Now, imagine living in Victorian era: electic lights instead of gas and candles, electric motors, engines, trains, steam ships, the refrigerator, the telegraph, the microscope, microbiology and germ theory, sanitation reforms, first anaesthetics, first X-rays.
If you're trying to make a statement about the number of transformative discoveries or the rate of change, I'd disagree.
While progress might appear slower, it's because the low hanging fruit have been plucked and we're working on much harder things.
Autonomous helicopters on Mars and giant 45 degree Kelvin mirrors at LaGrange points are harder than plumbing. Nevermind EUV lithography. Or the previously mentioned rapid drug development.
It's pretty remarkable how far we've come in just the last ten years.
Even the stupid things like endless on-demand entertainment are great. And travel, communication, keeping memories, live entertainment. They didn't have drone shows or voice changing VRChat VTubers.
I'd prefer to live in today's world over the Victorian era. And the coming generations will have it even better.
They talk a lot about low orbit and collisions there - but then suddenly jump to gps disappearing being our first clue a disaster has happened. GPS satellites are thousands of miles out in geostationary orbit.
I’m not going to comment on the plausibility of the scenarios, but I will observe that geopolitically this plays out just like the climate crisis:
There’s a global resource that needs to be managed.
Some countries have a bigger slice than others.
There’s an unhealthy dynamic where the ones with the smaller slice want a bigger slice, but not only do those with a bigger slice not want to give anything up, they point to the ones with the smaller slice growing their share and use it to justify continuing to expand.
Not helped by the fact that many of the parties involved would rather wage war on another if we didn’t all have nukes.
27 comments
[ 2.9 ms ] story [ 69.0 ms ] threadKessler syndrome in LEO wouldn't cause any of this. GPS is up at MEO; satellites that are used for communication and TV are mostly up in GEO.
The article glossing over this made me a bit dubious of the whole thing.
(Though I like the idea of them all going fractal during the transition to daylight savings time in a country they are immediately overhead to maximize screeching)
Because of overlaps in orbital altitudes and the possibility of weird dynamics causing some fragments reaching a somewhat higher orbit, it's possible that the effects could cascade slightly above the altitude of the original impact event.
The scariest things are a dead object like a rocket stage in GTO hitting the debris field. But even then, substantially all the debris will re-enter in a few months: perigee remains roughly the same.
Nothing to blame the poster, mind. The author went for clickbait, so may he be tarred and feathered for it.
- Biggest accumulation of debris happen around 800 km altitude, primary from ASAT tests and derelict satellites. Something should be done about this, but salvage operations are not feasible due to lack of regulatory regime. Things will slowly get worse until they hit the rock bottom. Only then we will see some kind of action.
I'm willing to entertain a discussion of the dangers of Kessler syndrome in the near future. But not a crank one.
While progress might appear slower, it's because the low hanging fruit have been plucked and we're working on much harder things.
Autonomous helicopters on Mars and giant 45 degree Kelvin mirrors at LaGrange points are harder than plumbing. Nevermind EUV lithography. Or the previously mentioned rapid drug development.
It's pretty remarkable how far we've come in just the last ten years.
Even the stupid things like endless on-demand entertainment are great. And travel, communication, keeping memories, live entertainment. They didn't have drone shows or voice changing VRChat VTubers.
I'd prefer to live in today's world over the Victorian era. And the coming generations will have it even better.
(Unless you're counting the few geostationary WAAS satellites).
There’s a global resource that needs to be managed.
Some countries have a bigger slice than others.
There’s an unhealthy dynamic where the ones with the smaller slice want a bigger slice, but not only do those with a bigger slice not want to give anything up, they point to the ones with the smaller slice growing their share and use it to justify continuing to expand.
Not helped by the fact that many of the parties involved would rather wage war on another if we didn’t all have nukes.