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The Kessler Syndrome: Space junk in orbit

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Re: The Kessler Syndrome: Space junk in orbit

#31

Post by Eelongate »

Kye wrote: post #16
giantg2 wrote: post #5

So where's the "ecological" part? There is no ecology to wreck. There are concerns about the metallic dust from burning up on reentry, but no mention of it in this article.

Merriam-Webster on ecology: "a branch of science concerned with the interrelationship of organisms and their environments" Humans are organisms. Humans go to space, and will go there more with it getting cheaper. Orbital space is an environment. Debris collisions are an ecological concern for spacefaring organisms.

That's a usefully expansive definition of ecology. Next time somebody in my household forgets to put the toilet seat down, I'm going to lodge an 'ecological' complaint with them. After all, I am an organism and bathrooms are an environment; it ticks all the boxes.

Less snark: I think definition (or more accurately, your expansive interpretation of it) misses the spirit of the way that word is generally used.

Re: The Kessler Syndrome: Space junk in orbit

#32

Post by bryanlarsen »

gooseus wrote: post #24
modeless wrote: post #13

The solution for this problem is relatively simple. Satellites should be put in very low orbits. A satellite collision in high orbit is practically irreversible and will pollute space essentially forever. A satellite collision in low orbit is automatically cleaned up by the atmosphere, over a period of years to months to days depending on the orbit height. In the past it was not practical to put satellites in low orb…

I'd be interested in seeing a deep dive analysis comparing the costs in energy / environmental impact, as well as risk profiles from space debris of maintaining clouds of lower-earth orbit satellite vs constellations of higher-earth orbit satellites. For the lower orbits I think there are some points to be made about the additional flights to maintain enough satellites, as well as the questions of what happens to all…

modeless answered one of your questions well, the other has a good deep dive here: lhttps://everydayastronaut.com/rocket-pollution/

A rocket launch powered by fossil fuels is comparable to an oceanic jet trip, surprisingly. So quantities aren't a big deal, yet. Elon Musk has promised to switch to carbon neutral fuel for his next generation of rockets, synthetic methane for Starship.

Re: The Kessler Syndrome: Space junk in orbit

#33

Post by giantg2 »

Kye wrote: post #16
giantg2 wrote: post #5

So where's the "ecological" part? There is no ecology to wreck. There are concerns about the metallic dust from burning up on reentry, but no mention of it in this article.

Merriam-Webster on ecology: "a branch of science concerned with the interrelationship of organisms and their environments" Humans are organisms. Humans go to space, and will go there more with it getting cheaper. Orbital space is an environment. Debris collisions are an ecological concern for spacefaring organisms.

Generally ecology requires multiple species in interrelationship. Not really an ecosystem without inter play between organisms (species) and the environment. I also don't see classes being taught covering space ecology, so I don't feel it fits.

Re: The Kessler Syndrome: Space junk in orbit

#34

Post by simonh »

gooseus wrote: post #24
modeless wrote: post #13

The solution for this problem is relatively simple. Satellites should be put in very low orbits. A satellite collision in high orbit is practically irreversible and will pollute space essentially forever. A satellite collision in low orbit is automatically cleaned up by the atmosphere, over a period of years to months to days depending on the orbit height. In the past it was not practical to put satellites in low orb…

I'd be interested in seeing a deep dive analysis comparing the costs in energy / environmental impact, as well as risk profiles from space debris of maintaining clouds of lower-earth orbit satellite vs constellations of higher-earth orbit satellites. For the lower orbits I think there are some points to be made about the additional flights to maintain enough satellites, as well as the questions of what happens to all…

They’re all interesting points, but I think we’re a very long way from the satellite industry being a significant environmental concern.

Firstly reusable rockets cut the amount of discarded hardware massively. With expendable launchers almost all of the hardware dropped into the ocean or burned up is from the launcher. The satellite is a tiny fraction. This is a huge win.

Secondly the total mass of satellite hardware burning up is dwarfed by natural meteorites, of which approximately 100 tons of silicates, metals and hydrocarbons enters our atmosphere every day. That’s an entire ISS every 4 days. That’s 600 times the mass of satellites the US launches per year.

The thing is Starship may well increase mass to orbit by that much. Even so, that would “only” double the natural rate of material entering the atmosphere.

Another strategy that might help, for high altitude satellites, would be to move to fewer bigger satellites, with racks for different companies instruments, and with self de-orbit capability. Treat them like orbiting data centres. Starship can certainly handle big satellites, and if launches are cheap then it could be affordable to fit such satellites with de-orbit capability. Or maybe even send a Starship to swallow it up and bring it back.

Re: The Kessler Syndrome: Space junk in orbit

#35

Post by giantg2 »

sscept wrote: post #18
giantg2 wrote: post #5

So where's the "ecological" part? There is no ecology to wreck. There are concerns about the metallic dust from burning up on reentry, but no mention of it in this article.

Sentinel-6, GRACE-FO, ICESat-2 are among only a few of the many numerous LEO observational satellites that are at risk should a Kessler syndrome occur... our ability to watch and build predictive models of what's going on with our ecology can/will be lost; this is a huge added problem to the ongoing global ecological collapses and affects our ability to mitigate climate change Not to mention all the communications sy…

This article is focused on LEO. Many of these satellite uses can be achieved in MEO or even HEO.

Re: The Kessler Syndrome: Space junk in orbit

#38

Post by YossarianFrPrez »

pdonis wrote: post #21
YossarianFrPrez wrote: post #12

> History would suggest we’ll screw this up. Space is a commons, and we humans have a terrible track record of despoiling commons. The question isn't "Will there eventually be some sort of incentive to clean up space junk?" (which would lead to some sort of free-market amelioration if not solution), it's "Can this be prevented?" Free market solutions to cleaning up commons often come too late and are imperfect. The o…

> Free market solutions to cleaning up commons often come too late and are imperfect. In this case, the commons, if Kessler's predictions are correct, will become unusable much more quickly than has been the case with other commons in the past. That creates a much stronger free market incentive to clean the commons up.

Indeed. But wouldn't it be nice if we could get our collective act together and not have to clean the commons up in the first place?

Re: The Kessler Syndrome: Space junk in orbit

#39

Post by [deleted] »

Eelongate wrote: post #31
Kye wrote: post #16

Earlier quoted context omitted.

Merriam-Webster on ecology: "a branch of science concerned with the interrelationship of organisms and their environments" Humans are organisms. Humans go to space, and will go there more with it getting cheaper. Orbital space is an environment. Debris collisions are an ecological concern for spacefaring organisms.

That's a usefully expansive definition of ecology. Next time somebody in my household forgets to put the toilet seat down, I'm going to lodge an 'ecological' complaint with them. After all, I am an organism and bathrooms are an environment; it ticks all the boxes. Less snark: I think definition (or more accurately, your expansive interpretation of it) misses the spirit of the way that word is generally used.

[deleted]

Re: The Kessler Syndrome: Space junk in orbit

#40

Post by jaytaylor »

modeless wrote: post #13

The solution for this problem is relatively simple. Satellites should be put in very low orbits. A satellite collision in high orbit is practically irreversible and will pollute space essentially forever. A satellite collision in low orbit is automatically cleaned up by the atmosphere, over a period of years to months to days depending on the orbit height. In the past it was not practical to put satellites in low orb…

Phased array antennas, for the uninitiated:

https://www.google.com/search?q=phased+array+antenna

Basically antennas that can programmatically steered without physically moving.

> In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas.

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