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Decluttering low-Earth orbit: It's time to tidy up space

economist.com

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Re: Decluttering low-Earth orbit: It's time to tidy up space

#101

Post by jimmaswell »

tomhoward wrote: post #17

Fun fact: A hobby satellite my father helped build as a way to justify procrastinating during university in the late 60s is now low Earth orbit space junk. He says he's rather embarrassed to have learned, post launch, that it would likely remain in orbit for 100,000 years. https://en.wikipedia.org/wiki/Australis-OSCAR_5 http://centralblue.williamsfoundation.org.au/oscar-5-the-fir... https://www.youtube.com/watch?v=hj…

We'll figure out how to clean it up when or if it's ever a problem. He shouldn't worry about it.

Re: Decluttering low-Earth orbit: It's time to tidy up space

#102

Post by btilly »

charlesju wrote: post #78
bgun wrote: post #52

Earlier quoted context omitted.

That makes the very big assumption that the density of other things to hit doesn’t massively increase.

That makes a big assumption we can't remove the junk before the density is high enough

It is worthy of note that SpaceX is pitching Starship for active debris removal in space.

It is worthy of note from https://spacenews.com/upper-stages-top-list-of-most-dangerou... that in a list of the 50 most concerning objects in orbit, 78% are rocket bodies, and 80% were launched before 2000 when various mitigation strategies for space junk began to be improved.

There is therefore a Pareto principle at work here. We are tracking over 25,000 objects, but only a few of them contribute most of the risk, and we aren't adding as much to the risk as the number of launches would make you think.

Re: Decluttering low-Earth orbit: It's time to tidy up space

#103

Post by napier »

What we need is a fleet of teleoperated VASIMIR-engined trawlers with electromagnetic fishing nets to clean up space garbage. What about funding? A levy on satellite launches and operators under the polluter pays principle. Perhaps this could be structured as an addition to insurance premiums, considering the purpose is perpetuation of access to Earth orbit and outer space for the sake of future generations and for all mankind.

Re: Decluttering low-Earth orbit: It's time to tidy up space

#105

Post by jerf »

f-word wrote: post #89
jerf wrote: post #63

Earlier quoted context omitted.

No, your "mitten" is getting blown apart, not getting progressively stronger. Your intuition is not tuned for space. Imagine trying to strengthen a structure by firing extremely high-powered bullets at it. "I have a tree near my house that is about to fall on us... how should I fire my high-powered rifle at it to reinforce it so it stays up?"

Right, so what's your solution then?

Who says I have a solution? Or that there even is one?

Re: Decluttering low-Earth orbit: It's time to tidy up space

#107

Post by flipflipper »

Symmetry wrote: post #91

One cool way of de-orbiting satellites is to brake against the Earth's magnetic field with a conducting wire. This is actually already a product. https://www.tethers.com/deorbit-systems/

There were couple demo sats launched a few months ago. One with the tether, one without. https://www.dragracersat.com/

Re: Decluttering low-Earth orbit: It's time to tidy up space

#108

Post by hnarn »

laurent92 wrote: post #99
tomhoward wrote: post #17

Fun fact: A hobby satellite my father helped build as a way to justify procrastinating during university in the late 60s is now low Earth orbit space junk. He says he's rather embarrassed to have learned, post launch, that it would likely remain in orbit for 100,000 years. https://en.wikipedia.org/wiki/Australis-OSCAR_5 http://centralblue.williamsfoundation.org.au/oscar-5-the-fir... https://www.youtube.com/watch?v=hj…

> Launch date: 23 January 1970 Phew, 23 days earlier your father would have had to code all timestamps in negative. Joke apart, which OS did such satellites run? Unix? Probably not, since timestamps only started in 1970. Just "C"? Even today, how do you register time on satellites? With Unix timestamps (a long since 1970-01-01)? Can they synchronize based on objective points (stars or Earth position to the sun) or ar…

I have to say that the assumption of a hobbyist satellite in 1970 to be able to run UNIX is pretty amusing, considering (Wikipedia):

> In a 1970 survey, The New York Times suggested a consensus definition of a minicomputer as a machine costing less than US$25,000 (equivalent to $165,000 in 2019), with an input-output device such as a teleprinter and at least four thousand words of memory, that is capable of running programs in a higher level language, such as Fortran or BASIC.

I think it’s safe to say that the biggest issue with launching computers running UNIX into space in 1970 probably was not the lack of a standardized time stamp :-)

Re: Decluttering low-Earth orbit: It's time to tidy up space

#109

Post by crazygringo »

dylan604 wrote: post #66
crazygringo wrote: post #57

Earlier quoted context omitted.

But there's an enormous difference between cosmic dust, which generally doesn't pose any threat to satellites or spacecraft, and the man-made "junk" that are essentially destructive whizzing bullets, cannonballs, and worse. The total mass is essentially irrelevant, what matters is the mass of individual objects. > Or, at least they are in orbits where danger from natural debris is vastly greater than from space junk.…

a rock the size of pebble or as small as a grain of sand will cause a very bad day when you realize that some of the objects have incredible amounts of kinetic energy due to the speeds involved (the speed of the rock or the speed of the thing to be damaged).

But that's the entire point -- fragments of space junk can be the sizes of pebbles you're talking about.

Cosmic dust, on the other hand, is just dust. It can be abrasive but satellites are designed to handle it, as is the ISS. It may have high velocity but the fact that its mass is miniscule means it can be shielded against.

Re: Decluttering low-Earth orbit: It's time to tidy up space

#110

Post by rocknor »

Rebelgecko wrote: post #85
rocknor wrote: post #68

Earlier quoted context omitted.

Meanwhile USA has 25x the debris (as of June 2019). Glass houses... https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv... https://www.businessinsider.in/us-russia-china-and-india-sta...

I think the concern is that despite increased activity in space, most countries have slowed down the amount of dangerous debris being created. Meanwhile, India created about as much space junk in a day as the US creates in 1-2 years. That's despite claiming that the the test was in an orbit that wouldn't leave any longterm debris.

I think you should focus on the huge amount of garbage and carbon emissions produced everyday in the USA (biggest contributor to climate change), which is objectively a much bigger problem than this one-off event which media portrayed as some sort of catastrophe. It's "glass houses" all over again. Why should a nation of 350M people have ASAT capability in the interest of national security, but not a nation of 1.4B people? We're seeing what happens when power is concentrated in the hands of a few (Trump/Parler bans) and it cannot be allowed to happen at a geopolitical level, in the interest of world peace (it sounds crazy but it has worked post WW2).
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