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Space Junk 
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Post Space Junk
Was paging through the Guardian's science section and this space junk article was on the front page:
Image

http://www.theguardian.com/science/2016/jan/22/rise-in-space-junk-could-provoke-armed-conflict-say-scientists

Does any nation have any real plans for cleaning up all the space junk that is accumulating around our planet? Or are we going to look like this in a few years: Image


Sun Jan 24, 2016 7:44 am
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Post Re: Space Junk
Aren't most of the stuff up there in a slowly decaying orbit anyway?

http://orbitaldebris.jsc.nasa.gov/faqs.html#12

Most orbital debris is around the 300km 700 to 800km height and as such they will inevitably enter earth's atmosphere in a few years decades.

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Sun Jan 24, 2016 8:38 am
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Post Re: Space Junk
But at the rate we're putting things up into space every single year we're at a net positive of junk, are we not?


Sun Jan 24, 2016 8:49 am
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Post Re: Space Junk
Iirc all major space agencies have guidelines for limiting the creation of debris. NASA, ESA, the Russians, Chinese and etc. The problem was that at first no one took the issue seriously and that led to a lot of debris being created in the 80s and 90s; most of which has yet to reach final decaying orbit and won't do so for an other decade or two. The stuff that falls now is from the 70s and even without any control it was less debris than what we produce now (fewer space agencies and launches). Currently the various agencies produce far less debris than the 80 and 90 eras with improvements being made regularly.

In short things will get a little bit more congested up there before the bulk of the debris from the pre-limit era falls on Earth. After that Earth's orbit will get gradually clearer until it levels off.

Practically there isn't anything that space agencies can do about the debris other than to limit it and throw it away in fast decaying orbits. Sending cleaning crews after debris is stupidly expensive and we don't yet have the technology to scoop them up en mass.

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Sun Jan 24, 2016 9:04 am
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Post Re: Space Junk
Grayhome wrote:
But at the rate we're putting things up into space every single year we're at a net positive of junk, are we not?

Thus, the number of new space debris is minimized. Since the main sources of debris in low orbits were the last stage rockets.


Sun Jan 24, 2016 9:36 am
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Post Re: Space Junk
stuffin.space


Sun Jan 24, 2016 11:56 am
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Post Re: Space Junk
dragoongfa wrote:
Aren't most of the stuff up there in a slowly decaying orbit anyway?

http://orbitaldebris.jsc.nasa.gov/faqs.html#12

Most orbital debris is around the 300km 700 to 800km height and as such they will inevitably enter earth's atmosphere in a few years decades.
One of the 70's (or was it 60's?) US projects threw out a bunch of wires/needles to measure something or another. Those are in LEO, but some will presumably be there for as much as a century.

dragoongfa wrote:
Practically there isn't anything that space agencies can do about the debris other than to limit it and throw it away in fast decaying orbits. Sending cleaning crews after debris is stupidly expensive and we don't yet have the technology to scoop them up en mass.
It has actually been suggested that a laser could be mounted to the ISS to speed-up the process. It was referred to as a "laser fence" or broom or something of the sort.


Sun Jan 24, 2016 12:01 pm
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Post Re: Space Junk
Absalom wrote:
One of the 70's (or was it 60's?) US projects threw out a bunch of wires/needles to measure something or another. Those are in LEO, but some will presumably be there for as much as a century.

No objects in low orbits over decades can not survive. If they have no engine to maintain orbit.
And, in general, smaller than the object, the faster it becomes high and burned in the atmosphere.


Mon Jan 25, 2016 11:19 am
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Post Re: Space Junk
hi hi

Earth has a lot of satellites orbiting in a lot of different orbital altitudes, some of which decay slowly, some of which do not. Manned space missions usually take place at 500km or below, because it is safer from debris there, than in the higher altitudes where unmanned satellites are kept. The majority of debris generating satellites in Low Earth orbit (Between 160 and 2000 km), are in a band between 800 km, and 1000 km, and another band around 1500 km. At 1000 km, debris can last for centuries, and at 1500 km, it can last significantly longer. (While gradually raining down on lower orbits as it decays.)

Debris in Medium Earth Orbit (Between 2000 km and 35786 km), especially in the commonly used 12 hour orbital period altitude, are not significantly affected by atmospheric drag.

In reality, the Kessler Syndrome effectively started in 2009, when the Iridium 33 and the Cosmos 2251 satellites collided, at an altitude of 790 km. It is expected to continue and gradually accelerate for at least the next 200 years. So far, no plans to remove debris have been put into action yet.

Debris and Future Space Activities, Prof. Joel R. Primack
The Kessler Syndrome: Implications to Future Space Operations, Donald J. Kessler, Nicholas L. Johnson, J.-C. Liou, Mark Matney
Planet Earth, Space Debris: Bechara J. Saab


Mon Jan 25, 2016 1:24 pm
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Post Re: Space Junk
Life Time in free flight, without correction of the orbit motors of objects in orbit less than 600 km - not more than 10 years. For example, Skylab, with an orbital altitude of 430 km, Coast only lived 5 years.
At altitudes from 600 to 1000 km in the lifetime of the coast - a few decades.
More than 1,000 km to about 30 000 km is located the lower Van Allen Belt, and satellites continued existence at these heights do not fly, or fly in very elongated polar orbit. This is the traditional "dump", which until recently went to the burial of the upper stages of rockets, end up satellites and being similar objects.
The fact that the orbital plane of the system "Iridium" orbits intersect with several dozen other satellites, it was known at the time of system design. It was also estimated that the average probability of collision between - 1 for 10 years or more.
12 years after the deployment of a collision has occurred, confirming the correctness of calculations.

Now the volume of human activity in space are reduced. If the trend changed and the volume of space activity will start to grow, the amount of garbage in the "cesspool" of the lower Van Allen belts might start growing again and will be given "safe route", where littering is prohibited. And it might be a more cost-effective to dump waste into the atmosphere.

Running the program is now "on struggle against space debris" are more similar to international agreements to bypass the ban on creation of systems of anti-satellite weapons and space-based weapons.


Mon Jan 25, 2016 10:38 pm
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Post Re: Space Junk
The most important thing was to ban the explosive destruction of satellites at the end of their life time, as it was done at the start of our space era.
Instead the satellites now need to be either brought down by braking and (partly-)controlled descend into Earth's atmosphere, where they can burn, or be lifted out of near Earth orbit into a parking/garbage orbit.
Which means extra fuel reserve necessary to allow those manoeuvres.

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Tue Jan 26, 2016 6:05 am
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Post Re: Space Junk
You people are calling it a dump, cess pool, waste, personally i am calling it storage. look at all that shiny metal, we get a big enough pile we can use it to build a huge space ship to fly away on.

We need the raw materials up there, and then when we get enough junk, we need to start working on space based manufacturing abilities.

8-) always look on the bright side of life.


Wed Jan 27, 2016 4:50 am
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Post Re: Space Junk
I like that idea. All that mass was expensive to put up there, repair, re-purpose, or recycle it.


Wed Jan 27, 2016 4:56 am
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Post Re: Space Junk
For long term it'll be a great source of metal, for a short while.
If we get facilities up there that can refine metals, this'll be the first source for raw materials.

So, tax money in form of subsidised space lifting and scrap metal for the first company able to use the storage and thus able to claim salvage rights.

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Wed Jan 27, 2016 5:10 am
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Post Re: Space Junk
Disposal of waste is great.
But the mass of the ISS - 150 tons, the mass of the space station - the shipyard should be even greater. The weight of one of the ship to fly humans to Mars for at least 200 tonnes in low Earth orbit. Stocks waste for the production of these things are small.
Although clear orbit the Earth in any way useful, and deploy orbital production of space expansion at rationally. So it is quite possible that our space debris will be recycled.


Wed Jan 27, 2016 6:04 am
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Post Re: Space Junk
It is likely, IF we ever get up there.
But if we'll go and "catch" the smaller waste I doubt. That stuff is fast, and it's small. The energy expenditure to catch that is just not worth it.
Except by building catching armour (impact armour to collect those small particles), but that would be horribly inefficient, waiting to get hit, and hoping no new debris is thrown out of your armour.

So, IMHO only the satellites which have been catapulted as a whole into a debris orbit will be reused.
My grand-kids might know more by the time they're old.

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Wed Jan 27, 2016 7:24 am
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Post Re: Space Junk
In the Soviet automatic interplanetary station "Venera-8" was a bad teammate COSMOS 482 DESCENT CRAFT, which has failed to start a geosynchronous transfer orbit in 1972.
Initially, the apogee of the orbit - 9800 km, today - 2815 km. During the 5 years it is expected to fall to Earth spacecraft.
Below: the top line - height of apogee, bottom line - the height of the perigee.
Image


Sun Feb 21, 2016 1:19 am
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