Space Junk; What will we do about it?

[tater]

What matters is particle mass (bolt vs paint chip), but also, and more importantly, the relative velocity. The benefit of parking orbits for GEO stuff, aside from simple practicality, is that the closing velocity of any collision in that region will be minuscule. The collisions shown in the video is LEO, and polar. This is a much worse situation, as all the polar stuff crosses everything else at the same altitude 2X per orbit. This is the debris of primary concern. GEO? Far less important with parking orbits (and BEO stuff avoids it because those missions are heading for places in a different plane than the Earth's equator, anyway).

LEO stuff could use with a cleanup, obviously, and perhaps we should work on some of the most promising mitigation schemes.

Edited March 2, 2017 by tater

[kerbiloid]

Even if we'll organize orbits in stages as in aviation (say, 200..210 km, 210..220, etc), the orbiters will bunch up in their intersections like the aircrafts near airports. 

An orbiting object passes through that bunch place every 1.5 hours, exactly like typical plane does.

If let the orbits stay "non-staged" like now, that would just make every orbiter to cross several ranges every turn, which is even much worse.

1 hour ago, tater said:

What matters is particle mass

Size mass doesn't matter! An anti-tank kinetic projectile weights 0.1..5 kg and has more or less the same speed relative to target.
And sats and ships are much less tough than a tank.

[tater]

31 minutes ago, kerbiloid said:

Even if we'll organize orbits in stages as in aviation (say, 200..210 km, 210..220, etc), the orbiters will bunch up in their intersections like the aircrafts near airports. 

An orbiting object passes through that bunch place every 1.5 hours, exactly like typical plane does.

If let the orbits stay "non-staged" like now, that would just make every orbiter to cross several ranges every turn, which is even much worse.

I'm talking about GEO. They don't pass through anything.

31 minutes ago, kerbiloid said:

Size mass doesn't matter! An anti-tank kinetic projectile weights 0.1..5 kg and has more or less the same speed relative to target.
And sats and ships are much less tough than a tank.

Mass matters linearly, relative velocity matters as the square of that velocity.

[kerbiloid]

6 minutes ago, tater said:

Mass matters linearly

While it's less than a bullet mass.
Since it's 0.50 bullet mass (i.e. >= 100 g), it will penetrate any spacecraft through.
Since it's an anti-tank projectile mass, it would be not much difference, is it 10 kg or 10 t.

So, unlike the aviation, we must treat any orbital chunk of junk as a full-featured member of the air orbital traffic with its own place in the separation scheme.

Edited March 2, 2017 by kerbiloid

[YNM]

8 hours ago, Camacha said:

There is something called Big Sky. It is what aviation depended on to prevent collisions before controlled air space. The sky is so incredibly huge and aircraft are so very tiny, that collisions are mathematically impossible. Yet they happened, and kept happening more and more. Before that, humans followed the same thought process when it comes to the pollution of sea and air. They are vast expanses of water and air. It is absolutely impossible that these tiny trickles of pollutants have any effect. In all those cases, our reasoning also happened to be the most convenient way of dealing with the matter. My little drop in the ocean will not do us in. Yet in all cases, we were utterly wrong.

If anything, they clearly didn't exist either in the "old ways". Airports are the places where these things happened the most (mind the prevalence of descent/climb/approach/low level over cruise). Other times, it's within an airway (or well, two).

While this is also true for most satellites (some orbits are more preferred than others), most of these cluttered orbits are either low enough that drag overrule their existence, or is high enough that nudging them a little bit will make a big difference. I have to admit this will make SSO looks the most dangerous, but I think it already is now.

So, if anything, some orbits needs more governance over the others.

[kerbiloid]

13 minutes ago, YNM said:

Airports are the places where these things happened the most (mind the prevalence of descent/climb/approach/low level over cruise). Other times, it's within an airway (or well, two).

Airports aren't the only "bunch places". Airways are not chaotic _{they are lawful!}, their intersections have exact places and five-letter easy-to-pronounce codes (periodically published in the Jeppesen's almanach).
_{Like LAPAK, ITANA, BARUN, etc}

(Don't confuse with airport IATA codes).

These intersections are much more numerous than airports, and aircrafts pass by each other in these points, too.

https://www.google.ru/search?q=flight+plan+five+letter+waypoint&newwindow=1&biw=1920&bih=981&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi88er_lbfSAhUBIpoKHRDOBwQQ_AUIBigB

Edited March 2, 2017 by kerbiloid

[Nibb31]

People are discussing this as if nobody was doing anything about it. In fact there already is strong governance in place for the most crowded orbits. GEO slots are strongly regulated and you don't get one without filling out the requirements for disposal of your satellite. In GEO, everyone is travelling in the same direction and the same speed, and everyone is sticking to their assigned longitude, so the risk of a collision is low. Even if a bird dies before it's boosted to its graveyard orbit, then the risk of collision remains low. If there ever was a collision in GEO, it would be at a very low speed, therefore it wouldn't cause generate much in terms of debris. Any debris would either remain at the same speed, or fly off into a different orbit.

As for LEO, drag clears up most of the debris. This is why the ISS is in LEO, because it's much safer.

The risks are in higher orbits, between LEO and GEO, but there are much less sats out in that space, so the likelihood of a collision is low.

Also, those pics of the Earth surrounded by a cloud of debris are wildly exaggerated. Every dot is blown up to the size of a major city, which makes it seem much worse than it is. In reality, each most dots are smaller than a refrigerator and you definitely wouldn't see them on the graphic.

 

 

[hms_warrior]

Allready work-in-progress:

http://www.esa.int/Our_Activities/Space_Engineering_Technology/Clean_Space

[YNM]

5 hours ago, kerbiloid said:

Airports aren't the only "bunch places". Airways are not chaotic _{they are lawful!}, their intersections have exact places and five-letter easy-to-pronounce codes (periodically published in the Jeppesen's almanach).
_{Like LAPAK, ITANA, BARUN, etc}

(Don't confuse with airport IATA codes).

These intersections are much more numerous than airports, and aircrafts pass by each other in these points, too.

I know. I was just saying that, aviators back then certainly knew when aircraft becomes more abundant, big sky can't be applied, because there are only limited amount of places airplanes would go to / came from. Courses already exists since the earliest flights (sometimes following a geographical / prominent feature or so). The post I replied to more or less stated that only after the collisions occur we realized that big sky can't be applied. I wanted to reply that it must have been much earlier than that - probably when we start having some airliners and some interconnecting airports. Navigational aids would be even earlier - World War comes to mind. Even so, thanks to lack of actual positioning of the aircraft, collisions still occur, until today, where controller know exactly where everyone is (or put some gap between traffic), almost all mishap happens for one plane only, and mid-air collision is a rare case.

Edited March 2, 2017 by YNM

[PakledHostage]

3 hours ago, YNM said:

I know. I was just saying that, aviators back then certainly knew when aircraft becomes more abundant, big sky can't be applied, because there are only limited amount of places airplanes would go to / came from. Courses already exists since the earliest flights (sometimes following a geographical / prominent feature or so). The post I replied to more or less stated that only after the collisions occur we realized that big sky can't be applied.

Indeed. It is widely acknowledged that the 1956 mid-air collision between two airliners over the Grand Canyon (https://en.m.wikipedia.org/wiki/1956_Grand_Canyon_mid-air_collision) was the catalyst for developing / modernizing the air traffic control system in the USA and ultimately around the world. That collision happened outside of controlled airspace and off airways where pilots were expected to "see and avoid" other traffic.

Edited March 2, 2017 by PakledHostage

[YNM]

42 minutes ago, PakledHostage said:

That collision happened outside of controlled airspace and off airways where pilots were expected to "see and avoid" other traffic.

Today, we still have oceanic clearance. Pretty much the same, but airplanes enterance are well-planned, and is almost always in IFR. (that collision involved VFR aircraft - IFR means you can still use dead reckoning to tell where everyone is.)

 

Anyway, enough OffTopic.

Edited March 2, 2017 by YNM

[PakledHostage]

11 hours ago, YNM said:

Anyway, enough OffTopic.

It isn't so much off topic as an analogous topic. Airspace is big, aircraft are comparatively small, yet we still have air traffic control systems to keep them apart.

As you point out, we use a system of flex tracks and fixed tracks to control who's flying where and when outside of radar coverage. This mostly keeps aircraft safely separated, but there are still backups to ATC (i.e. TCAS) and even then accidents still happen (i.e. the crash near Bodensee about 10 years ago).

What is an off topic aside is that, in some ways, our current system is more dangerous than it used to be because the accuracy of everybody's navigation has improved to the point where everyone is flying straight down the centreline of their assigned airway. In the pre-GNSS days, the accumulated error in everyone's INS' introduced a bit of scatter which correspondingly reduced the likelihood of collisions due to a mistaken or misunderstood clearance.

Edited March 3, 2017 by PakledHostage

[YNM]

On 3/3/2017 at 8:04 AM, PakledHostage said:

It isn't so much off topic as an analogous topic. Airspace is big, aircraft are comparatively small, yet we still have air traffic control systems to keep them apart.

As you point out, we use a system of flex tracks and fixed tracks to control who's flying where and when outside of radar coverage. This mostly keeps aircraft safely separated, but there are still backups to ATC (i.e. TCAS) and even then accidents still happen (i.e. the crash near Bodensee about 10 years ago).

What is an off topic aside is that, in some ways, our current system is more dangerous than it used to be because the accuracy of everybody's navigation has improved to the point where everyone is flying straight down the centreline of their assigned airway. In the pre-GNSS days, the accumulated error in everyone's INS' introduced a bit of scatter which correspondingly reduced the likelihood of collisions due to a mistaken or misunderstood clearance.

Airplanes can maneuver around, while orbiting debris can't by it's own. If there's anything common, it's that both airplanes and satellites (active ones) have preferred paths over all the other possible.

Mistaken clearance... Well, that's human error... I don't know, don't tracks are assigned right into the FIS nowadays ?

Edited March 4, 2017 by YNM

[WinkAllKerb'']

https://en.wikipedia.org/wiki/Saturn#Planetary_rings

"   ... There are two main hypotheses regarding the origin of the rings.  ... " ... me say: keppler "debris" (whatever the debris come from and are made of ) + lot lot lot of time = "equatorial"(prolly more main body / system center orbit axis equilibirum intersection related in fact <= wich may slighty impact the ring config depending the main body initial orbit within the system) rings per small force addition over time (( @system center + @main body rotation + @both axis + @balanced plan state in the end ))

- sure from a 0 to 100 150 lifspan p.o.v. it may sound problematic, but in fact at larger time scale imho not really (( a 1850-2000 industrial and tech revolution and let's try crazy trial and error things in "the" urge no matter what afterward ((( *§* ))) ))

Edited March 4, 2017 by WinkAllKerb''
*grumpf*

[YNM]

The problem with kessler syndrome is not only the density. It's also about varied orbital plane and eccentricity. Of which all the main Jovian rings doesn't have - most paths are circular and in one main plane.

On the other hand, our satellites have various orbital planes and eccentricities.

Edited March 4, 2017 by YNM

[WinkAllKerb'']

focusing more and more acurate monitoring, and spending a very high attention not adding more to the whole current mess, is may be the best energy pool sources conservation option, and let saturn ring phenomenom doing the debris ring in very very very (veryveryveryveryvery) later ... may be, at least it's seem legit to think that as time goes monitoring should get better and better with the smallest object, while whatever the way recovering the junk is a ressources sink

"short" & "short+" term fears // medium & long term choice regarding finite energy pool

to me it's quite obvious (some may say it's heretic) saturn ring plane state is the result of small force addition over very long period of time

referential 1: universe 
referential 2: a system
rotation + centrifugation // distance // infinitesimal mass attraction @closest proximity and main system body tend to bring thing in this plane whatever the original orbit (it may be hardly mathematically modelisable, or quantifiable) but the principle is fairly simple over long period of time

(it like's  saying galaxy ar brought to the main universe plane // universe center)
(system are brought to this plane via the galaxy barycentre and eventually one of the few very close galaxy in some very rare case)
(planet act the same with there system center)
( and it work as well for a ring after a collision or whatever)

(the sole thing that impact is closest bodies at each others, referential and there mass // center mass and  relative distance, then it's about steps between referential smaller and smaller, or bigger and bigger, wich bring slowly thing to this plane (and while in certain condition i suspect there system/referential inertia constant related to closest center mass  and a celestial bodies mass within the system that impact the said stabilisation timespan a logarithmic way too close in certain condition and mass difference not enough, stabilisation to the main universe plane gonna take ages )

but as it's a slow process, and we do not observe for that long ... ... ... still the whole principle and main mechanics is simple

Edited March 4, 2017 by WinkAllKerb''