Idina Menzel will clean up space junk??

[JediFragger]

On 3/24/2021 at 2:09 AM, Jtalk4456 said:

Idina Menzel

That's easy for you to say, not so much for John Travolta

[CarlBar]

10 hours ago, Jtalk4456 said:

I will say though that this particular plan involves adding a matching magnet to any future spacecraft,

 

Somehow missed this , cheers for pointing it out. Any yes materials have wildly varying properties, in the real world there's very few free lunches, if a material appears to have huge advantages over another then generally, (not allways, new alloys shake things up all the time for one example, but as a rule of thumb it's good), that means it's got a weakness somwhere else. Now depending on the use case that weakness may not matter very much, but in other use cases it matters a lot. Sometimes the negetive might not matter from a use case PoV but may make manufacturing very difficult due to limitations on machining, casting, welding, e.t.c. Sometimes straight up cost can be an issue if it involves expensive elements or manufacturing techniques, (the later is a big reason Titanium isn't used in more places, it's so reactive at casting temperatures that it require inert atmospheres, and it's a huge pain to machine on any kind of scale, it still has material property issues in some applications compared to steel, but manufacturing issues limit it even beyond that).

[FRD]

Idina Menzel:

"The cold never bothered me anyway

...

But the junk in space does"

[Bombastinator]

On 4/10/2021 at 9:42 AM, CarlBar said:

 

Somehow missed this , cheers for pointing it out. Any yes materials have wildly varying properties, in the real world there's very few free lunches, if a material appears to have huge advantages over another then generally, (not allways, new alloys shake things up all the time for one example, but as a rule of thumb it's good), that means it's got a weakness somwhere else. Now depending on the use case that weakness may not matter very much, but in other use cases it matters a lot. Sometimes the negetive might not matter from a use case PoV but may make manufacturing very difficult due to limitations on machining, casting, welding, e.t.c. Sometimes straight up cost can be an issue if it involves expensive elements or manufacturing techniques, (the later is a big reason Titanium isn't used in more places, it's so reactive at casting temperatures that it require inert atmospheres, and it's a huge pain to machine on any kind of scale, it still has material property issues in some applications compared to steel, but manufacturing issues limit it even beyond that).

Interesting.  I thought the big problem was until recently the only country that could produce it in quantity was the Soviet Union.  They made a whole submarine line out of it once that was nicknamed “the golden fish”.

 

Materials cost is generally trump by lift weight cost though, and the lightweight materials aren’t ferrous. 

[CarlBar]

6 hours ago, Bombastinator said:

Interesting.  I thought the big problem was until recently the only country that could produce it in quantity was the Soviet Union.  They made a whole submarine line out of it once that was nicknamed “the golden fish”.

 

Materials cost is generally trump by lift weight cost though, and the lightweight materials aren’t ferrous. 

 

It's been producible in quantity for some time and heavily used in the aerospace industry for long before the soviet union fell. (The DC 10's engines used titanium fan disks for example). The soviet Union had more of the raw ore, but it's a real pain to refine and turn into useful products as it all has to be done in an inert atmosphere, (and for parts of the process you need a zero moisture environment, (it's a minimum 3 step process from raw ore to pure titanium, then another step to get an alloy)), even as an alloy you can't use it around pure oxygen or other strong oxidisers as it will auto ignite if the oxide layer gets scraped off.

 

As a sort of reverse example of the problems you can run into; when radiation hardening the Juno probe they built the shielding around the electronics out of titanium because the preferred lead, (probably a volume thing, Jupiter has a really rough radiation around it so you need serious shielding and titanium whilst less heavy for a given level of shielding is also way more voluminous), wouldn't handle the launch G's without deforming.

 

Your not wrong that lighter materials will be preferred, but remember rockets also have volume limits to their pay,loads and in many cases the cost is primarily per launch not per kg. there's going to be cases where the volume density or the carry capacity of the rocket vs the satellite mass makes going with steel desirable. basically your right that non-ferrous will be first choice for most things. But there's a ton of edge cases where other materials are good.

[Zulu-Cheese-Alpha-IV]

There is barely any junk out there, they seem to be misunderstanding the vastness of the incomprehensible.

[Bombastinator]

50 minutes ago, Zulu-Cheese-Alpha-IV said:

There is barely any junk out there, they seem to be misunderstanding the vastness of the incomprehensible.

This was discussed earlier in the thread.  This seems to be about predictability of orbits. Just one collision can apparently cause a major knock on effect and tiny objects with uncertain paths become effectively much larger for purposes of safety.  Satellites are really expansive and travel incredibly fast.  At speeds where spitballs can kill.  Safety margins have to be high.  Or something.  If there are a bunch of people saying the math works I suspect it works.  

Edited April 12, 2021 by Bombastinator

[Bombastinator]

56 minutes ago, CarlBar said:

 

It's been producible in quantity for some time and heavily used in the aerospace industry for long before the soviet union fell. (The DC 10's engines used titanium fan disks for example). The soviet Union had more of the raw ore, but it's a real pain to refine and turn into useful products as it all has to be done in an inert atmosphere, (and for parts of the process you need a zero moisture environment, (it's a minimum 3 step process from raw ore to pure titanium, then another step to get an alloy)), even as an alloy you can't use it around pure oxygen or other strong oxidisers as it will auto ignite if the oxide layer gets scraped off.

 

As a sort of reverse example of the problems you can run into; when radiation hardening the Juno probe they built the shielding around the electronics out of titanium because the preferred lead, (probably a volume thing, Jupiter has a really rough radiation around it so you need serious shielding and titanium whilst less heavy for a given level of shielding is also way more voluminous), wouldn't handle the launch G's without deforming.

 

Your not wrong that lighter materials will be preferred, but remember rockets also have volume limits to their pay,loads and in many cases the cost is primarily per launch not per kg. there's going to be cases where the volume density or the carry capacity of the rocket vs the satellite mass makes going with steel desirable. basically your right that non-ferrous will be first choice for most things. But there's a ton of edge cases where other materials are good.

It had to do with ore deposits iirc.  For a long time they couldn’t turn the type of titanium dioxide in beach sand into titanium metal effectively, and much like how the US has most of the world’s helium, Russia had most of the mineral that folks could make titanium out of.  That changed I think before the Soviet Union fell. 

[CarlBar]

51 minutes ago, Bombastinator said:

It had to do with ore deposits iirc.  For a long time they couldn’t turn the type of titanium dioxide in beach sand into titanium metal effectively, and much like how the US has most of the world’s helium, Russia had most of the mineral that folks could make titanium out of.  That changed I think before the Soviet Union fell. 

 

That makes sense though i'd have to do some digging to see what exactly changed.

 

Quick TLDR on Titanium production.

 

Starts by chlorination of the ore, the aim is to produce titanium tetra-chloride. It need to be pure for the next step so you'll have to purify it to get out all the other junk that might have been chlorinated along with it, (this would make titanium from sand an issue as there'd be a lot of silica at the start, the chlorinates of which you have to filter off). The titanium tetra-chloride will decompose in the presence of water or oxygen as well producing titanium dioxide and hydrogen chloride gas, (hence it's use for a good while in smoke shells), so inert atmospheres and dry conditions are a necessity. 

 

After that it gets put through the kroll process where titanium tetra-chloride is heated and mixed with liquid magnesium metal, (Again inert atmosphere and dry environment required), this reduces most the the starting material to magnesium chloride and titanium metal, with some of the lesser titanium chlorides mixed in, (titanium mono/di/tri-chloride), so you have to do an additional step, (few methods), to seperate out the pure titanium metal (>99% pure), which you can then use for alloying for most purposes. Very high spec stuff, (like fan disks in aerospace jet engines), need higher purities and that involves additional steps.

 

I suspect the change was in the chlorination step as beach sand doubtless includes a mountain of troublesome impurities, handling that in a commercially viable way is non-trivial.

[Letgomyleghoe]

how about we clean up our own planet first before we worry about space.

[Bombastinator]

19 minutes ago, Letgomyleghoe said:

how about we clean up our own planet first before we worry about space.

The two may have to go hand in hand.  Space is really handy for doing measurements from.  I take your point though.  I fear that it may be too late, but I take your point.  Even if it fails raging against the dying of the light is worth doing.

[Jtalk4456]

3 hours ago, Zulu-Cheese-Alpha-IV said:

There is barely any junk out there, they seem to be misunderstanding the vastness of the incomprehensible.

While the vastness of space is indeed great, "barely" is not a word I'd use to describe the amount of space junk

[Bombastinator]

17 minutes ago, Jtalk4456 said:

While the vastness of space is indeed great, "barely" is not a word I'd use to describe the amount of space junk

Depends on how you think about it.  Deep in mind that scale wise each of those dots are about the size of England. 

[Jtalk4456]

3 minutes ago, Bombastinator said:

about the size of England. 

that makes it even scarier...

[Bombastinator]

9 hours ago, Jtalk4456 said:

that makes it even scarier...

Not if the pieces of junk are not actually the size of England.  It means the the thing is misleading. 

[Bombastinator]

1 hour ago, bearnard1212 said:

According to the information of the February 2020- over 2666 operational satellites and over 128 million pieces of debris flying around, the space junk issue has never been more pressing. The commercialisation of space is crowding Earth’s orbit at an unprecedented rate, with hundreds of spacecrafts being launched into space every year.

That future stuff has to be designed to be cleanupable at the very least goes without saying.  Perhaps that is all this thing is for.  There is not adding more and there is reducing what is there. 

[Jtalk4456]

12 hours ago, Bombastinator said:

Not if the pieces of junk are not actually the size of England.  It means the the thing is misleading. 

well if they're not the size of england why did you say that? doesn't make the graph misleading cuz you called them that big. But even being small, that's a lot of space junk. There's no Barely about that cloud of dots. If they keep going at current rate, they actually at some point may not be able to launch any more due to not having a safe orbit entry. That was specifically mentioned in the article

[Bombastinator]

1 hour ago, Jtalk4456 said:

well if they're not the size of england why did you say that? doesn't make the graph misleading cuz you called them that big. But even being small, that's a lot of space junk. There's no Barely about that cloud of dots. If they keep going at current rate, they actually at some point may not be able to launch any more due to not having a safe orbit entry. That was specifically mentioned in the article

Why did I say that?  Because that’s how big the dots are there. It’s not a graph.  Or not exactly anyway.  It’s a graphical representation of space junk.  Not a graph but a graphic. In order to make the pieces of space junk visible compared to a planet the size of a quarter that is the only way to show it.  The thing is those things vary wildly in size between something the size of a booster tank to something tha size of your fist.  The dots make them look way way bigger than they are though.  What makes them less dangerous is each piece of material has had its orbit precisely calculated.  If two of them collide though suddenly there are an unknown number of pieces and their orbits become suddenly unknown.  This creates a cone of probable location which is vastly larger than the actual size of the object.  To make it worse if a collision happens the probability exists for one of the now unknown objects to hit another doubling the problem.  Ithese a objects are also incredibly dangerous if you happen to be near one of them.  They can have astounding relative velocities.  To put something in orbit takes a lot of delta vee, and the farther out (or larger) something is the more it has.   This is one of the problems with the whole trash collection concept.  To move them out of the orbit they are in the vector has to be changed, and that takes however much fuel was used to put it there in the first place.  A lot of people think it’s like a space game and you can just go around picking things up.  You can’t.  Space in games isn’t realistic because real space would make an astoundingly shitty unforgiving game.  I was reading a thing about a game called “cruel world” which was actually designed to suck.  That game doesn’t suck nearly as hard as space.

[Jtalk4456]

12 hours ago, Bombastinator said:

1. The thing is those things vary wildly in size between something the size of a booster tank to something tha size of your fist.  The dots make them look way way bigger than they are though.

2. What makes them less dangerous is each piece of material has had its orbit precisely calculated.

3. If two of them collide though suddenly there are an unknown number of pieces and their orbits become suddenly unknown.  This creates a cone of probable location which is vastly larger than the actual size of the object.  To make it worse if a collision happens the probability exists for one of the now unknown objects to hit another doubling the problem.

4. To move them out of the orbit they are in the vector has to be changed, and that takes however much fuel was used to put it there in the first place.

1. Thing is I'm not looking at the size of the dots, but the sheer number of them, which is the issue.

Quote

 

The sheer number of objects in Earth's orbit may already be having a Kessler-like effect. Experts say that space congestion has gotten significantly worse since companies like SpaceX began launching large fleets of internet satellites into orbit.

"This has a massive impact on the launch side," Rocket Lab CEO Peter Beck told CNN Business in October. He added that rockets "have to try and weave their way up in between these [satellite] constellations."

 

(From the 1st article)

2. That means nothing when one dead piece of junk collides with something else.
 

Quote

 

In October, a defunct Soviet satellite and an old Chinese rocket body passed alarmingly close together. Since nobody could control either spacecraft, there was no way to prevent a collision.

Luckily, the objects did not crash. But if they had, astronomer Jonathan McDowell calculated it would have produced an explosion roughly equivalent to detonating 14 metric tons of TNT and sent chunks of spacecraft rocketing in all directions.

...

Scientists have observed real collisions in space as well. In 2007, China tested an anti-satellite missile by obliterating one of its own weather satellites. Two years later, one American and one Russian spacecraft accidentally collided. Those two events alone increased the amount of large debris in low-Earth orbit by about 70%.

...

Even tiny bits of space debris are dangerous, since they zip around the planet at roughly 10 times the speed of a bullet. Last year, the International Space Station had to maneuver away from space debris on three occasions, since a collision could endanger the astronauts on board.

3. Yeah exactly my point, regardless of how small the dots are, they exist and in that number, existing is an issue.

4. Care to explain how moving orbits takes the same amount of fuel as breaking thru the atmosphere and setting the orbit? That doesn't begin to make sense.

[Bombastinator]

My memory was the point originally made was there was that there was a lot of space for things to miss each other because the area involved is several times larger than the volume of the entire earth. You rebutted with the graphic but the graphic while honest about number doesn’t work for volume because the dots don’t show accurate volume.  It becomes a question of how important volume is.  I’m not sure the volume actually is as important a factor because while two objects may or may not miss each other if their oversized dots intersect the mere intersection means they possibly could have which could screw up predictions enormously.  The issue seems to be how well and fast can things be tracked.  If each of the objects could be accurately tracked in real time it would’nt necessarily be a problem but I doubt they can.  I don’t know how long it took to make that map but it could well have been years.  In such a case unknowns can multiply geometrically potentially much faster than they can be reduced again so accommodation has to be made.

Edited April 13, 2021 by Bombastinator

[StDragon]

From The Verge

 

Quote

The European Space Agency says the piece of debris that caused this particular chip was "possibly a paint flake or small metal fragment no bigger than a few thousandths of a millimeter across."

 

THE THREAT OF A PAINT FLAKE

 

It's pretty unnerving that something so small could cause such a significant crack, but the ISS is orbiting Earth at 17,150 miles per hour. The Cupola's massive 80 cm windows are made of fused silica and borosilicate glass that can help it withstand the force of this space junk — to an extent. An impact like the one above poses no real threat to the ISS, according to the ESA, but debris up to 1 cm could cause critical damage while anything larger than 10 cm could "shatter a satellite or spacecraft into pieces."

 

Paint flakes - let that sink in (no pun intended).

 

The only practical way of cleaning up space junk this small is with a laser. With enough energy, the ablation might be to knock it out of orbit and into space. Or, at least park within the vicinity of a Lagrange point.

 

I don't think anyone wants a laser pointed toward earth however unless the beam will strike the ocean. The concern being enough reflective scatter to cause blindness for anyone in the literal line-of-sight  (it's known to happen in industrial accidents involving high class lasers).

[CarlBar]

4 hours ago, Bombastinator said:

My memory was the point originally made was there was that there was a lot of space for things to miss each other because the area involved is several times larger than the volume of the entire earth. You rebutted with the graphic but the graphic while honest about number doesn’t work for volume because the dots don’t show accurate volume.  It becomes a question of how important volume is.  I’m not sure the volume actually is as important a factor because while two objects may or may not miss each other if their oversized dots intersect the mere intersection means they possibly could have which could screw up predictions enormously.  The issue seems to be how well and fast can things be tracked.  If each of the objects could be accurately tracked in real time it would’nt necessarily be a problem but I doubt they can.  I don’t know how long it took to make that map but it could well have been years.  In such a case unknowns can multiply geometrically potentially much faster than they can be reduced again so accommodation has to be made.

 

I went back and checked, someone was claiming because space is so vast there's little danger of collision.

 

Didn't get round to addressing this at the time, but thing sin orbits don't stay in place and if there's any eccentricity in the orbits of two objects that have their orbits cross each other then sooner or later they will run into each other. Because eccentricity means the two objects time to complete an orbit is not identical, and that means the amount of distance by which they miss at the crossing point is constantly changing, eventually it will hit zero.

 

You have to think of a satellites size as not it's physical size, but a bar forming a ring aroudn the earth with a thickness thats based on the largest possibble cross section of the satellite. Throw in uncertainties about the velocity and/or position and/or orbit of some objects and a single object can make a very large chunk of real estate unusable.

 

And on top of that a lot of the empty orbits out their aren't very useful for anything, and when where sending something outside of earth orbit, (or from a low orbit to a higher one) then where further constrained on the exit we can take, various factors say that staying within the plane of the orbit your aiming for is best, that creates a relatively narrow set of trajectories out of LEO or off the surface of the earth, if those get clogged with debris getting from low orbit to anywhere else becomes much more difficult.

 

If push came to shove we really could deal with a major mess up their that made launches difficult but it would be insanely expensive and difficult.

[Bombastinator]

1 hour ago, CarlBar said:

 

I went back and checked, someone was claiming because space is so vast there's little danger of collision.

 

Didn't get round to addressing this at the time, but thing sin orbits don't stay in place and if there's any eccentricity in the orbits of two objects that have their orbits cross each other then sooner or later they will run into each other. Because eccentricity means the two objects time to complete an orbit is not identical, and that means the amount of distance by which they miss at the crossing point is constantly changing, eventually it will hit zero.

 

You have to think of a satellites size as not it's physical size, but a bar forming a ring aroudn the earth with a thickness thats based on the largest possibble cross section of the satellite. Throw in uncertainties about the velocity and/or position and/or orbit of some objects and a single object can make a very large chunk of real estate unusable.

 

And on top of that a lot of the empty orbits out their aren't very useful for anything, and when where sending something outside of earth orbit, (or from a low orbit to a higher one) then where further constrained on the exit we can take, various factors say that staying within the plane of the orbit your aiming for is best, that creates a relatively narrow set of trajectories out of LEO or off the surface of the earth, if those get clogged with debris getting from low orbit to anywhere else becomes much more difficult.

 

If push came to shove we really could deal with a major mess up their that made launches difficult but it would be insanely expensive and difficult.

My memory is polar orbit stuff is eccentric so there is already stuff in there with known eccentric orbits.  There was some sort of scare about an approaching asteroid that turned out to be space junk.  Some ancient booster or something that had a wildly eccentric orbit.  The problem is eventually can be a mighty long time.  You may have solid reasoning.  My thought ran on a different path though it came to more or less the same conclusion.  Either, neither, or both may be the worry.  I don’t know.

 

There’s a thing called a parking orbit. I don’t know how they work though. My worry is about how locations of these things are determined.  There relatively tiny non light emitting things very very far away that move very fast.  A lot of those locations could have been derived from other stuff.   I don’t know how that is done but it may be done many different ways.  If not, it’s not a known location but a known area of location.  One that possibly gets bigger over time.  As such any change made to that object’s vector could mess EVERYTHING up, and those possible areas could get massively bigger very fast. 

Edited April 13, 2021 by Bombastinator

[CarlBar]

Eccentricity in this case refers to is how much the orbit differs from a perfect circle. Your thinking of inclination with the polar thing, though orbits away from the equator are harder to egt low eccentricity on.

 

As for where a lot of this stuff is, provided you have acurratte data from the launch on velocity and vector anything discarded can be plotted out fairly accurately, plus most of the things bigger than a man are going to show up on space tracking radar. The catches as far as disaster potential are:

 

 

A) We only generally predict orbits out to a very limited time in front, from a you or i perspective it's a long time, (years at the minimum, generally decades or more), but there comes a point at which the complex gravity interactions, (we can only account for so many gravity sources in our current modelling), make it effectively impossible. So somthing could cause an issue a hundred years from now, but we might not be able to see it in our simulations.

 

B) Things go wrong, bits fall off at times and places stuff isn't supposed to fall off. This can even happen well after a satellite is in orbit. This results in 2 or more objects travelling in orbits neither of which matches the pre-mishap orbit. Suddenly things that where safe no longer are.

 

C) The effect of the earths atmosphere on lower orbiting objects can be unpredictable as the atmosphere expands and contracts based on many factors, some of which we can't predict. In a similar vein varying solar activity changes the radiation pressure effecting things in orbit. That throws things some more, (refer back to point A for the consequences).

 

D) You can never rule out deliberate action by nation states at some point.

 

TLDR we know pretty well where everything is, but there's enough things we can't model and enough edge cases to create some real trouble potential over time.

[Bombastinator]

35 minutes ago, CarlBar said:

Eccentricity in this case refers to is how much the orbit differs from a perfect circle. Your thinking of inclination with the polar thing, though orbits away from the equator are harder to egt low eccentricity on.

 

As for where a lot of this stuff is, provided you have acurratte data from the launch on velocity and vector anything discarded can be plotted out fairly accurately, plus most of the things bigger than a man are going to show up on space tracking radar. The catches as far as disaster potential are:

 

 

A) We only generally predict orbits out to a very limited time in front, from a you or i perspective it's a long time, (years at the minimum, generally decades or more), but there comes a point at which the complex gravity interactions, (we can only account for so many gravity sources in our current modelling), make it effectively impossible. So somthing could cause an issue a hundred years from now, but we might not be able to see it in our simulations.

 

B) Things go wrong, bits fall off at times and places stuff isn't supposed to fall off. This can even happen well after a satellite is in orbit. This results in 2 or more objects travelling in orbits neither of which matches the pre-mishap orbit. Suddenly things that where safe no longer are.

 

C) The effect of the earths atmosphere on lower orbiting objects can be unpredictable as the atmosphere expands and contracts based on many factors, some of which we can't predict. In a similar vein varying solar activity changes the radiation pressure effecting things in orbit. That throws things some more, (refer back to point A for the consequences).

 

D) You can never rule out deliberate action by nation states at some point.

 

TLDR we know pretty well where everything is, but there's enough things we can't model and enough edge cases to create some real trouble potential over time.

That is the definition I was using.  I forget why they do eccentric polar orbits.  There was a reason though. Maybe something Cold War oriented.  It was a big reason the space shuttle needed solid rocket boosters.  The military needed tha ability so it made things heavier.  The original shuttle designs didn’t have solid rocket boosters it was just the plane and the big tank.

 

re:C

My understanding is anything that comes close enough to the earth to have issues with atmosphere is going to reenter pretty quickly so probably doesn’t matter much.  The thing is  I also understand things at the wrong angle can actually bounce off the atmosphere.  Not sure what that is or how it works. 

Edited April 14, 2021 by Bombastinator