MORE AND MORE SPACE DEBRIS COLLISIONS OCCURING.

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Was not losing your greasegun in space covered in the course? <br /> Posted by earth_bound_misfit</DIV></p><p>Sure. They could calculate the orbit / re-entry parametres based on the estimation of how fast the tools grew distance to ISS and also the direction the items moved away from ISS's yaw axis.&nbsp;</p><p>By the way, moving from one orbit to another is called translation control in space cadet's hand-book.&nbsp;</p>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Sure. There is no way to just leave something behind on orbit. If I held a tennis ball in my hand outside the ISS and released the ball, it would continue on the same path as I did. To leave the tennis ball behind I would need to throw it to the opposite direction that I was travelling.This would give an equal boost to both the tennis ball and the ISS. Naturally the ball would feel the effect much more strongly because of the difference in the masses of both objects. I have just taken several courses on mechanics and orbital mechanics in the Uni, so that's why I like to speak about it. &nbsp; <br />Posted by aphh</DIV><br /><br />I guess that's the difference in our interpretations. To me, "leaving behind" is exactly what you described. Leaving a tennis ball behind, i.e. letting go from your hand while in orbit with no velocity change. Due to it's lower mass/surface area ratio, it will slowly fall behind and deorbit.</p><p>To me, throwing the ball in the minus vector direction is deceleration. I would call that "throwing behind" rather than "leaving behind".</p><p>I suspect our terminologies are creating the confusion.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I guess that's the difference in our interpretations. To me, "leaving behind" is exactly what you described. Leaving a tennis ball behind, i.e. letting go from your hand while in orbit with no velocity change. Due to it's lower mass/surface area ratio, it will slowly fall behind and deorbit.To me, throwing the ball in the minus vector direction is deceleration. I would call that "throwing behind" rather than "leaving behind".I suspect our terminologies are creating the confusion. <br /> Posted by MeteorWayne</DIV></p><p>What would make the ball lose velocity if simply released from hand with no velocity change? Sure it has less kinetic energy, but to slow down an object on orbit means a change in velocity. There has to be a cause for that change.<br /><br />I think it is athmospheric drag that is constantly slowing down the ISS, but the ball would have far less surface area&nbsp; perpendicular to it's motion vector thus creating less drag? <br /><br />In that sense the ISS would slow down first, not the ball. Perhaps it's the surface to mass ratio, that decides which object slows down first. The air molecules would resist a lighter object, like a tennis ball, more compared to a ball that was made of, say, gold but had a similar size and surface area than the tennis ball.</p><p>So the object that has less kinetic energy compared to it's athmospheric drag coefficient will slow down faster.&nbsp;</p>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What would make the ball lose velocity if simply released from hand with no velocity change? Sure it has less kinetic energy, but to slow down an object on orbit means a change in velocity. There has to be a cause for that change.I think it is athmospheric drag that is constantly slowing down the ISS, but the ball would have far less surface area&nbsp; perpendicular to it's motion vector thus creating less drag? In that sense the ISS would slow down first, not the ball. Perhaps it's the surface to mass ratio, that decides which object slows down first. The air molecules would resist a lighter object, like a tennis ball, more compared to a ball that was made of, say, gold but had a similar size and surface area than the tennis ball.So the object that has less kinetic energy compared to it's athmospheric drag coefficient will slow down faster.&nbsp; <br />Posted by aphh</DIV><br /><br />It's the other way around. The ball has far more surface relative to it's mass, so the tenuous atmospher would slow it down much faster. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It's the other way around. The ball has far more surface relative to it's mass, so the tenuous atmospher would slow it down much faster. <br /> Posted by MeteorWayne</DIV></p><p>That's what I said also at the end after evaluation of the scenario.</p><p>If there were 2 objects on the same orbit with equal dimensions and shape, but the other object was only half the mass of the other, the forces acting on the objects to slow them down would be felt more strongly on the object with less mass thus slowing down more rapidly.</p><p>Kinetic energy is 1/2m * v^2, where m is the mass of the object and v is the velocity. The object with more mass has stored more kinetic energy and is thus harder to stop by outside forces acting on it, presuming that the 2 objects were of similar size and shape.&nbsp;</p>

 

[cyclonebuster]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That's what I said also at the end after evaluation of the scenario.If there were 2 objects on the same orbit with equal dimensions and shape, but the other object was only half the mass of the other, the forces acting on the objects to slow them down would be felt more strongly on the object with less mass thus slowing down more rapidly.Kinetic energy is 1/2m * v^2, where m is the mass of the object and v is the velocity. The object with more mass has stored more kinetic energy and is thus harder to stop by outside forces acting on it, presuming that the 2 objects were of similar size and shape.&nbsp; <br />Posted by aphh</DIV><br /><br />The Kinetic Energy would also boost the debris to a higher orbit after the collision.

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The Kinetic Energy would also boost the debris to a higher orbit after the collision. <br />Posted by cyclonebuster</DIV><br /><br />Maybe, maybe not. that depends on the exact kinematics of the collision. If they hit head on, both would slow down. If one hit the other from behind, the one in front would speed up.</p><p>At angles in between, it's not a simple proposition where you can state with any certainty what will happen.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[aphh]

<p>Yes, in a scenario where one object was bumped in the rear by another object, one would gain energy sending it to potentially higher orbit, whereas the other would lose energy sending it potentially hurtling towards us.</p><p>Any fragmentation could be sent to any direction. </p><p>The skies are polluted by debris, and it is entirely the fault of the humans. We need to clean up what we polluted.&nbsp;</p>

 

[job1207]

<p>Firstly, the FAA was the one doing the warning, NOT the Russians or the Brazilian bikini squad but the FAA. So I would take that to heart. </p><p>&nbsp;</p><p>Secondly, all Cosmos vehicles were nuclear. They were sent to parking orbits until the toxicity of their nuclear fuel abated. Premature reentry presents interesting questions, at the least. </p><p>&nbsp;</p><p>Thirdly, everyday, near misses occur.&nbsp; </p><p>http://celestrak.com/cgi-bin/searchSOCRATES.pl</p><p>&nbsp;</p><p>Fourtly. I hope that someone invents something that can deal with space debris in the next decade. This problem is only going to get worse.&nbsp; </p>

 

[cyclonebuster]

<p>&nbsp;</p><p>"Fourtly. I hope that someone invents something that can deal with space debris in the next decade. This problem is only going to get worse.&nbsp;"</p><p>We can use a solar powered orbital laser station to either vaporise objects or de-orbit them and let them burn up in the atmosphere.</p>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Firstly, the FAA was the one doing the warning, NOT the Russians or the Brazilian bikini squad but the FAA. So I would take that to heart. &nbsp;Secondly, all Cosmos vehicles were nuclear. They were sent to parking orbits until the toxicity of their nuclear fuel abated. Premature reentry presents interesting questions, at the least. &nbsp;Thirdly, everyday, near misses occur.&nbsp; http://celestrak.com/cgi-bin/searchSOCRATES.plFourtly. I hope that someone invents something that can deal with space debris in the next decade. This problem is only going to get worse.&nbsp; <br />Posted by job1207</DIV><br /><br />Not sure who you were replying to, but the FAA was wrong, as they admitted the next day. Heart doesn't equal brains, sometimes. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[job1207]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not sure who you were replying to, but the FAA was wrong, as they admitted the next day. Heart doesn't equal brains, sometimes. <br /> Posted by MeteorWayne</DIV></p><p>I see, the FAA admitted to being wrong. I did not see the next day report. Thanks.&nbsp; </p>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I see, the FAA admitted to being wrong. I did not see the next day report. Thanks.&nbsp; <br />Posted by job1207</DIV><br /><br />I'm not sure in the National Weather Service ever admitted their mistake... <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[job1207]

The sky is falling, the sky is falling. er rather, it WILL rain on Tuesday, really.

 

[samkent]

<p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2">Since we cannot track small objects (marble sized and smaller), I don&rsquo;t think the laser is a practical idea. If you have ground control decide which objects get blasted, the firing rate would be very slow. If you have the satellite target and fire, you run the risk of hitting things you shouldn&rsquo;t. Plus you still don&rsquo;t blast the small ones.</font></p><font size="2"><font face="Times New Roman">&nbsp;</font><span style="font-size:12pt;font-family:'TimesNewRoman'">The giant foam blob requires no targeting from the ground. It gathers the small things and redirects the larger ones. It will be easily tracked from the ground and could last for many years. The only down side is you may have to move active satellites to avoid collisions.</span></font>

 

[cyclonebuster]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Since we cannot track small objects (marble sized and smaller), I don&rsquo;t think the laser is a practical idea. If you have ground control decide which objects get blasted, the firing rate would be very slow. If you have the satellite target and fire, you run the risk of hitting things you shouldn&rsquo;t. Plus you still don&rsquo;t blast the small ones.&nbsp;The giant foam blob requires no targeting from the ground. It gathers the small things and redirects the larger ones. It will be easily tracked from the ground and could last for many years. The only down side is you may have to move active satellites to avoid collisions. <br />Posted by samkent</DIV></p><p>&nbsp;</p><p>Perhaps we can use what the Boeing Airborne Laser uses except in space to de-orbit the debris.</p>

 

[tanstaafl76]

<p>Maybe we need to have an international moratorium on non-maneuverable space objects with an orbital lifetime of greater than 5 years so that at least we stop adding to the mess and give us time to work on a solution. &nbsp;It won't do anyone any good to make orbital space a giant game of deadly dodgeball.</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[cyclonebuster]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe we need to have an international moratorium on non-maneuverable space objects with an orbital lifetime of greater than 5 years so that at least we stop adding to the mess and give us time to work on a solution. &nbsp;It won't do anyone any good to make orbital space a giant game of deadly dodgeball.&nbsp; <br />Posted by tanstaafl76</DIV></p><p>Good point! However even in dodgeball you can still get hit.</p>

 

[nimbus]

I reckon having the ability to clean up is what's most valuable. Repairing collision damage and preventing debris won't be perfected for a while yet, and we're already seeing vital missions like the Hubble repair mission being scrubbed because of what debris we already have today. <div class="Discussion_UserSignature"> </div>

 

[silylene]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe we need to have an international moratorium on non-maneuverable space objects with an orbital lifetime of greater than 5 years so that at least we stop adding to the mess and give us time to work on a solution. &nbsp;It won't do anyone any good to make orbital space a giant game of deadly dodgeball.&nbsp; <br />Posted by tanstaafl76</DIV></p><p>You should know that the Iridium was movable.&nbsp; The issue was that no one decided to move it.</p> <div class="Discussion_UserSignature"> <p align="center"><font size="1">petet = <font color="#800000"><strong>silylene</strong></font></font></p><p align="center"><font size="1">Please, please give me my handle back !</font></p> </div>

 

[scottb50]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You should know that the Iridium was movable.&nbsp; The issue was that no one decided to move it. <br /> Posted by petet</DIV></p><p>It is more likely that the odds of a collision were not close enough to require a change. If told a collision was imminent and it was ignored is one thing, if told a collision was possible, but the odds were pretty good against it is another thing. It seems to me they can track objects millions of miles away and define their position within a very small margin, that would lead me to believe the effort is not being made to precisely track orbital objects and identify possible problems. It's one thing to catalogue objects and another to predict conflicts.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[silylene]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It is more likely that the odds of a collision were not close enough to require a change. If told a collision was imminent and it was ignored is one thing, if told a collision was possible, but the odds were pretty good against it is another thing. It seems to me they can track objects millions of miles away and define their position within a very small margin, that would lead me to believe the effort is not being made to precisely track orbital objects and identify possible problems. It's one thing to catalogue objects and another to predict conflicts.&nbsp; <br />Posted by scottb50</DIV><br /><br />Actually, they had a 'conjunction report' on a possible issue.&nbsp; It was not acted upon.</p><p>The more complete story is that they got about 5 'conjunction reports'/week concerning Iridium satellites.&nbsp; The 'conjunction report' above was not even the most critical 'conjunction report' for an Iridium that week.&nbsp; Not once had any of these 'conjunction reports' been acted upon, and no Iridium had ever been moved as a result of a 'conjunction report'.&nbsp; The reports&nbsp;all went to the trash bin.</p><p>Had they moved an Iridium every time they received a 'conjunction report', truth is that the Iridiums would exhaust their fuel earlier than their expected lifetime.&nbsp; It was believed that the chance of collision was so low, that even with a 'conjunction report', the error bar of the report was big enough that they could be ignored.&nbsp; It was further believed that moving the satellites over slightly would not move them significantly outside of the collision error bar.&nbsp; I don't know if this belief was correct, I'd like to see a full statistical error analysis by a mathematician.&nbsp; Regardless, we now know after the fact that the 'conjunction reports' perhaps should not have been ignored.</p><p>As far as I know, ongoing new 'conjunction reports' concerning Iridiums&nbsp;continue to be ignored.</p><p>My guess now is that the other 60+ Iridiums are all at high risk of encountering the debris from the prior collision, since they share the same original orbital height.&nbsp; The next Iridium collision will generate even more debris.&nbsp; And the collision after this, even more debris.&nbsp; The chain reaction has just begun.&nbsp; It will probably take about 5-20 years to completely play out.&nbsp; It will be&nbsp; mess.&nbsp; An impossible to clean mess.</p><p>And at this point, I don't really know if moving an Iridium next time a 'conjunction report' is issued would even matter.&nbsp; I would just use the Iridium engines to de-orbit all of them, it is the only way to fix the problem.&nbsp; The Iridiums&nbsp;are next to useless anyways.&nbsp; Their technology has been surpassed by ground networks, and the company went bankrupt and its new owner has very few clients.</p> <div class="Discussion_UserSignature"> <p align="center"><font size="1">petet = <font color="#800000"><strong>silylene</strong></font></font></p><p align="center"><font size="1">Please, please give me my handle back !</font></p> </div>

 

[scottb50]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Actually, they had a 'conjunction report' on a possible issue.&nbsp; It was not acted upon.The more complete story is that they got about 5 'conjunction reports'/week concerning Iridium satellites.&nbsp; The 'conjunction report' above was not even the most critical 'conjunction report' for an Iridium that week.&nbsp; Not once had any of these 'conjunction reports' been acted upon, and no Iridium had ever been moved as a result of a 'conjunction report'.&nbsp; The reports&nbsp;all went to the trash bin.Had they moved an Iridium every time they received a 'conjunction report', truth is that the Iridiums would exhaust their fuel earlier than their expected lifetime.&nbsp; It was believed that the chance of collision was so low, that even with a 'conjunction report', the error bar of the report was big enough that they could be ignored.&nbsp; It was further believed that moving the satellites over slightly would not move them significantly outside of the collision error bar.&nbsp; I don't know if this belief was correct, I'd like to see a full statistical error analysis by a mathematician.&nbsp; Regardless, we now know after the fact that the 'conjunction reports' perhaps should not have been ignored.As far as I know, ongoing new 'conjunction reports' concerning Iridiums&nbsp;continue to be ignored.My guess now is that the other 60+ Iridiums are all at high risk of encountering the debris from the prior collision, since they share the same original orbital height.&nbsp; The next Iridium collision will generate even more debris.&nbsp; And the collision after this, even more debris.&nbsp; The chain reaction has just begun.&nbsp; It will probably take about 5-20 years to completely play out.&nbsp; It will be&nbsp; mess.&nbsp; An impossible to clean mess.And at this point, I don't really know if moving an Iridium next time a 'conjunction report' is issued would even matter.&nbsp; I would just use the Iridium engines to de-orbit all of them, it is the only way to fix the problem.&nbsp; The Iridiums&nbsp;are next to useless anyways.&nbsp; Their technology has been surpassed by ground networks, and the company went bankrupt and its new owner has very few clients. <br /> Posted by petet</DIV></p><p>Not that I don't agree with your premise that Iridium is superfolous there are a lot of weather, environmental and scientific satellites that the issue is still relevent. Since both had been in orbit for a long time it seems the orbits could be better defined to predict a collision as certain rather then a low enough probability to ignore it. The bigger problem is the collision spreads the debris to various orbits, higher, lower and in different inclinations. Now just getting to Hubble may be a problem, the ISS, because of it's inclination might be better off, but even though the time frame gets pretty wide, what goes up has to come down, unless it reaches escape velocity. </p> <div class="Discussion_UserSignature"> </div>

 

[SlyCoopersButt]

<p>Quite often lasers are a popular prosal, Yet they would make matters worse.&nbsp;Evaporating debris with lasers&nbsp;into a less harmful gaseous state which solar wind could dissperse out of orbit&nbsp;over time is scritcly Sci-Fi with our current technology. It would require monsterous amounts of energy we could never hope to get into a laser&nbsp;in our current&nbsp;time. I believe we are a long way off from that.</p><p>Using them to de-orbit objects&nbsp;over time would also be improbable as a solution as there are simply way too many objects for a few laser satellites whose technology would cost untold amounts. Not to mention the political implications they would pose being considered potential space weapons. What we have today in lasers would make as much of a mess as a kinetic kill warhead impact.</p><p>The only sensible solution I believe we have is to&nbsp;find alternatives in the world of communication to the use&nbsp;of&nbsp;satellites that are orbiting above&nbsp;low Earth orbit. We will have the technology to do so. Such as atmospheric satellites which are much cheaper that are on the edge of space. They look very promising for the future.</p> <div class="Discussion_UserSignature"> </div>

 

[cyclonebuster]

<p>I think a solar powered&nbsp;particle beam similar to the&nbsp;Boeing Airborne Laser would work quite nice.LOL!</p>