Author Topic: Missile Defense Tech vs. Asteroid Debris Threat  (Read 4152 times)

Offline DarkenedOne

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Missile Defense Tech vs. Asteroid Debris Threat
« on: 03/22/2011 10:42 PM »
For a long time I have been wondering whether or not missile defense technology and techniques could be used in spaceflight to defend the ISS and perhaps satellites from the micrometeriod and debris threat.

Of course it is a challenge.  Such pieces of debris could come in at 20 km/s.

Personally I think it would be possible for small threat to be taken out with a fast acting laser. 

Larger threats could be detected at a greater distance, so giving a gun or missile system time to react.

Just a few ideas, although I do not know how practical they are from a technical and political perspective. 

Such active defense would likely be considered by some to be ASAT.  Of course their short range would make them useful for such a purpose only at very short range. 


Offline LegendCJS

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #1 on: 03/22/2011 10:52 PM »
For a long time I have been wondering whether or not missile defense technology and techniques could be used in spaceflight to defend the ISS and perhaps satellites from the micrometeriod and debris threat.

Of course it is a challenge.  Such pieces of debris could come in at 20 km/s.

Personally I think it would be possible for small threat to be taken out with a fast acting laser. 

Larger threats could be detected at a greater distance, so giving a gun or missile system time to react.

Just a few ideas, although I do not know how practical they are from a technical and political perspective. 

Such active defense would likely be considered by some to be ASAT.  Of course their short range would make them useful for such a purpose only at very short range. 



Doing any of this against orbital debris in space will only make the debris population increase.  You have to find a way to de-orbit this stuff.
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline DarkenedOne

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #2 on: 03/23/2011 12:37 PM »
For a long time I have been wondering whether or not missile defense technology and techniques could be used in spaceflight to defend the ISS and perhaps satellites from the micrometeriod and debris threat.

Of course it is a challenge.  Such pieces of debris could come in at 20 km/s.

Personally I think it would be possible for small threat to be taken out with a fast acting laser. 

Larger threats could be detected at a greater distance, so giving a gun or missile system time to react.

Just a few ideas, although I do not know how practical they are from a technical and political perspective. 

Such active defense would likely be considered by some to be ASAT.  Of course their short range would make them useful for such a purpose only at very short range. 



Doing any of this against orbital debris in space will only make the debris population increase.  You have to find a way to de-orbit this stuff.

Not necessarily.  Lasers could be used as I said to vaporize smaller pieces.

Offline LegendCJS

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #3 on: 03/23/2011 07:02 PM »
For a long time I have been wondering whether or not missile defense technology and techniques could be used in spaceflight to defend the ISS and perhaps satellites from the micrometeriod and debris threat.

Of course it is a challenge.  Such pieces of debris could come in at 20 km/s.

Personally I think it would be possible for small threat to be taken out with a fast acting laser. 

Larger threats could be detected at a greater distance, so giving a gun or missile system time to react.

Just a few ideas, although I do not know how practical they are from a technical and political perspective. 

Such active defense would likely be considered by some to be ASAT.  Of course their short range would make them useful for such a purpose only at very short range. 



Doing any of this against orbital debris in space will only make the debris population increase.  You have to find a way to de-orbit this stuff.

Not necessarily.  Lasers could be used as I said to vaporize smaller pieces.

Lasers may be able to vaporize very small specks of stuff that is painted black or otherwise absorbing to the wavelength used, but stuff of the size that can be completely turned to gas by any laser you would bother putting in space can't be tracked by radar with sufficient accuracy to target it.  And for the same sized objects you could just let the micrometeorite and debris shields that will always be present on the ISS or future stations handle that small stuff.  The shielding will have to be there regardless as a backup, because radar can't spot this small stuff at all or in time (depending on the size and speed).

If the debris is shiny or reflective to the wavelength used, the laser won't be able to do squat.  If the item is large enough to be tracked by radar for long enough to target a laser on it, the laser won't be able to turn it all into gas.  It would just sputter off layers of material where it strikes making more paint fleck type debris.

If you could target the debris repeatedly on many passes in a controlled way to make the sputtering material impart a thrust to the debris such that the object was de-orbited you might have something.  But then you have to make the trade-off between the cost of re-positioning fuel for the ISS vs the cost of the laser and supplying its firing fuel (the "star-wars" rejected all laser types except chemical lasers- probably on the basis of their being compact and maneuverable; no need for acres of solar panels).  And each 'hit' will nudge the debris so lightly that you can't rely on this kind of system to protect your space station from a suddenly detected threat - so you still have to move the station out of the way.

Now you get into the realm of the studies that have already been conducted on ground lasers being used to remove orbital debris.  Here is one reference: http://www.au.af.mil/au/awc/awcgate/cst/csat20.pdf
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline DarkenedOne

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #4 on: 03/26/2011 05:08 PM »
For a long time I have been wondering whether or not missile defense technology and techniques could be used in spaceflight to defend the ISS and perhaps satellites from the micrometeriod and debris threat.

Of course it is a challenge.  Such pieces of debris could come in at 20 km/s.

Personally I think it would be possible for small threat to be taken out with a fast acting laser. 

Larger threats could be detected at a greater distance, so giving a gun or missile system time to react.

Just a few ideas, although I do not know how practical they are from a technical and political perspective. 

Such active defense would likely be considered by some to be ASAT.  Of course their short range would make them useful for such a purpose only at very short range. 



Doing any of this against orbital debris in space will only make the debris population increase.  You have to find a way to de-orbit this stuff.

Not necessarily.  Lasers could be used as I said to vaporize smaller pieces.

Lasers may be able to vaporize very small specks of stuff that is painted black or otherwise absorbing to the wavelength used, but stuff of the size that can be completely turned to gas by any laser you would bother putting in space can't be tracked by radar with sufficient accuracy to target it.  And for the same sized objects you could just let the micrometeorite and debris shields that will always be present on the ISS or future stations handle that small stuff.  The shielding will have to be there regardless as a backup, because radar can't spot this small stuff at all or in time (depending on the size and speed).

If the debris is shiny or reflective to the wavelength used, the laser won't be able to do squat.  If the item is large enough to be tracked by radar for long enough to target a laser on it, the laser won't be able to turn it all into gas.  It would just sputter off layers of material where it strikes making more paint fleck type debris.

If you could target the debris repeatedly on many passes in a controlled way to make the sputtering material impart a thrust to the debris such that the object was de-orbited you might have something.  But then you have to make the trade-off between the cost of re-positioning fuel for the ISS vs the cost of the laser and supplying its firing fuel (the "star-wars" rejected all laser types except chemical lasers- probably on the basis of their being compact and maneuverable; no need for acres of solar panels).  And each 'hit' will nudge the debris so lightly that you can't rely on this kind of system to protect your space station from a suddenly detected threat - so you still have to move the station out of the way.

Now you get into the realm of the studies that have already been conducted on ground lasers being used to remove orbital debris.  Here is one reference: http://www.au.af.mil/au/awc/awcgate/cst/csat20.pdf

1. It probably would not be a good idea to use radar to track space debris anyway.  These things would probably be better tracked in space by either LIDAR or simply detecting the light from the sun that is reflected off them with far greater resolution.

2.  Lasers can be used to vaporize objects, but also to move them.  Its called laser propulsion.

3.  Space lasers for this purpose would not be chemically powered.  While chemical lasers have good power for their size they would extremely expensive to operate in space.  Electrically powered lasers would be more appropriate for this applications as they would be powered by solar.

4.  The strategy to deal with debris depends on the orbit it is in.  If the debris is in the ISS orbit where atmospheric resistance is still significant, then a good strategy is to simply break up the debris into smaller pieces.  Breaking the debris up will increase its drag to mass ratio, thus causing it to deorbit faster. 
   

Online hop

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #5 on: 03/26/2011 09:21 PM »
1. It probably would not be a good idea to use radar to track space debris anyway.
That would come as news to the people who use radar for this purpose every day.

Offline DarkenedOne

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #6 on: 03/28/2011 01:51 AM »
1. It probably would not be a good idea to use radar to track space debris anyway.
That would come as news to the people who use radar for this purpose every day.


Radar is an active detection system that bounces  radar waves off a target in order to detect it.

Radio waves are very good for detection on Earth because unlike light they do not suffer from as many atmospheric effects as regular light.  In addition many of the objects we use radar to detect are made of metal thus reflect it fairly well.

For a space based detection system I do not believe that radar would be a good choice for debris tracking because the debris could very well be smaller than the wavelength of the radar you are using and it could be made of something the is not very metallic. 

Since you have the sun providing a decent illumination anyway, and you do not have to worry about atmospheric effects it makes more sense to passive system that is able to detect in multiple wavelengths.  This way you do not have to worry as much about small pieces of debris that are difficult for radar to detect.

Got to remember its all the EM spectrum.  Which part of the spectrum one chooses to use should depend on the medium through which they plan to use it, and what they intend to detect. 

Offline missinglink

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Re: Missile Defense Tech vs. Asteroid Debris Threat
« Reply #7 on: 04/04/2011 12:35 PM »
Somewhat off-topic, where can I find information on the ISS micrometeorite/debris shielding?

In my mind's eye, I envision a sphere around the ISS where micrometeorites can come at it from all angles. But one hemisphere is closed off by nearby Earth, the best shield one could ask for ;)

So how much of the remaining hemisphere is covered by the ISS shields? Is there a graphic someplace?

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