Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Hmmm. Looks like we are in for an even better firework display now then! Surley fragmenting something this big, will mean it is actually more likely for [something] to survive? - since you will create random pieces of debris with very differing velocities and therefore some might have more chance of having suitable rentry parameters which will allow them to survive... Either way - Really, this is not very good news for the low earth space environment! About time we had some proper global treaties in place to stop countries randomly polluting space, all for the sake of some commercial secrets (which are already probably common knowledge anyway). Best, Mark Ford CONFIDENTIALITY NOTICE: This email and any files transmitted with it are confidential. If you are not the intended recipient, please notify us. Email [EMAIL PROTECTED] You should not copy or use this email or attachment(s) for any purpose nor disclose their contents to any other person. GENERAL STATEMENT: Southern Scientific Ltd's computer systems may be monitored and communications carried on them recorded, to secure the effective operation of the system and for other lawful purposes. Registered address Rectory Farm Rd, Sompting, Lancing, W Sussex BN15 0DP. Company No 1800317 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Surley fragmenting something this big, will mean it is actually more likely for [something] to survive? I don't think so. Space debris reaches the ground when it is protected by large structures around it. Break it up into small pieces, and it's doubtful anything will survive. (While the official claim is that this is being done to protect people from falling, toxic debris, I think we all know better. It's being done so sensitive material doesn't end up dropping someplace we have no control over.) ...since you will create random pieces of debris with very differing velocities and therefore some might have more chance of having suitable rentry parameters which will allow them to survive... Probably not all that much variation in velocities. Either way - Really, this is not very good news for the low earth space environment! This is the _really_ low earth environment- only marginally space at all. While I suppose it's possible that a very few pieces could end up in higher orbits, on the whole there's nowhere near enough energy being delivered to have much effect on the average orbit. Breaking this satellite up into small pieces is just going to increase individual decay rates. Within a matter of days, the vast majority (if not all) of the junk is going to be gone. What the Chinese did last year was irresponsible, but destroying this satellite isn't going to produce any debris that we have to worry about. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Mark Ford [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com Sent: Friday, February 15, 2008 2:00 AM Subject: Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite Hmmm. Looks like we are in for an even better firework display now then! Surley fragmenting something this big, will mean it is actually more likely for [something] to survive? - since you will create random pieces of debris with very differing velocities and therefore some might have more chance of having suitable rentry parameters which will allow them to survive... Either way - Really, this is not very good news for the low earth space environment! About time we had some proper global treaties in place to stop countries randomly polluting space, all for the sake of some commercial secrets (which are already probably common knowledge anyway). Best, Mark Ford __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
On Fri, 15 Feb 2008 09:00:34 -, you wrote: About time we had some proper global treaties in place to stop countries randomly polluting space, all for the sake of some commercial secrets (which are already probably common knowledge anyway). The enemy probably already have the secret technology that the military is trying to protect anyway. http://www.cnsnews.com/news/viewstory.asp?Page=/ForeignBureaus/archive/200802/INT20080212b.html Surely this kind of thing is a lot more common than reaches public notice. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Hi, While I agree the likelihood of meaningful debris is very small, this NYTimes piece: http://www.nytimes.com/2008/02/15/us/15satellite.html?emex=1203224400en=2350567d2300e89bei=5087%0A contains a prediction that a successful hit on USA-193 will produce 100,000 pieces of new debris. I think that is a complicated engineering question that was almost certainly NOT evaluated by the person quoted, but I suppose it is a possibility. Rob pointed out that only a very small percentage of the debris will be directed into potentially dangerous orbits, but a small percentage of 100,000 is still a respectable number. The NYTimes piece contains further details of interest. The three-ship flotilla tasked with the takedown will operate in the North Pacific where, depending on the orbital inclination, a stripe running down orbit could stretch around the planet for a full orbit, down the Pacific, then across Antarctica, up the Atlantic, over the Arctic, or as close to this ideal as can be managed. I hope there's some attempt to derive as much data as possible from this little adventure. The SM-3's return a lot of data. There should be tracking ships down the line, I would think, to determine the progress of the breakup and to check for big chunks. Since the Times article implies that there will be only the one cruiser, it is unlikely that there will be more than the one attempt. Sterling K. Webb - Original Message - From: Chris Peterson [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com Sent: Friday, February 15, 2008 11:39 AM Subject: Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite Surley fragmenting something this big, will mean it is actually more likely for [something] to survive? I don't think so. Space debris reaches the ground when it is protected by large structures around it. Break it up into small pieces, and it's doubtful anything will survive. (While the official claim is that this is being done to protect people from falling, toxic debris, I think we all know better. It's being done so sensitive material doesn't end up dropping someplace we have no control over.) ...since you will create random pieces of debris with very differing velocities and therefore some might have more chance of having suitable rentry parameters which will allow them to survive... Probably not all that much variation in velocities. Either way - Really, this is not very good news for the low earth space environment! This is the _really_ low earth environment- only marginally space at all. While I suppose it's possible that a very few pieces could end up in higher orbits, on the whole there's nowhere near enough energy being delivered to have much effect on the average orbit. Breaking this satellite up into small pieces is just going to increase individual decay rates. Within a matter of days, the vast majority (if not all) of the junk is going to be gone. What the Chinese did last year was irresponsible, but destroying this satellite isn't going to produce any debris that we have to worry about. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Mark Ford [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com Sent: Friday, February 15, 2008 2:00 AM Subject: Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite Hmmm. Looks like we are in for an even better firework display now then! Surley fragmenting something this big, will mean it is actually more likely for [something] to survive? - since you will create random pieces of debris with very differing velocities and therefore some might have more chance of having suitable rentry parameters which will allow them to survive... Either way - Really, this is not very good news for the low earth space environment! About time we had some proper global treaties in place to stop countries randomly polluting space, all for the sake of some commercial secrets (which are already probably common knowledge anyway). Best, Mark Ford __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Hi, The large and unidentified experimental next-generation spy satellite, USA-193, that failed shortly after launch in December, 2006 and was expected to make an uncontrolled and destructive re-entry into the Earth's atmosphere at the end of February, will be shot down while still in orbit, the AP announced about 20 minutes ago. A press conference at the Pentagon to confirm this is expected sometime this afternoon, they say. http://ap.google.com/article/ALeqM5h7aoM2ii3QVBCAV8m2HtJSuPxPNwD8UQ7CEO0 Sterling K. Webb __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
I don't think we have any technology capable of shooting down a satellite. What I guess they'll do is turn it into a debris cloud, and the individual components will separately decay and burn up over the next few months (or years). More junk to dodge. Chris * Chris L Peterson Cloudbait Observatory http://www.cloudbait.com - Original Message - From: Sterling K. Webb [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com Sent: Thursday, February 14, 2008 10:33 AM Subject: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite Hi, The large and unidentified experimental next-generation spy satellite, USA-193, that failed shortly after launch in December, 2006 and was expected to make an uncontrolled and destructive re-entry into the Earth's atmosphere at the end of February, will be shot down while still in orbit, the AP announced about 20 minutes ago. A press conference at the Pentagon to confirm this is expected sometime this afternoon, they say. http://ap.google.com/article/ALeqM5h7aoM2ii3QVBCAV8m2HtJSuPxPNwD8UQ7CEO0 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Gosh- Most of meteorites I collect are micromounts- maybe I can get a macromount of something from space for a change! Might even still be warm... Mike Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite
Hi, One news report says that a Pentagon spokesperson has said that USA-193 will be taken out by an SM-3 missile, and several news reports have made mention of a U.S. Navy cruiser as the platform for the USA-193 takedown. A thorough rundown of the RIM-161 SM-3 Aegis Ballistic Missile Defense system can be found at the following webpage: http://www.globalsecurity.org/space/systems/sm3.htm The Aegis SM-3 is designed as a defense against short- and intermediate-range ballistic missiles. It uses long-wave infrared sensors with a range of 300 km. The KW (Kinetic Warhead) is a self-contained unit with its own solid rocket engines, its own control and guidance system, and its own brain, which is smart enough to discriminate between true targets and decoys, radar- confusing shapes and other defensive measures. Since USA-193 has no defenses nor ability to maneuver, it can safely be considered a sitting duck, I think, and not a match for the SM-3: Discrimination algorithms enable defense systems to compare objects in a target scene to determine which to intercept. Increasingly complex threats with separated target elements, countermeasures, and debris, require advanced signal processing and discrimination algorithms to identify object features needed to provide robust target selection. SM-3 has flown and demonstrated fundamental discrimination capability for unitary threats. USA-193 should be a goner. Compared to the usual target for an SM-3, it's lower, less deceptive, less defended, unshielded, uncloaked, too warm (infra-red, remember?) -- however, it is faster than a shorter- range ballistic missile would be. Will the SM-3 pass the eBay test? That is, no surviving pieces make it to Earth that are big enough to sell on eBay? We'll know in a few weeks. Sterling K. Webb -- - Original Message - From: Matson, Robert D. [EMAIL PROTECTED] To: Chris Peterson [EMAIL PROTECTED]; Meteorite List meteorite-list@meteoritecentral.com Cc: [EMAIL PROTECTED] Sent: Thursday, February 14, 2008 12:57 PM Subject: RE: [meteorite-list] U.S. To Shoot Down Defunct Spy Satellite Hi Chris, I don't think we have any technology capable of shooting down a satellite. What I guess they'll do is turn it into a debris cloud ... A semantic distinction, though I agree it is prone to misinterpretation by the majority of the general public. It's not like shooting down a plane, where all the debris impacts within 20 miles of the intercept. ... and the individual components will separately decay and burn up over the next few months (or years). More like hours or days. This will not be like the Chinese ASAT test, where the target satellite was at a higher altitude. USA 193 is within a few weeks of natural reentry; since the orbit has already been circularized by atmospheric drag, any impulse addition of energy will result in fragments that have higher eccentricity. So a large number of those fragments' orbits will have perigees below 100 km -- in other words, they will decay within one orbit. The only fragments that may end up with lifetimes slightly longer than an unintercepted USA 193 are those which depart the impact point with higher velocity _and_ in directions very close to the plane that is perpendicular to the satellite radius vector at impact. Sorry for the awkward description -- a picture would explain this much better. Another way of stating this is that to survive longer, a fragment's post-impact orbit must have its perihelion close to the impact location. Only a tiny fraction of the fragments will end up this way. And keep in mind that these few fragments will still have perihelions lower than USA 193's altitude at impact, which means they won't last long. Feel free to forward to the met-list... --Rob __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
