From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #424 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Monday, 18 September 1995 Volume 05 : Number 424 In this issue: GPS/HF GPS- comments and a question Re: Space Gliders Jet Engines Re: GPS Re: Jet Engines Re: GPS Re: GPS/HF Re: Skunk Works Digest V5 #421 Re: Jet Engines Re: Jet Engines Re: Jet Engines Nasty Letters Re: Jet Engines Quick request F-117 on Carriers Re: Jet Engines Re: Jet Engines GPS- comments and a question See the end of the digest for information on subscribing to the skunk-works or skunk-works-digest mailing lists and on how to retrieve back issues. ---------------------------------------------------------------------- From: "I am the NRA." Date: Mon, 18 Sep 95 06:41:07 PDT Subject: GPS/HF [If someone has actually WORKED on the nuts and bolts of GPS, dive in...] >As far as I understand it, it works like this... My understanding differs, in the details... (This is based on comments from "i worked on it" folk in sci.mil, during DS... I may have misunderstood/misremembered.) >Yes, there is only one GPS system, but this system has two levels of >accuracy and security, military and civilian. Yep. >The the civil GPS signal can be accessed by anyone with a GPS receiver and its >accuracy is usually just as good as the mil GPS. Not as i understand it. The civil signal IS the military signal and is normally degraded, specifically by adding psudeo random "dither" to the least significant bits. The key is _psuedo_ random. This means that a properly equipped receiver can _DE_randomize the bits, recovering the accuracy. This is also the reason that a _fixed_ civil style receiver can get mil accuracy: it can average out the dither. (Tho most are not equipped to do so...) >The military GPS signal requires a key-code which a soldier in the field puts >into his GPS reciever and gets the famed 'down-to-the-foot' accuracy of the >GPS. Yep. (He also knows where his head is. 8)>>) >During peace-time civ and mil GPS accuracy are nearly the same. Not as i understand it. Its kept degraded, for nonauthorized users. (The official buzzword is "selective availability on/off": normal is selective availability ON, IE if You Ain't Select, Accuracy Ain't Available.) >Now, in a theater of war, I Don't believe that the signal can be degraded for only certain areas. >such as the Iraq/Kwait area during the Gulf war... My understanding was that during DS a VERY SPECIAL set of circumstances kicked in: 1) "we" did not have enuf proper mil GPS receivers. 2) We needed GPS BADLY, as one sand dune looks like the next (to an outlander...). 3) Intel indicated that Iraqi forces did not have GPS, either version, in quantity. Soooooo Selective Availability was TURNED OFF. ANYBODY got full mil accuracy, which allowed the military to get, rapidly, and use accurately, civil GPS receviers. =========================== Ob Skonk: I was not going to tackle the HF_antenna_on_F117 question, since all i can do is speculate, but its semi expert speculation.... Fact: HF antennas come in varying sorts. Some are compatible with F117, as near as i can tell. Fact: either a probe, or longwire type HF antenna could be "retracted" into a "stealth pocket" on the a/c. This would mean the HF rig would be of limited use, but available for, say, emergencies or transit. Fact: With the Antenna out, and especially transmitting, "stealth" would be degraded. (These are an interesting set of analogies to those OTHER stealth craft, submarines, and their LF/VLF/ELF antennas...) regards dwp ------------------------------ From: TOM GAULDIN Date: Mon, 18 Sep 1995 09:38:08 -0500 (EST) Subject: GPS- comments and a question Being a boater, I have a GPS receiver. I was under the impression, however, that the accuracy was good to about 100' under most circumstances. I was also under the impression that the accuracy would be INCREASED, not decreased under times of war, such as Desert Storm. The accuracy is degraded in peacetime to discourage GPS use by terrorists. The Coast Guard operates LORAN, which is also used by boaters. LORAN is known to boaters as being incredibly accurate for revisiting a particular spot, but not that great for locating exactly where you are. GPS is better for locating where you are, within the 100 of so feet of accuracy, but the location "varies" with time within that radius, so there is little consistency in returning to a favored fishing spot. The ultimate system for boaters is differential GPS, which couples the two. The result is that you know where you are with very little chance of error- down to FEET in most cases. Differential GPS is quite common for boaters, and I presume that it is equally common nowdays among flyers as well. The former Soviet Union had a GPS- type of system as well, I understand. I wonder if it is still operational. If it is, does anyone make a GPS-type of receiver for it? Can it be used by civilians? Thomas A. Gauldin Here's to the land of the longleaf pine, Raleigh, NC The summerland where the sun doth shine, BSRB45A on Prodigy Where the weak grow strong and the strong grow great, FAX (919) 676-1404 Here's to Downhome, the Old North State. ------------------------------ From: "Terry Colvin" Date: Mon, 18 Sep 95 07:47:28 EST Subject: Re: Space Gliders Forwarded from SPACE-TECH list: Date: 17 Sep 1995 17:01:02 GMT From: Bob Mosley III Subject: Does a small space glider exist? In <43b49b$pat@Twain.MO.NET> Steve Schaper writes: > >The Soviets tested such a vehicle. > >There are two theories. 1) a retargetable warhead re-entry >vehicle. > >2) A 'space fighter' launched on a Zenit for a once-around >ASAT mission. .The former was believed to be the more plausible of the two during the Cold War, with the intended target being this little thing we call an aircraft carrier. The idea wasn't so much to deliver a nuclear charge, but to provide a high-speed impact upon the deck of a carrier, going through the bottom, and sinking it without risking a pilot. Of course, with the Cold War now gone - or at least until the Ukraine starts misbehaving again - the true purpose of these flights is believed to have simply been to test the thermal tiling knockoffs the Russians wanted to use on Buran. OM - ------------------------------ Date: Sat, 16 Sep 95 23:36:32 GMT From: Charles Radley Subject: Does a small space glider exist ? This is charles Radley posting. Regarding a space glider. The Soviets did orbit and recover a small space glider. The vehicle was called "Spiral" and it flew several times in the early 1980's. It was launched by a Cosmos SL-88 booster from Kapustin Yar, and splashed down in the Indian Ocean where it was recovered by Soviet naval vessels, and was photographed by the Australian Air Force. The vehicle resembled a small winged lifting body, large enough to carry one or two crewmembers. It flew unmanned in all its test flights. Spiral was developed as a counter to the SDI, and was intended to intercept and attack Space Shuttles in the belief that the Shuttles were deploying SDI weapons. The program was cancelled in the mid-1980's. At least one Spiral prototype is on display at an outdoor air museum near Moscow, where tourists freely photograph it. "Spiral" was designed and tested by NPO Molniya and the TsAGI (Central Aero-hydrodynamics institute. NPO Molniya has proposals to build an orbital space plane called MAKS to be launched off of the back of a large Antonov "Mira" aircraft. MAKS would be propelled by cryogenic hydrogen/oxygen engines, and carry a large external bely tank. However, so far MAKS has no customers or sponsors. I hope this might be of interest to the space plane enthusiasts, whose posting here seem to assume the USA is the only country able to build and fly space planes. Tel (Fax) 1-216-888-3991 (-3992) Cleveland, OH. File Server: Mail-server@tranquest.com Anonymous FTP: ftp.wariat.org /pub/tranq WWW Url = ftp://ftp.wariat.org/pub/users/tranquest.html ------------------------------ From: "Terry Colvin" Date: Mon, 18 Sep 95 07:50:33 EST Subject: Jet Engines Forwarded from SPACE TECH list: Date: Sat, 16 Sep 1995 12:08:00 -0800 From: Raymond Frye Subject: Jet engine first sta DE> Simon Rowland writes: DE> >Why don't people use a jet engine for the primary stage in rockets? Orbital Sciences does (B-52). The former X-15 launch system was made available and is still used. Do to the off center loading and that the plane was designed as a bomber the size of the upper stages are a bit small. The Space shuttle was original launched from an jet powered booster for early experiments (747). Much cheaper than a rocket booster and a much higher load than lifted using the B-52 variant but not orbital. However a much larger orbital vehicle could be launched from this system. D-21 drones have been launched using a SR-71 variant rather than a rocket booster at higher speeds and the military has been launching small non-orbital rockets from planes at various things for some time. So we can, we have, and if you want a small reusable vehicle to get four people up to low orbit with a small amount of gear on demand without regard to most wind and weather conditions, it would seem a good use of current technology. Building a new class of aircraft specifically to replace the big dumb booster would be a major undertaking with the usual surprises and disappointments. Perhaps if you could convince the military they need a fast transport aircraft where the cargo area is removable and usable on site. You could get your big air-breathing booster that's all wings and jets. For now maybe Orbital Sciences Corp., Lockheed-Martin, McDonald Douglas, Boeing, or some other will build a larger craft for that jet NASA uses for the shuttle. It's not a new direction but a path less traveled. Ray raymond.frye@spacebbs.com A jet is just a very low chamber pressure rocket where the oxidizer is unrefined and sitting relatively still, rather than being refined and accelerated in the wrong direction prior to combustion. ------------------------------ From: erebenti@MIT.EDU (Eric S. Rebentisch) Date: Mon, 18 Sep 95 12:09:11 EDT Subject: Re: GPS >Now, in a theater of war, such as the Iraq/Kwait area during the Gulf >war, the accuracy of the civilian GPS signal will be degraded, anywhere >from a few yards to a few kilometers (such as when the fighting began,) >to prevent an enemy from using the civGPS. During the Gulf War, the military planners decided not to encrypt the GPS signal since there were several non-military users who rely upon GPS for navigation (not only the commercial carriers that were hauling war-necessary equipment and personnel, but also civil carriers engaged in non-war activities). They decided that the benefits of the full signal to the Iraqis were neglegible compared with the possible problems of degrading the signal for other legitimate users. BTW, Russia also has their own GPS system - Glonass. Eric ------------------------------ From: Charles_E._Smith.wbst200@xerox.com Date: Mon, 18 Sep 1995 09:18:31 PDT Subject: Re: Jet Engines Don`t really know where to start. Jet engines have a inherent problem for orbital insertion. The goal of an orbital system is to gain velocity. Get the velocity and the altitude will take care of itself. ( You can use the "total energy approach" also, but most of goal is still velocity!) This is where jet engines fail. The thrust of a jet engine (turbo, fan, SCRAM,,RAM, even turboprops) falls off as the velocity increases. This can be easily explained in terms of momentum. The thrust is nothing more than the mass flow rate of air multiplied by the difference between the exit and inlet velocities. Since the Mach number at the exit of the combustion chamber cannot exceed Mach1, the fully expanded exhaust has a finite velocity. Since the exhuast velocity is fixed, as the inlet velocity increases (airspeed) the difference and hence the thrust, decreases with speed. Sooner or later the thrust will decrease to be equal with the drag and you reach top speed. Since jet engines run very lean, the fuel air ratio is usually small enough to neglect the change in velocity for the fuel mass flow rate. (J-79`s NOT included in this assumption!!! Guzzle - Guzzle) On a rocket, the thrust is constant regardless of velocity, since the "inlet" velocity is always zero, and the exhaust speed is constant. Of course, as altitude increases the nozzle will become overexpanded and thrust will start to fall off. When this happens, its time to drop that motor and start a new one. (Well, there are a few other considerations but that is one of the red x`s in the "pi" ratios.) So, for high velocity, you can`t use airbreathing engines. There are no supersonic combustion chambers yet. But believe me , Stephan, Dan and I are working on it. We`ll keep everyone posted if any breakthroughs come up. Excellent Question. Chuck Smith "Aerospace Engineer to the Stars" ------------------------------ From: dadams@netcom.com (Dean Adams) Date: Mon, 18 Sep 1995 10:36:50 -0700 (PDT) Subject: Re: GPS > >Now, in a theater of war, such as the Iraq/Kwait area during the Gulf > >war, the accuracy of the civilian GPS signal will be degraded, anywhere > >from a few yards to a few kilometers (such as when the fighting began,) > >to prevent an enemy from using the civGPS. > > During the Gulf War, the military planners decided not to encrypt the > GPS signal since there were several non-military users who rely upon GPS > for navigation (not only the commercial carriers that were hauling > war-necessary equipment and personnel, but also civil carriers engaged > in non-war activities). Not to mention the fact that a lot of troops were equipped with *commercial* GPS units, since there were not enough military models to go around. ------------------------------ From: Michael Chui Date: Mon, 18 Sep 1995 13:49:31 -0500 Subject: Re: GPS/HF A nice reference for GPS is: http://www.utexas.edu/depts/grg/gcraft/notes/gps/gps.html Differential GPS allows users to achieve greater precision than the 100 m normally available with Selective Availability degradation. A nearby reference beacon with a known position is used to "subtract out" the noise in the degraded signal. Michael Chui mchui@cs.indiana.edu ------------------------------ From: Mike.Mueller@jpl.nasa.gov (Mike Mueller) Date: Mon, 18 Sep 1995 12:01:11 -0700 Subject: Re: Skunk Works Digest V5 #421 Once upon a time, Chuck Smith arranged the phospers on my CRT to read: > >>If you are out traveling the highways this year and come across any of Xerox`s >>new trucks, (the new ones have the red, disintegrating "X"), check out the >>back doors. Some of them will be adorned with a skunk. > >>Why? Well, Xerox decided to benchmark forward product groups for innovation >>and developement-cycle time, and decided that the Lockheed "skunk works" >>during the Kelly Johnson years was the one to emulate. To this end, the >>Xerox "skunk works" was launched. The skunk is added to most of the Webster, >>NY trucks as a tribute to BOTH organizations. Interesting... In the past, Lockheed has protected the Skunk Works trademark and logo with a zest and zeal rivaling Disney's protection of its mouse (there was even an article in the "Lockheed Star" company newspaper about it around 4 years ago). I wonder if Xerox is giving "Lockmart" a break on copier services in exchange for the "tribute" and use of the trademark. ;-) ------------------------------ From: dougt@u011.oh.vp.com (Doug Tiffany) Date: Mon, 18 Sep 95 15:28:34 EDT Subject: Re: Jet Engines Chuck Smith Writes: >The thrust is nothing more than the mass flow rate of air multiplied >by the difference between the exit and inlet velocities. Since the Mach >number at the exit of the combustion chamber cannot exceed Mach1, the >fully expanded exhaust has a finite velocity. Since the exhuast >velocity is fixed, as the inlet velocity increases (airspeed) the >difference and hence the thrust, decreases with speed. Please pardon my ignorance, but it's reasons like this I joined this list. If the Mach number at the exit of the combustion chamber cannot exceed Mach one, then how can the aircraft itself exceed Mach one? That almost seems like a sailboat that can exceed the speed of the wind. It's obvious that I'm not thinking correctly on this one (This one of many :-) ). Thanks for the info!! - -- A hundred years from now, it will not matter what kind of house I live in, how much is in my bank account, or what kind of car I drive, but the world may be a different place because I was important in the life of a child. Douglas J. Tiffany dougt@u011.oh.vp.com Varco-Pruden Buildings Van Wert, Ohio ------------------------------ From: freeman@netcom.com (Jay Reynolds Freeman) Date: Mon, 18 Sep 1995 14:20:59 -0700 Subject: Re: Jet Engines I am sure that someone with more knowledge than I will reply with words to the effect that post-combustion-chamber-exit nozzle expansion can produce speeds in excess of Mach 1, but I also wanted to note that sailboats *can* exceed the speed of the wind. -- Jay Freeman ------------------------------ From: fmarkus@pipeline.com (Frank Markus) Date: Mon, 18 Sep 1995 17:41:04 -0400 Subject: Re: Jet Engines On Sep 18, 1995 15:28:34, 'dougt@u011.oh.vp.com (Doug Tiffany)' wrote: That almost seems like a >sailboat that can exceed the speed of the wind. Sailboats can exceed the speed of the wind. Catamarans (which have relatively little drag) can go MUCH faster. - -- Frank Markus ------------------------------ From: (SSG, ANTHONY, MAA, 565) Date: Mon, 18 Sep 95 12:35:30 PDT Subject: Nasty Letters My apologies for the nasty-grams some of you have received from my server. I was away at the Air Races since Tuesday and my mailbox overflowed. Saw the last RF-4C fly-by the Air Races will ever have, though. Also, had the GeeBee damn near hit the Sani-Hut at the pylon I was at. Got a good picture of it coming at us. A fun time was had by all and no accidents. Did almost have a P-51 land gear up Saturday (oops). Tony ------------------------------ From: Mary Shafer Date: Mon, 18 Sep 1995 18:32:39 -0400 (EDT) Subject: Re: Jet Engines We never launched a real Space Shuttle from the 747. We dropped the Enterprise, during the Approach and Landing Tests, but it wasn't a launch in any real sense of the word. The Enterprise was totally unpowered and never exceeded the altitude from which it was dropped. Also, OSC has purchased and modified their own launch vehicle, an L-1011, and no longer uses the NB-52B. Regards, Mary Mary Shafer DoD #0362 KotFR shafer@ursa-major.spdcc.com URL http://www.dfrc.nasa.gov/People/Shafer/mary.html Some days it don't come easy/And some days it don't come hard Some days it don't come at all/And these are the days that never end.... On Mon, 18 Sep 1995, Terry Colvin wrote: > Forwarded from SPACE TECH list: > > Date: Sat, 16 Sep 1995 12:08:00 -0800 > From: Raymond Frye > Subject: Jet engine first sta > > DE> Simon Rowland writes: > > DE> >Why don't people use a jet engine for the primary stage in rockets? > > > Orbital Sciences does (B-52). The former X-15 launch system was made > available and is still used. Do to the off center loading and that the > plane was designed as a bomber the size of the upper stages are a bit > small. > > The Space shuttle was original launched from an jet powered booster for > early experiments (747). Much cheaper than a rocket booster and a much > higher load than lifted using the B-52 variant but not orbital. However a > much larger orbital vehicle could be launched from this system. > > D-21 drones have been launched using a SR-71 variant rather than a > rocket booster at higher speeds and the military has been launching > small non-orbital rockets from planes at various things for some time. > > So we can, we have, and if you want a small reusable vehicle to get > four people up to low orbit with a small amount of gear on demand > without regard to most wind and weather conditions, it would seem a > good use of current technology. Building a new class of aircraft > specifically to replace the big dumb booster would be a major > undertaking with the usual surprises and disappointments. > > Perhaps if you could convince the military they need a fast transport > aircraft where the cargo area is removable and usable on site. You > could get your big air-breathing booster that's all wings and jets. > > For now maybe Orbital Sciences Corp., Lockheed-Martin, McDonald Douglas, > Boeing, or some other will build a larger craft for that jet NASA uses > for the shuttle. It's not a new direction but a path less traveled. > > Ray > > > raymond.frye@spacebbs.com > > A jet is just a very low chamber pressure rocket where the oxidizer is > unrefined and sitting relatively still, rather than being refined and > accelerated in the wrong direction prior to combustion. > ------------------------------ From: kuryakin@arn.net (Rick Pavek) Date: Mon, 18 Sep 1995 18:43:50 -0500 Subject: Quick request I need a good three-view of the SM-62 Snark, IM-99 Bomarc, Regulus II, and the Nike Ajax and Nike Hercules. There's an old Air Progress that has a Snark drawing.. don't remember which issue, just that it's one I don't have. Clear xeroxes are fine, I'll reimburse expenses. Thanks, Rick Rick Pavek | Get Windows '95!! It's kuryakin@arn.net | the last Microsoft game Graphics and HTML for hire | you'll _ever_ want to Play! http://northshore.shore.net/~wxcentrl/uncle/index.html ------------------------------ From: ConsLaw@aol.com Date: Mon, 18 Sep 1995 19:52:58 -0400 Subject: F-117 on Carriers To continue Megazone's thread on the F-117 and carriers. I wouldn't think from the basic layout of the plane that it would be a very good carrier aircraft, but Grumman proposed a navalized and slightly upsized version of the F-117 as a replacement for the then-newly-cancelled A-12. No one knows more about carrier aircraft than Grumman. It wouldn't surprise me if an arrester hook was fitted to a F-117 on an experimental basis. Also, it is easier to take off from a carrier than it is to land on it. In World War II, in addition to the Dolittle Raiders, P-40s took of from carriers during the invasion of North Africa. In the Marianas, P-47s not only took off from escort carriers, they were catapulted off the ships. I don't know where they attached the catapult harness, possibly the central stores pylon. There was actually a prototype P-51 naval fighter produced. The Navy types didn't like water-cooled engines much, and the P-51 was in demand elsewhere. Of course, on the skunk front, U-2s have taken off from carriers. I don't know if they've landed on the ships or not. Perhaps someone on this list would know. (With that wingspan, I woudn't want to try it. ) The bottom line: From an engineering standpoint, it's not that difficult to modify an aircraft for carrier operations. In addition to adding the hardware for stopping and starting, sometimes there has to be structural strengthening to handle the arrested landings. Some modifications are more successful than others. The best carrier planes tend to be those designed for it from scratch, but if it would serve a vital mission, I wouldn't be surprised if an F-117 has been, or will be modified for the task. >From: megazone@world.std.com (MegaZone) >Date: Sun, 17 Sep 1995 07:07:04 -0400 (EDT) >Subject: Re: Skunk Works Digest V5 #422 >Once upon a time Andrew See shaped the electrons to say... >>I guess this dispels the rumours that F-117's can operate covertly from >>carriers. >Anyone who believed it could never saw it in person. >No naval gear at all. ------------------------------ From: wizard@fs1.houston.sccsi.com (John F. Regus) Date: Mon, 18 Sep 1995 20:52:42 -0500 Subject: Re: Jet Engines > Doug Tiffany wrote: >That almost seems like a sailboat that can exceed the speed of the >wind. This raises a question in my mind about the maximum speed of the airframe, since the maximum speed of a boat is 1.3 * (the square root of the length of the boat), does the same axiom hold true for an aircraft. ************************************************************************* * STRATACOM WORLDNET * internet: wizard@sccsi.com | SYS/370/390 * internet: STRATACOM_WORLDNET@msn.com | Systems Software Engineering * voice: 713-960-0045 | Data and Tele-Communications * fax/data:713-960-0015 | * WUI: REGUSHOU | John F. Regus, Consultant ************************************************************************* ------------------------------ From: BaDge Date: Mon, 18 Sep 1995 22:36:15 -0400 (EDT) Subject: Re: Jet Engines On Mon, 18 Sep 1995, Frank Markus wrote: > On Sep 18, 1995 15:28:34, 'dougt@u011.oh.vp.com (Doug Tiffany)' wrote: > That almost seems like a > >sailboat that can exceed the speed of the wind. > > Sailboats can exceed the speed of the wind. Catamarans (which have > relatively little drag) can go MUCH faster. > > -- > Frank Markus Uh, Frank, is this the same thing? The Cat would be getting 'lift' and riding on an air cushion as well. I have no knowledge about this, just think this is an interesting thread... What would the sailboat be doing, getting an elastic response, or a vector addition, (...duh?) ;-) See ya! regards, ________ BaDge ------------------------------ From: Christopher Beaugrand Date: Mon, 18 Sep 1995 22:53:40 -0400 Subject: GPS- comments and a question > >Lots of stuff about GPS here deleted > As one who has worked with GPS, I can tell you that some of you are right about some of the stuff. First, there is ONE GPS signal. a constallation of satellites transmit their time and location. a receiver gets this information and uses simple triangulation to determine its position. You need 4 satellites for a complete 3-dimensional fix. Why? Because to get accurate readings, you need to have an accurate clock. The satellites have atomic clocks, handheld receivers have Quartz clocks. The fourth satellite is used to keep the time on the receiver correct. Even today with almost all the satellites up, you can't always get 24-hour coverage of an area with 4 satellites. The military move them around so that they can concentrate them where they want them. This was especially evident during the Gulf War. Boats were the first to use GPS before the constallation was complete because they normally didn't need a fix in the third dimension. Unless something was very wrong, they were normally at sea level. Now, the controlling powers introduce random variations in the signal, introducing an error of up to 200 meters or so. To get around this, I believe that the military issue units have the days code preprogrammed. As for ground units, you can still get accuracy within a cm with differential GPS. Differential GPS uses a fixed receiver and a mobile unit. Since one knows the true location of the fixed receiver, you can remove the artificial error introduced as long as the remote unit is within a certain distance of the fixed receiver. As well, Trimble uses other artifacts in the signal to increase their units accuracy. So, I hope that this answers some of the questions, and dispells some of the rumors. ============================================================== Chris Beaugrand Undergraduate Geography Student Queen's University Kingston, Ontario, Canada 3ceb1@qlink.queensu.ca Chris@ams.queensu.ca http://cspo.queensu.ca:8080/~beaugrc Check out the WWW - -------------------------------------------------------------- Live Smart. Think for Yourself. Transform the Future. ------------------------------ End of Skunk Works Digest V5 #424 ********************************* To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "majordomo@mail.orst.edu". 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