From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #577 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Thursday, 21 December 1995 Volume 05 : Number 577 In this issue: Waveriders revisited. Satellite Observations Waverider, Whatever Happened to the Satellite Observations - [Corrected Copy] MDC and GD win A-12 law suit Latest Av Week ! 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: Charles_E._Smith.wbst200@xerox.com Date: Wed, 20 Dec 1995 04:10:21 PST Subject: Waveriders revisited. Funny the topic came up when it did. I was going over some flying wing resources sent to me by a friend and one of the magazines had a great article about the B70. I love the B70 because I remember my dad taking me to Wight-Pat as a yoot to go see it. It was soooo cool, and I somewhere have pictures of me as a young guy sitting on the tires- I`ll have to find them. Be neat for the office. I was remembering studying compression lift principles and - -BOOM- it hit me. Almost all new fighter designs use compression lift. The principle of compression lift uses the shock wave(s) from the fuselage to compress the air below the wing. The B70 shows this well. Notice the foward fuselage is symmetrical(ish) and above the wing, whereas the rear part of the fuse- is detached-from the front, and is located beneath the wing. Notice the similarity to the the B70 basic planform when you look at the side-view of the F15, or Mig 29. Also, the F16 shows a similar structure. The LE sweep is chosen to enclose the in the shock cone at the design point Mach number. Pretty cool, huh? I won`t go into all the boring details, but you should get the basic picture. Hope this sheds a little light on the subject. Chuck ------------------------------ From: "Terry Colvin" Date: Tue, 19 Dec 95 16:35:31 EST Subject: Satellite Observations Forwarded interview with Jacques Vallee, astrophysicist: Terry W. Colvin Fort Huachuca (Cochise County), Arizona USA "No editor ever likes the way a story tastes unless he pees in it first." -Mark Twain ------------------------------ From: "Terry Colvin" Date: Wed, 20 Dec 95 07:05:51 EST Subject: Waverider, Whatever Happened to the Forwarded from the Space Tech list: Date: 17 Dec 1995 22:08:04 GMT From: "August,james,a " Subject: Whatever happened to the Waverider? Michael Lammers wrote: >At design conditions, the lateral edges of a waverider will ride >on a captured shock wave. Waveriders often have lower drag, higher >lift, or higher lift/drag ratios than conventional shapes at >hypersonic speeds. I guess the key point here is that they only >have this performance at very high velocities. >From what I understand, the real problem with waveriders is the problem >with a lot of high-performance hypersonic designs -- the darn thing >has got to fly at subsonic velocities at some point to land. Generating >lift at subsonic and supersonic speeds is quite different, and only more >complicated when you are riding shock waves. I believe that most of >the work being done now is to investigate the low-speed aerodynamic >characteristics of wave riders, hence the tests at Ames. From my understanding a waverider shape takes advantage of the leading edge attached shock to act as an endplate, which prevents the high pressure below the wing from leaking into the low pressure above it. This effectively lowers the induced drag which gives a higher L/D ratio. To visualize a simple waverider shape imagine a shock cone (which will be more pointy i.e. larger height to base ratio for higher mach numbers). Now pick a design mach number and using that cone geometry and the desired angle of attack (small) you can get an idea as to what your waverider planform looks like. The problem is that you must keep the rest of the vehicle inside the shock cone or you will suffer high drag and high heat loads (and make more shock waves). You end up with sort of a flattened, curvy shape which has low drag but also low volume. A lack of volume ends up being the big problem with a waverider SSTO. We have low drag, but we can't fit in enough fuel to make orbit (so far). The waverider is a good shape for a cruise vehicle however, since the shape is optimized for a rather narrow range of mach, as are cruise vehicles like missiles or airliners. For more and better info try John D. Anderson's book on Hypersonic Aero or check the NASA RECON database on the web. Jim August UTA/NASA Center for Hypersonics ------------------------------ From: "Terry Colvin" Date: Wed, 20 Dec 95 08:02:31 EST Subject: Satellite Observations - [Corrected Copy] Forwarded interview with Jacques Vallee, astrophysicist: SATELLITES There are many more satellites in low Earth orbit than in geostationary orbit. Any evening or morning, you can see several satellites to the naked eye. MIR comes across at about mag 0. This is as bright as the brightest stars. In the UK, some newspapers used to publish the times of satellite passages in their weather section (!). I used to work at the University of Aston, Earth Satellite Research Unit where these predictions for the press were prepared weekly. Our work was in observing selected satellites with a large camera (huge in fact; 610mm f/1 to those who have an interchangeable lens camera), calculating their orbits and monitoring changes to their orbits due to changes in upper-atmosphere winds and density and also determining the harmonics in the Earth's gravity field (shape to put it simply, but not wholly accurately). Note that most satellites move from west to east (prograde) and in the evening usually move into the Earth's shadow before reaching the eastern horizon. In the morning, they tend to come out of shadow and move towards the east. Satellites in retrograde orbits move from east to west, although most retrograde satellites are only just retrograde (inclination of orbit to the equator of just over 90 degrees) so tend to move more north-south or south- north. A low satellite (say 150-200km height) will cross the sky in a few minutes, but most of this arc is accomplished in about one minute when it is highest in the sky. Satellites with large flat surfaces (like solar panels) can produce substantial glints and it is not uncommon for such glints to reach mag -4 (similar to Venus). There are a few reports of some satellites glinting to even brighter than this, enough to cast shadows. In general, a satellite is brightest when in the opposite side of the sky from the Sun (east in the evening and west in morning) and when close to being in eclipse. During transition into shadow, a satellite can appear quite red if it is bright enough to activate the colour receptors in the eye. Note that there are some groups of satellites that orbit in formation. One is the NOSS group (surveillance of shipping) that has four satellites in close formation. There are several such NOSS formations in orbit. I have seen these by chance on several occasions. If you want to go out and see satellites, there is an excellent Web page that allows you to predict satellite passes for your own site. Try it on http://chara.gsu.edu/sat.html A couple of months ago, there was the first part of a fascinating interview with Jacques Vallee which included how he became involved in UFO investigations. I include these sections again below followed by my comments. There is one thing I wish to make clear. I am commenting ONLY on Vallee's 1961 sighting. The mystery of the destruction of the data is not being considered at all in the following comments. > 50 GCAT: How did you first become interested in UFOs and paranormal >phenomena? > > Vallee: I started out wanting to do astronomy and I ruined essentially >a perfectly good career in science by becoming interested in computers. This >was in France in the early days of computing and the earliest days of >satellites and space exploration. So I took some of the earliest computer >courses at French universities. > > My first job was at Paris observatory, tracking satellites. And we >started tracking objects that were not satellites, were fairly elusive, and ********************************************************************** >so we decided that we would pay attention to those objects even though they >were not on the schedule of normal satellites. And one night we got eleven >data points on one of these objects--it was very bright. It was also >retrograde. This was at a time when there was no rocket powerful enough to ************************************************************** >launch a retrograde satellite, a satellite that goes around opposite to the ***************************** >rotation of the earth, where you obviously need to overcome the >earth's gravity going the other direction. You have to reach escape velocity >in the direction opposite the rotation of the earth, which takes a lot more >energy than the direct direction. And the man in charge of the project >confiscated the tape and erased it the next morning. > > So that's really what got me interested. Because up to then I thought, >Scientists don't seem to be interested in UFOs, astronomers don't report >anything unusual in the sky, so there probably isn't anything to it. >Effectively, I was in the same position that most scientists are in >today--you trust your colleagues, and because you don't see any >reports from credible, technical witnesses, you assume that there is >nothing. And there I was with a technical report--I don't know what it was. >It wasn't a flying saucer--it didn't land close to the observatory. But >still, it was a mystery. And instead of looking at the data and preserving >the data, we were destroying it. > > 50 GCAT: Why did he destroy it? > > Vallee: Just fear of ridicule. He thought that the Americans would >laugh at us, if we sent it--all of the data on satellites was being >concentrated in the U.S. And we were exchanging our data with international >bodies. And he just didn't want Paris observatory to look silly by reporting >some thing that he could not identify in the sky. > [This was in] 1961. Later I found out that other observatories had >made exactly the same observation, and that in fact American tracking >stations had photographed the same thing and could not identify it either. It >was a first magnitude object: it was as bright as [the star] Sirius. You >couldn't miss it. It didn't reappear in successive weeks. ************************************** > It's just a little anecdote, but to me that fact that we destroyed it >was more important than what we saw. And that reopened the whole question for >me: Are there things that scientists are observing and not talking about? And >then I started extending a small network of scientists, which is still >active, and found that there was a lot of data that was never published. In >fact, the best data has never been published. I think a great deal of the >misunderstanding about UFOs among scientists is that the scientists have >never had access to the best data. This is me now again, Rob McNaught. I worked in optical satellite tracking for several years, operating a large camera in the UK and Australia. It seemed unlikely that I could have met and corresponded with so many satellite observers world wide and not have heard of this mystery, so I contacted a couple whom I new were very active. One, Russell Eberst, is I believe the most prolific amateur observer of artificial satellites and he responded thus: "As for Vallee's satellite, I imagine the retrograde object he mentions from 1961 was Samos [2] 1961 Alpha 1. It was 7metres long 1.5metres in diameter and may well have occasionally reached +1 magnitude, though I remember it more around +2.5 There is also a slight chance that if seen after 1961 October, it may have been Midas 4 1961 Alpha-Delta 1 which was launched that month into a high [3500km?] polar, slightly retrograde orbit and was classified by the U.S. for several months. It was rarely naked-eye visibility, though occasionally gave out brief, bright flashes which could catch the attention of anyone staring into the clear dark sky. The reason the team-leader destroyed the observations may have been to ensure the security of the orbit imposed by the U.S. authorities was not compromised. (bit of speculation there)." Vallee said "[they] started tracking objects that were not satellites, were ******************************************************* fairly elusive". This seems rather strange. If you don't have predictions for ************** an observed object, it does not mean that it is not a satellite. If you rely on NORAD, you wouldn't know about the large and very bright Keyhole photo-reconnaissance satellites because they don't publish their orbits. This also applies to NOSS, Lacrosses, Milstars etc. In addition, for every payload there are usually several other objects that make orbit; from the final stage and fairings to unintentional fragments. Not all of these were adequately tracked in the early days. Vallee said: "It didn't reappear in successive weeks." This makes no sense, as *************************************** without knowledge of the orbit, one cannot assume that an object would have visible passes for its non appearance to be an anomaly. Western Europe also has much cloud, so a pass could easily have been missed. It is also possible that the brightness was due to a very low perigee height (closest distance to the earth in its orbit) which is often the case for rocket bodies or fragments from launches which can decay within days of the launch. The object seen by Vallee could perhaps have been 1961 Sigma 2 (the nose-cap of Midas 3), which re-entered 13 days after launch. A satellite which shortly thereafter re-entred would certainly explain the subsequent non appearance. In addition, depending on the inclination, the node of the orbit precesses (like the wobble of a spinning top), taking a satellite through periods of visibility. Vallee said "This was at a time when there was no rocket powerful enough to ************************************************************** launch a retrograde satellite ...". This is simply wrong. Even in April 1959, ***************************** the tenth ever satellite launch, the US Discoverer 2 was launched into an 89.9 degree inclination orbit. Although not quite retrograde, the Thor Agena launch vehicle was clearly capable of reaching a (slightly) retrograde orbit. The earlier attempt at a US military polar orbiting photo-reconnaissance satellite, Discoverer 1, launched in Feb 1959, was not adequately tracked due to the satellite tumbling, but the inclination was about 89.7 degrees. The first retrograde satellite was another US military satellite, Samos 2, launched on 1961 Jan 31 with a 97.4 degree inclination. This was followed by Midas 3 on 1961 July 12 (91.2 degrees) and Midas 4 on 1961 Oct 21 (95.9 deg). The launch vehicles were Atlas Agena A (Samos 2) and Atlas Agena D (the Midas satellites). SAMOS = Satellite And Missile Observation System. MIDAS = MIssile Defence Alarm System Vallee said: "all of the data on satellites was being concentrated in the U.S." **************************************************************** This is also not quite true. The Soviet Union had their own international tracking program and in the UK, a civilian network operated initially out of the Royal Greenwich Observatory and later the Rutherford and Appleton Laboratory. This group collated accurate sightings, calculated orbits and issued predictions of satellite visibility. Following the termination of the US Moonwatch international network of satellite observers, it was very much the British who continued the tradition of visual observations. This message was sent to forteana-digest. Should the message be cross-posted, please copy any comments to rmn@aaocbn1.aao.gov.au I thank Tony Beresford for comments. References: "The R.A.E Table of Earth Satellites 1957-1982" D. G. King-Hele et al 1983 "The Encyclopedia of US Spacecraft" Bill Yenne, 1985 "Artificial Satellite Observing" Ed H. Miles, 1974 "Observing Earth Satellites" D. G. King-Hele, 1983 Cheers, Rob ------------------------------ From: Kathryn & Andreas Gehrs-Pahl Date: Wed, 20 Dec 1995 15:07:05 -0500 (EST) Subject: MDC and GD win A-12 law suit General Dynamics Corp. (now Lockheed Fort Worth) and McDonnell Douglas Corp. have won their law suit against the Federal Government (specifically the Pentagon, represented by the US Navy), over the canceled A-12 Avenger II. Judge Robert H. Hodges Jr. of the U.S. Court of Federal Claims ruled, that he did not need to hear any more testimony, to find in favor of the companies. He decided that the contract was canceled "for the convenience of the government" and not "terminated for default", because the contractors did not conceal information from the Navy (as the USN argued), rather the government failed to provide the contractors with key data about stealth technology, that had already been developed. The court will rule on January 5, 1996, how much the USN has to pay to GD and MDC, which both sued for $1 billion each, even though it is expected that they will receive only about $350 million each. - -- Andreas - --- --- Andreas & Kathryn Gehrs-Pahl E-Mail: schnars@ais.org 313 West Court St. #305 or: gpahl@raptor.csc.flint.umich.edu Flint, MI 48502-1239 Tel: (810) 238-8469 WWW URL: http://www.umcc.umich.edu/~schnars/ - --- --- ------------------------------ From: BaDge Date: Wed, 20 Dec 1995 16:09:52 -0500 (EST) Subject: Latest Av Week ! Hi, The Dec 18th issue of AV Week has the year-end photo contest. Be sure and browse if not buy this issue at your local Barnes & Noble Bkstr., since they stock british mags. Several cool pix, including a knife-edge view of the F-117A, doing a wing-stand, distant topography in the background. If Andreas will pick his fav photo...(hint, hint) regards, ________ BaDge ------------------------------ End of Skunk Works Digest V5 #577 ********************************* To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "majordomo@mail.orst.edu". If you want to subscribe something other than the account the mail is coming from, such as a local redistribution list, then append that address to the "subscribe" command; for example, to subscribe "local-skunk-works": subscribe skunk-works-digest local-skunk-works@your.domain.net To unsubscribe, send mail to the same address, with the command: unsubscribe skunk-works-digest in the body. 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