From: skunk-works-digest-owner@harbor.ecn.purdue.edu To: skunk-works-digest@harbor.ecn.purdue.edu Subject: Skunk Works Digest V5 #0 Reply-To: skunk-works-digest@harbor.ecn.purdue.edu Errors-To: skunk-works-digest-owner@harbor.ecn.purdue.edu Precedence: bulk Skunk Works Digest Wednesday, 2 February 1994 Volume 05 : Number 000 In this issue: Re: Optical camouflage FBI and the SR-75 Re: Skunk Works Digest V4 #135 Beale flight ops? Re: Ramjet Technology Re: Ramjet technology fallout Pilot Insignia... RE: Optical Camoflage Re: Ramjet Technology 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: Doug Krause Date: Tue, 01 Feb 94 00:44:01 -0800 Subject: Re: Optical camouflage TOM PETRISKO <0004343121@mcimail.com> writes: > I really might be missing something about this, but what does it > matter about having a cockpit illusion. With all of todays modern > defensive weapons, you are only interested in visually or > electronically identifying the aircraft. Even in a dogfight, you > just want to shoot the plane down, not see where the pilot is. Knowing which direction the plane is flying helps a lot. **** Douglas Krause dkrause@uci.edu One yuppie can ruin **** **** University of California, Irvine your whole day. **** ------------------------------ From: TOM PETRISKO <0004343121@mcimail.com> Date: Tue, 1 Feb 94 09:59 EST Subject: FBI and the SR-75 This is wild. In the January issue of Railroad Model Craftsman magazine.They report, that at the Chicago Hobby Show Nov. 3-7,1993. FBI agents appeared at the Testors exhibit to confiscate a plastic model of a military airplane which "did not exist". Has anyone got any more details on this. ------------------------------ From: Thomas Gauldin Date: Tue, 1 Feb 1994 12:48:52 -0500 (EST) Subject: Re: Skunk Works Digest V4 #135 Several years ago, my family and I visited the open house at Pope AFB in North Carolina. One of the highlights was a fly-by of the F117. I recalled that a nickname of the plane was the "wobblin goblin." As the plane flew a runway heading at about 500', I was surprised to see that the plane continually rolled about +-20 degrees around its longituninal axis and seemed to yaw and pitch as well, but on a lesser basis. At first I thought the pilot was merely doing it for effect and to show the upper and lower surfaces to the viewers more clearly. In retrospect, I wonder if my initial impression was correct. The plane is actually flown by computer, with the pilot merely directing the computer in the desired attitude, direction etc. I believe that this is called fly-by-wire with computer override. This should result in a very, very smooth flight unless the program called for something else. I wonder if the roll/pitch/yaw characteristics of the flight I saw weren't part of the stealth characteristics of the plane. In otherwords, they were designed in to the flight pattern. Two things come to mind. First of all, the plane is faceted and the result is angular surfaces. Radar reflects off of those surfaces based on the angle of incidence of the beam. SInce most radars still "scan" the sky, getting a reflection back (return) would be a function of a faceted surface being at right angles to the beam. A good radar "lock" would involve many returns from a surface at right angles to the beam. By rolling/pitching/yawing, the program concedes that at some point in time that SOME surface would be at right angles to the beam and would probably give a return. However, the probablity of this occurring two, three or more times in a row are siginficantly diminished and thus a "lock" is virtually denied. I really wonder if the well discussed coatings are really effective in "trapping" the radar signal of if the real "stealth" features of the plane come from simple faceting of the surface (as opposed to rounding) and the wobbling flight of the plane. Tom Gauldin tgauldin@cybernetics.com FAX (919) 676-1404 ------------------------------ From: "Philip R. Moyer" Date: Tue, 01 Feb 1994 13:56:35 EST Subject: Beale flight ops? Ok, since I'm now going to be living a mere two cup of coffee drive from Beale AFB, does anyone know how to get flight operation information? I'd like to be able to drive up, watch a U-2 or two take off, have a snack, watch them land, then drive home. Any ideas? Also, could any locals tell me good places from which to watch the field? Cheers, Phil ------------------------------ From: larry@ichips.intel.com Date: Tue, 1 Feb 1994 12:04:29 -0800 Subject: Re: Ramjet Technology Garet Jax writes: >An interesting article from the November 93 Airman magazine for your >pleasure. Sorry, don't have a scanner for the images. During the past five years, the National Aero-Space Plane program has advanced ... ... Technologies developed for eventual use in the National Aero-Space Plane aren't limited to the outer reaches of the atmosphere. ... ... When completed it will take off like an airplane, accelerate into orbit around Earth, then return through the atmosphere for a conventional landing. ... Thanks Garet for this posting. Here's some more information about NASP successes: A summary of a 1/25/1994 AEROSPACE DAILY article for discussion purposes: NASP team member Pratt & Whitney reported yesterday that engineers working on the NASP program have run tests proving that an engine can generate thrust at speeds up to 14 times the speed of sound, In a scramjet test article at subcontractor Calspan Corp., the test team, led by P&W engineers, was able to directly measure positive thrust between Mach 8, or 5,400 mph, and Mach 14, or 9,500 mph. Much of NASP's propulsion research remains deeply classified. The successful test series was actually completed on July 7, of 1993 and security reviews precluded making them public until this week. P&W engineers couldn't offer many additional details on the engine, its components, or even whether the engine was full-scale or not. P&W's John Delametter, a project engineer told Aerospace Daily however that "without violating the classification, I can say, it was large," "This was no toy that we ran, by any stretch of the imagination." Previous tests have involved only individual components, working at lower speeds, and using inexact measurement techniques. But this latest test involved an "integrated flowpath". This indciates, and Delametter comfirmed that, an inlet, a combustor and a nozzle were involved in the test configuration, and the test series covered the entire range of conditions that a NASP vehicle would encounter in flight, from altitudes of 90,000 feet to about 125,000 feet. Ted Langston, P&W's NASP program chief said: "We now have proof positive, where previously, thrust could only be inferred from pressure instrumentation". "The data will be used to substantiate the propulsion design system up to Mach 14 and is crucial for the NASP engine concept validation process." Delametter noted that "no one to this point has ever actually measured a thrust increment" at these speeds, so "that in itself is something that we considered" a first. ... The Calspan test series resolved a perennial question "you certainly can make thrust" at those speeds, he said. ... "Given this data (and) this technique, we are not too far off from actually being able to run an engine development program, certainly up to Mach 14, and maybe up to Mach 18." In a recent past AW&ST article, P&W's NASP engine team member Rocketdyne, also reported research with gun-launched tests at Mach numbers of 6-10 with axisymmetric scramjet test projectiles. These tests would allow actual supersonic combustion tests to be run at sea level. There was even a photo of a scramjet powered projectile flying between the muzzle of the gun and the target-trap at Mach 6, if I recall correctly. So given all this great research, AW&ST reported in the 1/10/94 issue that the NASP program, as we have known it in the past, namely a program to develop technology to build two manned scramjet powered flight test vhicles, the X-15 of our generation, was being cancelled. Instead the NASP program is being changed to a technology development program. Of course the worry is that with such a de-emphasis, even the research program could die altogether. NASP is not alone in this problem in fact. As you all probably heard in the past few days (actually on TV last night), the SSTO rocket program, known as DC-X, has been cancelled as well. Even with congressionally approved funds, the money will not be spent. So, in our efforts to reduce defense spending, to solve crime problems and enhance health care, we are throwing out the programs that could be evolved into vital components of future commercial and scientific space efforts. Kind of an immediate, short-term payoff. That's the kind of thing we go for in this country! I guess the aerospace revolutions of the past, that were done with little money and an exploring spirit, are gone forever. It's too expensive! It's much less risky to continue to use what is already there. Take that exploring spirit and write a paper instead! Larry ------------------------------ From: Rich Thomson Date: Tue, 01 Feb 94 13:28:01 MST Subject: Re: Ramjet technology fallout In message garet.jax@nitelog.com (Garet Jax) writes: > NASP Facts: > > Mission: flying testbed and technology demonstrator to improve feasibility > of hypersonic flight while providing part airplane, part space-plane > capabilities. When completed it will take off like an airplane, accelerate > into orbit around Earth, then return through the atmosphere for a conventional > landing. Wasn't the NASP project killed? > Speed: Hypersonic. Orbital speed of 17,500 mph What's this in MACH figures? I forget what the speed of sound is... 3,000 mph? It would be interesting if someone could compare the facts & figures given for the NASP to the best guesstimates of similar figures for Aurora (if known). -- Rich - -- Between stimulus and response is the will to choose. ------------------------------------------------------------------ IRC: _Rich_ Rich Thomson Internet: rthomson@dsd.es.com Fractal Freak ------------------------------ From: Corey Lawson Date: Tue, 1 Feb 1994 13:33:20 -0800 (PST) Subject: Pilot Insignia... I noticed that the F117 driver i saw, some years back, at an air show, had much of the "trim" held on his flight suit with velcro. I ASSumed this allowed the patch, name tag, etc, etc, to be left at base. regards dwp Yes, the patchwork is removable for tactical reasons. If a pilot were to be acquired by an enemy force, such details as to the unit the pilot belongs to, etc., become valuable intelligence information or potentially dangerous to the pilot, if the pilot is in a POW situation and the unit for some reason has been blackmarked by the enemy or whatever... "we haf meny ways make you talk" - -Corey Lawson alfalfa@booster.u.washington.edu "I'm just another bran muffin passing through the colon of time." ------------------------------ From: MP%MPA15C@MPA15AB.mv-oc.Unisys.COM Date: 01 FEB 94 14:29 Subject: RE: Optical Camoflage >Have you ever tried playing some of the flight simulator games? Like >Falcon? I'll go you a couple orders of magnitude better than that. Out here we have a place called Fightertown. They have eight military trainer cockpits and a virtual reality world. Some of the trainer cockpits are full motion simulators but most are static. They have HUD, comm, nav, sounds, several bases and a boat (CVN-36). It's a real blast. It doesn't make me a fighter jock but it's as close as I'm likely to come. ________________________________________________________________________ Mark Perew (714) 380-5484 | To know Unisys Mission Viejo, CA | That which before us lies in daily life, mp@mpa15c.mv-oc.unisys.com | Is the prime wisdom; what is more is fume. cb103@cleveland.freenet.edu | -- Milton, Paradise Lost, VIII ============== "All opinions are mine," sayeth the poster ============== ------------------------------ From: larry@ichips.intel.com Date: Tue, 1 Feb 1994 14:43:36 -0800 Subject: Re: Ramjet Technology In message garet.jax@nitelog.com (Garet Jax) writes: >> NASP Facts: >> >> Mission: flying testbed and technology demonstrator to improve feasibility >> of hypersonic flight while providing part airplane, part space-plane >> capabilities. When completed it will take off like an airplane, accelerate >> into orbit around Earth, then return through the atmosphere for a conventional >> landing. > Rich Thomson asks: >Wasn't the NASP project killed? Yes and no. My earlier post esplained it. I guess there is legitimate concern however, that even the technology development part of the project that theoretically remains, would be even easier to kill now. >> Speed: Hypersonic. Orbital speed of 17,500 mph The speed for the type of orbit that is talked about equates to a approx. sea-level Mach number of around 25. BUT! The Mach number that needs to be attained is actually higher. The pure airbreather (non rocket augmented) SSTO mission has a profile something like the following: Acceleration to approx Mach 26.5 at around 180,000 ft. is the goal. There are constraints on temperature limits (so that the vehicle doesn't get too hot), and also for optimum scramjet performance (so the vehicle doesn't get too cold), on the trajectory through the different layers of the atmosphere. We don't need to go into those right now. At Mach 26.5 and approximately 180,000 ft., the engines are shutdown (no rockets either, except for attitude control) and the vehicle would then pull-up and coast while bleeding off speed into an eccentric transfer orbit. So an overspeed of an additional 1.5 Mach is done to allow some energy loss during the unpowered pullup and coast to the eccentric transfer orbit and the final speed of Mach 25. >What's this in MACH figures? I forget what the speed of sound is... >3,000 mph? No, usually people use an approx speed of sound at sea level of around 700 mph. Mach = Velocity/Speed of Sound. So Mach 25 times 700 mph is 17,500 mph. Just an approx. orbital velocity in terms of sea level speed of sound. Speed of Sound = (Ratio of Specific Heats X Gas Constant X Temperature)** 1/2 As altitude changes, temperature changes, and thus speed of sound changes. Compared to the shuttle, at approx. 180,000 ft., Shuttle is somewhere around Mach 6-8. Of course the goal with the rocket is to do most of the acceleration outside of the atmosphere. But therein lies the difference and the essence of hypersonics! Hypersonics is building technology for vehicles that THRIVE in the air! If you can do that, hypersonics also says that you can pull up into orbit. The two types of vehicles are completely different, have their own plusses and minuses, and should never be compared without taking these differences into consideration. We need to develop BOTH! There are airbreathers with rocket-augmented cycles as well. But that is another story. >It would be interesting if someone could compare the facts & figures >given for the NASP to the best guesstimates of similar figures for Aurora >(if known). Given the types of technology that intelligence agencies like to use, namely technology that will definitely work on time and on budget, and with minimum amounts of people, and the fact that many of the people who are supposed to be working AURORA are not scramjet people, I am skeptical that there is any scramjet on AURORA. Mach 6-7 can be done with a ramjet and for higher speeds, bursts of speed can be done with a rocket. Mid-air refuelling of rocket propellants can even be done. So, although it's possible, I doubt AURORA uses any kind of scramjet cycle. Larry ------------------------------ End of Skunk Works Digest V5 #0 ******************************* To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "listserv@harbor.ecn.purdue.edu". 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