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Hypersonics Overhype
Rand Simberg wrote:
On Wed, 31 Mar 2004 13:08:02 -0800 (PST), in a place far, far away, h (Rand Simberg) made the phosphor on my monitor glow in such a way as to indicate that: If a NASA PAO generated the same statement about X-43A, you'd be among the first to crawl all over them for making a 'failure' a 'sucess'. If I had been aware, yes. I'll research further and see if I can rectify it. Thanks for the correction. OK, Derek, you're going to have to provide a cite for your claim, because I can't find any references to it. Everything I find indicates a test success. The ABC thinks it was a success: http://www.abc.net.au/science/slab/hyshot/default.htm #begin quote did the test go? On July 30, 2002 the University of Queensland HyShot team culminated many years of work when they sent their second scramjet payload up into the atmosphere on the back of a Terrior Orion rocket in a test flight. They made history - it turned out to be the first successful launch of a scramjet in the world. The staged Terrier Orion rocket and UQ payload on the launch pad at Woomera. (Courtesy: The University of Queensland.) The dramatic TV footage of the Orion-Terrier rocket actually doesn't show the scramjet working - the rocket is simply there to get the scramjet up into the air and moving quickly. The two-stage rocket used aluminium powder and ammonium dichromate, solid fuel like a Lilliputian Titan 4, to send the payload right up into space, to 314 kilometres. The timing of the launch had to fit around what else was out in orbit. At one stage they had to wait because the projected path of the rocket was within a few thousand metres of the orbit of an American satellite - too close to take any risks! On the day, everything went to plan. The first stage rocket burned for six seconds, accelerating the craft to Mach 3.6, or 3.6 times the speed of sound. That ran up the sky, leaving a white trail behind that stopped halfway up the sky, and then the roar reached us, standing out on the plain, several kilometres away. This was a 16-second silent pause while the slim second stage and the payload slipped free of the spent initial stage. The second stage sits on top of the first stage, and simple drag caused the first stage to fall behind. The business end, the slimmer second stage and its payload, coasted upwards, losing speed from Mach 3.6 back down to Mach 3.2, stabilising any flutters from the first blast. It also pushed through the worst of the lower atmosphere before the second stage rocket kicked in, high in the sky, boosting it up to Mach 7.7. The second rocket blast took it to 56 kilometres above the Earth, just 39 seconds after the scramjet took off. It then simply coasted to the top of the parabola. This is 'going ballistic' in the scientific form of the word. When it levelled out it had been flying for just over four-and-a-half minutes. Gravity kicked in and it tilted and began to plunge back to the atmosphere. By the time the turn was completed, three minutes later, it was almost halfway down to the ground again. We have scramjet! Oh, what a feeling... members of the successful HyShot team (from left) Judy Odam, Dr Ross Paull, Bert Paull, Dr Allan Paull, Dr Susan Anderson, Myles Frost, Suhee Won and Aggie Branczyk. (Courtesy: The University of Queensland.) As the air thickened, the rocket and the passenger scramjet slowed to Mach 7.6, and more oxygen began to pass through the system. At 35 km up in the air - about three times the height jetliners fly at - the scramjet kicked in, just as it disappeared over the horizon, as seen from the control block. The payload was sending data back to receivers on Earth from 40 channels different channels including pressure readings, temperature readings, acceleration measurements and magnetometer readings. The rocket flew as it should, and the scientists tracked it down range and retrieved the telemetry back from the other end to make sure that everything went to plan. The remote stations were in contact with the base by satellite phone, and so the remote stations knew where to point their equipment in order to find the craft as it hurtled towards them at Mach 7.6. So from a first generation of toxic rockets to a generation of slightly less toxic reusable craft like the Shuttle, now we are turning to the third generation of space lift, in the form of a scramjet. The scramjet flew for just six seconds, but then the first flight by the Wright Brothers only lasted 12 seconds, and Robert Goddard's first rocket flight in 1926 lasted just 2.5 seconds, so that would seem to place the scramjet in the middle of the duration span for historic space and flight exploits. Certainly, as one of the University of Queensland people told me over dinner when I mentioned Jonathan Swift, the achievement was by no means Lilliputian. History will be the judge, but I agree. #end quote |
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Hypersonics Overhype
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#13
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Hypersonics Overhype
Derek Lyons wrote:
"Uddo Graaf" wrote: I myself even have doubts about the military applications for the hypersonic bomber the Air Force is envisioning. The goal is to have almost zero decision-to- impact time but a hypersonic vehicle can hardly loiter around Why not? I think it's far more likely to end up as a propulsion system for a missile rather than a manned bomber- we've probably already done work on a rocket-boosted silo-launched scramjet cruise missile under the "Teal Dawn" program. (whatever "Teal Dawn" was, it was supposed to come out of a Minuteman silo, be stealthy, have a range of around 6,000 miles, and apparently worked... it's listed as a "past success" he http://www.dtic.mil/labman/projects/lqip/dsb/dsb3.html ....it is also just about impossible to find information on, even though it was scheduled for operational deployment in the late 1990's) Pat |
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Hypersonics Overhype
Pat Flannery wrote
I think it's far more likely to end up as a propulsion system for a missile rather than a manned bomber- we've probably already done work on a rocket-boosted silo-launched scramjet cruise missile under the "Teal Dawn" program. (whatever "Teal Dawn" was, it was supposed to come out of a Minuteman silo, be stealthy, have a range of around 6,000 miles, and apparently worked... it's listed as a "past success" he http://www.dtic.mil/labman/projects/lqip/dsb/dsb3.html ....it is also just about impossible to find information on, even though it was scheduled for operational deployment in the late 1990's) Could you post the source of the above, please? I didn't find it in a quick look around, but this did come up: From Jim Karam's page, http://www.karam.com/Photo_Gallery_Core.htm [Picture of] Convair's AGM-129A Advanced Cruise Missile, a direct descendant of one of my DARPA initiatives that was nick-named Teal Dawn[*]. Gee, I wonder where he came up with that name? And, no, this picture is not upside-down and backward. Also, don't let anyone tell you how easy it is to design forward swept wings because of today's powerful analytic software. [*] points to picture of his daughter, Dawn Which his resume http://www.karam.com/Jim_Karam's_Resume.htm dates: Program Manager, Strategic Technology Office, Defense Advanced Research Projects Agency, Rosslyn, VA (1975-1978) Conceived & executed three major advanced cruise missile technology thrusts (approx. $15M annually). "Zero-CEP" guidance incorporated active (laser & mmw) & passive sensors with sophisticated image processing. Demonstrated compound rotary and reciprocating engine concepts for reduced fuel consumption, small propulsion. More survivable airframes used radical shaping and new advanced materials, i.e., the beginnings of "stealth". Several eventually entered Full Scale Development and/or production by the Air Force and Navy. There's also a short write-up on pdf p.73 of http://www.darpa.mil/body/pdf/transition.pdf ADVANCED CRUISE MISSILE A DARPA program, TEAL DAWN, developed key technologies and a design later incorporated into the Air Force Advanced Cruise Missile (ACM). In the early 1980s, the Air Force assumed responsibility for the ACM Program and successfully managed the system through concept demonstration; engineering and manufacturing development; production; and development. The TEAL DAWN Program involved a series of studies and developments related to the development of a long-range stealthy strategic cruise missile. DARPA experience in low observables was incorporated into the design of the low-signature engine inlet and nozzle. Other technologies included the unique aerosurface sweep angles that provided a benefit to the aerodynamic performance. Clearly recognized performance goals (signature, range, flight profile)were successfully demonstrated during the DARPA phase of the program. Wind tunnel and radar ranges testing also were accomplished by the Air Force under DARPA sponsorship. The follow-on Air Force program could then focus on operational test and evaluations (OT&E) and manufacturing objectives with a high degree ofconfidence that program objectives would be realized. |
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Hypersonics Overhype
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#16
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Hypersonics Overhype
On Thu, 1 Apr 2004 09:48:52 -0800 (PST), in a place far, far away,
(Derek Lyons) made the phosphor on my monitor glow in such a way as to indicate that: (Rand Simberg) wrote: Well, hypersonic combustion is hypersonic combustion. Sounds like scramjet in flight to me. That's no in conflict with my column. Only if you are willing to play word games. Hence my point about twisting to slam NASA. rolling eyes I didn't "slam NASA." |
#17
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Hypersonics Overhype
Allen Thomson wrote:
Pat Flannery wrote I think it's far more likely to end up as a propulsion system for a missile rather than a manned bomber- we've probably already done work on a rocket-boosted silo-launched scramjet cruise missile under the "Teal Dawn" program. (whatever "Teal Dawn" was, it was supposed to come out of a Minuteman silo, be stealthy, have a range of around 6,000 miles, and apparently worked... it's listed as a "past success" he http://www.dtic.mil/labman/projects/lqip/dsb/dsb3.html ....it is also just about impossible to find information on, even though it was scheduled for operational deployment in the late 1990's) Could you post the source of the above, please? In the book "Unguided Weapons"* (Fen Osler Hampson, W.W. Norton & Company, 1989, ISBN 0-393-02628-0) p.196. It reads: "Since 1980, The Defense Department's Advanced Research Projects Agency (DARPA) has been pushing ahead with "Teal Dawn" , a program to integrate Stealth radar-evasion techniques into an advanced cruise missile (ACM) design. The system would be launched vertically from a Minuteman silo or equivalent and then fly on a horizontal path at supersonic speeds toward its target where, just before hitting the target it would go into a ballistic trajectory (37) the air force envisions acquiring about 1,500 advanced cruise missiles, although the final number would depend on whether the new missile would be available soon enough to interfere with the existing AGM- 86B program. The ACM would have a range in excess of 6,000 miles, enabling it to be fired from U.S. airspace. The aim is also to develop a maneuverable system that would be able to evade Soviet air defenses. In early 1987, Secretary of Defense Casper Weinberger announced that a site had been chosen for the stealth missile and that the new missile would begin arriving at the base by 1989, although deployment would not begin until later in the 1990s (38)" Citation (37) is to p. 210 of " The Evolution of the Cruise Missile" (Kenneth P. Werrell, U.S. Government Printing Office, September 1985); citation (38) is to p.1 of "Current News" (Department of Defense, January 7, 1987 edition). There seems to be something odd going on in regards to what is being discussed here. The first part describes a missile of markedly different conception than the AGM-129A Advanced Cruise Missile; which is air launched, subsonic, and has about a third of the range: http://www.strategic-air-command.com...CM_missile.htm What the description in the first part sounds like is the Hypersonic Glide Vehicle: http://www.astronautix.com/craft/hgv.htm This technology relied on rocket propulsion to get the missile into its glide path; but under the new HyTech and HyFly programs, scramjets are being used: http://www.globalsecurity.org/milita...ons/hytech.htm http://www.globalsecurity.org/milita...ions/hyfly.htm ....and the program tested a dual mode scramjet driven by conventional fuels in a wind tunnel test at Mach 6.5 and a simulated 90,000 foot altitude back in 2002 (above article)....and in fact this program appears to mirror the NASA X-43 program to such a degree that the cancellation of the X-43C program seems a wise move so as not to unnecessarily duplicate research both in the military and civilian spheres. Here's a painting of a F-15 launching a small X-43 looking scramjet missile: http://www.space.com/images/h_hytech missile launch_02.jpg .....and a photo of the dual mode Pratt and Whitney scramjet: http://www.space.com/images/h_prattw...ersonic_02.jpg The military programs use fuel to cool the scramjet and vehicle at cruising speed, so as to avoid the need for expensive (and fragile) materials and complex construction techniques such as those used on the Shuttle's TPS- the test and operational missiles will apparently rely on titanium and nickel alloy for their airframe construction. Pat |
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Hypersonics Overhype
Pat Flannery wrote:
In the book "Unguided Weapons"* (Fen Osler Hampson, W.W. Norton & Company, 1989, ISBN 0-393-02628-0) p.196. Whoops, forgot the *! The book concerns the history of weapons purchases by the Pentagon during the 70's and 80's, and how politics affected weapon buying decisions for good or ill. Pat |
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Hypersonics Overhype
"Bill Bonde ( Not the man who knows everything, just the man who knows the
important things )" [snip] The ABC thinks it was a success: http://www.abc.net.au/science/slab/hyshot/default.htm [snip] and it was (assuming it operated in SCRAM mode) because the stated purpose was supersonic (in the engine) ignition and combustion in the engine. However it was flight only in the barest sense of the word. The accomplishment of the X-43 is more than just the supersonic ignition while in the hypersonic flow regime, it was also controlled flight and computer model validation of the flight models. All of this is not to minimize the Australian accomplishments, they are/were worthwhile. Do not however minimize what occured with the X-43. |
#20
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Hypersonics Overhype
"Pat Flannery" wrote...
Whoops, forgot the *! The book concerns the history of weapons purchases by the Pentagon during the 70's and 80's, and how politics affected weapon buying decisions for good or ill. Can someone please tell me how something that's broadcasting that much IR can be called 'stealthy'? John |
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