A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Space Science Misc
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Hypersonics Overhype



 
 
Thread Tools Display Modes
  #11  
Old April 1st 04, 05:59 AM
Bill Bonde ( Not the man who knows everything, jus
external usenet poster
 
Posts: n/a
Default 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

  #13  
Old April 1st 04, 06:55 AM
Pat Flannery
external usenet poster
 
Posts: n/a
Default 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

  #14  
Old April 1st 04, 03:19 PM
Allen Thomson
external usenet poster
 
Posts: n/a
Default 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.

  #17  
Old April 1st 04, 08:24 PM
Pat Flannery
external usenet poster
 
Posts: n/a
Default 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

  #18  
Old April 1st 04, 08:50 PM
Pat Flannery
external usenet poster
 
Posts: n/a
Default 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

  #19  
Old April 2nd 04, 01:12 AM
Anthony Garcia
external usenet poster
 
Posts: n/a
Default 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  
Old April 2nd 04, 11:06 AM
John
external usenet poster
 
Posts: n/a
Default 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

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 05:17 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.