speed record set by scramjet - fair?

With so little air friction at 100,000 feet, a stone would go quite
far. Give it an aerodynamic shape and it would go even further. I
would only be guessing, but maybe it would go a few hundred miles.

The point is that almost any craft with a propulsion system capable of
moving it at 700 miles per hour would make it to Mach 10 when dropped
from a rocket going Mach 9, provided it was structurally sound enough.
It just sounds to me like an accomplishment that was not in
proportion to the media it got. But I am not an aeronautical engineer
by any stretch of the imagination. So, maybe it really was an
incredible accomplishment and I just don't understand why.

Aardvark wrote in message ...
Don French wrote:

How fast was the rocket going when it released the record-setting
scramjet? If the rocket was going Mach 9 in the thin atmosphere at
100,000 feet and released a stone, for example, the stone would travel
several seconds at close to Mach 9. I assume that the rocket was not
going Mach 9, but I haven't seen any information on how fast it was
going.

Regardless, it seems to me that the rocket's speed has to be
subtracted from the jet's speed to arrive at the actual jet speed when
you talk about the world's record for speed of a jet plane.

-- Don French
Quoted from some web site.

"The telemetry showed the X-43A was set free by the booster at a speed
well in excess of Mach 9 but was able to maintain its cruising velocity
under the thrust from its scramjet.

Engineers followed the X-43A as it travelled more than 1,000km (620
miles), eventually losing speed and plunging into the Pacific. "

Now if the rock went 620 miles after release

"Don French" wrote in message
om...
With so little air friction at 100,000 feet, a stone would go quite
far. Give it an aerodynamic shape and it would go even further. I
would only be guessing, but maybe it would go a few hundred miles.

The point is that almost any craft with a propulsion system capable of
moving it at 700 miles per hour would make it to Mach 10 when dropped
from a rocket going Mach 9, provided it was structurally sound enough.

This thread is hilarious. A bunch of armchair propulsion engineers
pooh-poohing a significant accomplishment in engine technology, none of whom
actually could design a scramjet if their lives depended on it.

Anyway, I certainly think NASA is well within their rights to tout the
success of actually operating a scramjet in flight. It's as revolutionary
as successful operation of the first turbine engine was. What makes the
speed interesting is that no other engine is capable of operating at that
speed. Even if the test vehicle didn't wind up ANY faster than it was when
the engine was started, as long as the engine continued to operate as
designed, it would have been a successful test.

Pete

Jay Honeck wrote:

On a deeper level, I find the enthusiasm about this scramjet flight to be,
in many ways, pathetic.

I mean, c'mon -- we're talking about an unmanned, rocket-assisted, 10 second
flight here -- which is somehow trumped up to be some sort of a huge success
for NASA? Worse, they're claming that they've "beaten the speed record set
by the X-15 some 40 years ago..."


I have to agree, I think this is really only a notch or 2 above a wind
tunnel experiment that went well.

--
Chris W

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Mike Rapoport wrote:
*"Jay Honeck" wrote in message
news:03Umd.45151$V41.23702@attbi_s52...
Regardless, it seems to me that the rocket's speed has to be
subtracted from the jet's speed to arrive at the actual jet speed
when
you talk about the world's record for speed of a jet plane.

On a deeper level, I find the enthusiasm about this scramjet flight
to be,
in many ways, pathetic.

I mean, c'mon -- we're talking about an unmanned, rocket-assisted,
10
second flight here -- which is somehow trumped up to be some sort
of a
huge success for NASA? Worse, they're claming that they've "beaten
the
speed record set by the X-15 some 40 years ago..."

Compare this sad little program to the heady days of the manned
X-15, with
dozens of suborbital flights over a period of years, and you soon
see what
I mean. It's hard to watch this new generation getting all excited
about
a program that, in the 1960s, wouldn't have merited mention on the
nightly
news.

But I suppose that's all they really have to get excited about
nowadays,
with the space program completely shut down.

NASA has sunk so far since I was a boy...it is to weep.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

It typical NASA hype. Note that they claimed to have "invented"
virtually
everything new in the '60s.

Mike
MU-2 *

Well they didn't invent this one.
The scramjet was invented by Australian space engineer Professor Ray
Stalker.

Phil


--
mhquay
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

It typical NASA hype. Note that they claimed to have "invented" virtually
everything new in the '60s.

Mike
MU-2

Well, NASA may not have "invented" everything new in the 60's, but they most
definitely paid for it

"Chris W" wrote

I have to agree, I think this is really only a notch or 2 above a wind
tunnel experiment that went well.

--
Chris W

Bingo! That is exactly what it is intended to be. We don't have wind
tunnels that can do Mach 9, or they would have done this test, and many
more, in the wind tunnel.

Point is, they have an engine that does function with internal supersonic
flow. Now they can think about scaling it up to make it useful.
--
Jim in NC


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"mhquay" wrote


Well they didn't invent this one.
The scramjet was invented by Australian space engineer Professor Ray
Stalker.

Phil

They did make a working, flying version.
--
Jim in NC


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Morgans wrote:
*"mhquay" wrote


Well they didn't invent this one.
The scramjet was invented by Australian space engineer Professor
Ray
Stalker.

Phil

They did make a working, flying version.
--
Jim in NC


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No argument from me. I was just adding a bit of info to the thread.

Phil


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I never said it wasn't a successful test, but the only thing touted in
the media was the speed it achieved and the world record it set for
speed, and attributed that speed to the scramjet, not the rocket.
That was just wrong. The speed was almost entirely a result of the
rocket's velocity and had nothing to do with the scramjet. Seriously,
they could have dropped a Piper cub off that rocket and it could have
maintained Mach 9 for hundreds of miles. Should it get the world's
speed record for prop-driven planes? I think not. And I think that
giving the X-43A a worlds speed record is just as fraudulent.

With so little air friction at 100,000 feet, a stone would go quite
far. Give it an aerodynamic shape and it would go even further. I
would only be guessing, but maybe it would go a few hundred miles.

The point is that almost any craft with a propulsion system capable of
moving it at 700 miles per hour would make it to Mach 10 when dropped
from a rocket going Mach 9, provided it was structurally sound enough.

This thread is hilarious. A bunch of armchair propulsion engineers
pooh-poohing a significant accomplishment in engine technology, none of whom
actually could design a scramjet if their lives depended on it.

Anyway, I certainly think NASA is well within their rights to tout the
success of actually operating a scramjet in flight. It's as revolutionary
as successful operation of the first turbine engine was. What makes the
speed interesting is that no other engine is capable of operating at that
speed. Even if the test vehicle didn't wind up ANY faster than it was when
the engine was started, as long as the engine continued to operate as
designed, it would have been a successful test.

Pete

"Don French" wrote in message
om...
I never said it wasn't a successful test, but the only thing touted in
the media was the speed it achieved and the world record it set for
speed

Who cares what the media says? If you know anything about aviation, you
know as well as the rest of us that the media does a pretty poor job of
getting facts straight, especially for technical issues like this one.

and attributed that speed to the scramjet, not the rocket.
That was just wrong. The speed was almost entirely a result of the
rocket's velocity and had nothing to do with the scramjet.

Todd already pointed out the fallacy of that statement. The fact that the
scramjet *accelerated* to the maximum speed clearly shows that the scramjet
is, in fact, the *entire* source of the speed. It produced enough thrust to
maintain Mach 10.

Your statement is like saying that if you towed a Y*go behind a Porsche and
got it up to 150 mph, that you'd be able to then simply disconnect from the
Porsche and still maintain 150 mph in the Y*go. That's simply not true. A
vehicle that can accelerate to Mach 10 from *any* speed and maintain that
speed is capable, all by itself, of that speed. It's just plain incorrect
to claim that "only the last Mach was due to the scramjet" (or however you'd
like to word it).

Seriously,
they could have dropped a Piper cub off that rocket and it could have
maintained Mach 9 for hundreds of miles.

Hundreds? I doubt it. But more importantly, it would NOT have accelerated
to Mach 10.

Should it get the world's
speed record for prop-driven planes?

In your example, the Piper Cub at no point *maintained* a record-breaking
speed.

I think not. And I think that
giving the X-43A a worlds speed record is just as fraudulent.

Well, I'm sorry your incomplete grasp of the facts makes you think that.
Fortunately, those who have a say in the matter have a better understanding
of the situation.

Pete