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With 'Scramjet,' NASA Shoots for Mach 10
WashingtonPost.com ^ | 11/10/04 | Guy Gugliotta

Posted on 11/10/2004 9:31:28 AM PST by the_gospel_of_thomas

washingtonpost.com With 'Scramjet,' NASA Shoots for Mach 10

By Guy Gugliotta Washington Post Staff Writer Wednesday, November 10, 2004; Page A01

HAMPTON, Va. -- They call it a "scramjet," an engine so blindingly fast that it could carry an airplane from San Francisco to Washington, D.C., in about 20 minutes -- or even quicker. So fast it could put satellites in space. So fast it could drop a cruise missile on an enemy target, almost like shooting a rifle.

Next week, NASA plans to break the aircraft speed record for the second time in 7 1/2 months by flying its rocket-assisted X-43A scramjet craft 110,000 feet above the Pacific Ocean at speeds close to Mach 10 -- about 7,200 mph, or 10 times the speed of sound.

The flight will last perhaps 10 seconds and end with the pilotless aircraft plunging to a watery grave 850 miles off the California coast. But even if the X-43A doesn't set the record, it has already proved that the 40-year-old dream of "hypersonic" flight -- using air-breathing engines to reach speeds above Mach 5 (3,800 mph) -- has become reality.

Unlike rockets, which must carry oxygen with them as a "combustor" to ignite the fuel supply, scramjets take oxygen from the atmosphere, offering a huge savings in aircraft weight, and researchers around the world would like to take advantage.

In northeast Australia, a scramjet team funded by the U.S. and Australian armed forces will try for Mach 10 next year as a first step in using a scramjet to put satellites in space. The U.S. Air Force hopes to demonstrate within five years a scramjet-driven cruise missile fast enough to drive explosives deep into hardened targets. Other projects are moving forward in France and Japan.

...

(Excerpt) Read more at washingtonpost.com ...


TOPICS: News/Current Events
KEYWORDS: nasa; scramjet; technology
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To: Frohickey

To be honest, you do make a very good point. I swear.....I don't give a rip about how much money she has.......I couldn't get drunk enough...........


41 posted on 11/10/2004 3:34:44 PM PST by Howie66 ("America will never seek a permission slip to defend the security of our people.")
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To: RightWhale; Brett66; xrp; gdc314; sionnsar; anymouse; RadioAstronomer; NonZeroSum; jimkress; ...

42 posted on 11/10/2004 5:38:35 PM PST by KevinDavis (Let the meek inherit the Earth, the rest of us will explore the stars!)
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To: Ranxerox

Actually you are describing a Ramjet. A Scramjet technically is a Supersonic Combustion Ramjet, thus a Ramjet where combusion is accomplished without the inlet airflow slowing down to subsonic velocities. Ramjet missiles have flown supersonically since the 50s (Bomarc), but when you don't have to slow the inlet airflow down to subsonic inside the engine, you can gain even faster exit flows, thus faster vehicle speeds.

The benefits of Ramjets and Scramjets over rocket engines is that you don't have to carry your oxidizer with you. Bad thing is that once you get to the upper atmoshere, you don't have much oxygen to scoop up. Going at high mach numbers in the lower atmosphere produces a lot of drag friction heating. And if your goal is to go orbital, you still have to reach exit velocity, which is a lot faster than any Scramjet can go.

Gee, I knew that degree in aerospace would be good for something after all. :)


43 posted on 11/10/2004 7:10:25 PM PST by anymouse
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To: Jack of all Trades
Horse hockey! Velocity has no bearing on perceived weight. Water does not cushion one from the effects of acceleration. Time to hit the Physics books guys.

I always wondered about that. Please explain how a centrifuge can accelerate tubes of whole blood to tens if not hundreds of gravities and the fragile red blood cells are not the least bit damaged. Still viable, usable. Why is a person in a tank of water any different? Seems acceleration would cause the perceived density of the water (perceived pressure) to go higher, but the relative density of the person would not cause excessive pressure against the bottom of the tank.

44 posted on 11/10/2004 8:43:43 PM PST by JATO (The MSM is ORGANIZED CRIME. Conspiracy, fraud, blackmail, bribery. They do it ALL.)
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To: Frohickey
Can we stuff Hanoi John into this sucker? Why? Losers shouldn't be given hypersonic airplane rides. ;)

It's the ditching in the deep blue Pacific that we all have in mind here.

45 posted on 11/10/2004 8:46:01 PM PST by JATO (The MSM is ORGANIZED CRIME. Conspiracy, fraud, blackmail, bribery. They do it ALL.)
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To: monday; hiho hiho

If that's the case, then one of my original assumptions was wrong - oops.


46 posted on 11/11/2004 1:52:13 AM PST by Jack of all Trades (Thank God I voted for Bush - AGAIN!)
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To: orionblamblam

Simplistic - yes. Based on wrong assumptions of hiho hiho's understanding - yes. Wrong? yes and no. In truth, I hadn't even considered the acceleration required to fly at a constant altitude at Mach 10 when I spouted off. As a SWAG, it works out to be a little less than 0.2g Interesting, thanks.


47 posted on 11/11/2004 2:08:40 AM PST by Jack of all Trades (Thank God I voted for Bush - AGAIN!)
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To: Final Authority
The concept of ram jet, later scram jets, was developed in the '50s for missile defense where the flight was one way only.

Wasn't the German "buzz bomb" of the 40's considered a ramjet? In any case it was the first "cruise missile".

48 posted on 11/11/2004 2:37:43 AM PST by Ichneumon ("...she might as well have been a space alien." - Bill Clinton, on Hillary, "My Life", p. 182)
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To: JATO

Undeterred by my earlier misjudgements, and partially in my own defense, I'll give it a go.

The original reply mentioned immunity from the effects of acceleration to which I objected, adding the word cushion. In hindsight, the first two people I replied to probably had a better understanding than I assumed.

In the blood cell example you raised, there are two things going on: low mass and force distribution. Blood cells don't have much mass to begin with so 100X doesn't amount to much. Plus, they're really small so the resulting forces don't have much leverage.

Putting a body against a soft cushion or in a liquid during acceleration spreads out the distribution of forces imparted. As a generalization, it's not force that breaks stuff, it's pressure.

I've seen the same principles at work in optical encoder components that undergo very high shocks. They don't break because they're really small, really light, and there's a drop of gorilla snot inside each one.


49 posted on 11/11/2004 2:42:06 AM PST by Jack of all Trades (Thank God I voted for Bush - AGAIN!)
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To: the_gospel_of_thomas
So fast it could drop a cruise missile on an enemy target, almost like shooting a rifle.

Camels and tents : watch out...


BUMP

50 posted on 11/11/2004 2:49:01 AM PST by tm22721 (In fac they)
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To: the_gospel_of_thomas; Brett66; KevinDavis; Happy2BMe; devolve

With 'Scramjet,' NASA Shoots for Mach 10
http://www.freerepublic.com/focus/f-news/1276446/posts

Wow! That's MOVIN'!!


51 posted on 11/11/2004 5:48:54 AM PST by MeekOneGOP (There is only one GOOD 'RAT: one that has been voted OUT of POWER !! Straight ticket GOP!)
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To: anymouse

Yeah, I've read that the scramjets won't have very useful civilian applications, they will be great for cruise missiles though. I think the odds of us seeing a passenger jet based on one of these are about as great as seeing a passenger space shuttle taking tourists to LEO.

Save your money to buy a ticket on Virgin Galactic.....


52 posted on 11/11/2004 5:53:54 AM PST by Brett66 (W1 W1 W1 W1 W1 W1 W1 W1)
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To: Jack of all Trades

This should be easy to test. Put a volunteer, or a chimpanzee, into a centrifuge with breathing apparatus suitable for REALLY high pressure diving. Fill the compartment with... not water, but something as close to the density of a human body as possible.

Then... SPIN!

I'd bet the subject could withstand at least 30 G's.


53 posted on 11/11/2004 7:07:48 AM PST by JATO (The MSM is ORGANIZED CRIME. Conspiracy, fraud, blackmail, bribery. They do it ALL.)
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To: anymouse
Actually you are describing a Ramjet. A Scramjet technically is a Supersonic Combustion Ramjet, thus a Ramjet where combusion is accomplished without the inlet airflow slowing down to subsonic velocities.

No, what I described was a Scramjet. Just because the flow passes through a shockwave (or a series of shockwaves) does not mean it slows to subsonic speeds (as in a ramjet). For an oblique shockwave, only the component of the flow normal to the shock is slowed to subsonic. So the flow will be slower than before, but it can still be supersonic. It all depends on the internal geometry of the engine.

54 posted on 11/11/2004 7:19:45 AM PST by Ranxerox
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To: Ranxerox

Technically you are right, but I was trying to keep the explaination at a level that non-aero-heads would understand. :)


55 posted on 11/11/2004 10:20:54 AM PST by anymouse
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To: JATO; Jack of all Trades

53 - Considering that centrifuges are used to separate things of different densitites, putting an animal in liquid in a centrifuge should work pretty well, like a human. And after centrifuging at 30 g's or what ever, the teeth should be in one level, the bones in another level, the lungs and stomach at another level, and the blood and plasma at another level, etc.

Sounds interesting, and yes, the teeth and bones would probably survive.


56 posted on 11/11/2004 10:51:19 AM PST by XBob (Free-traitors steal our jobs for their profit.)
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To: XBob

the densities aren't that different. You're 99% water... more or less.


57 posted on 11/11/2004 2:41:11 PM PST by JATO (The MSM is ORGANIZED CRIME. Conspiracy, fraud, blackmail, bribery. They do it ALL.)
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To: anymouse; Ranxerox
Huh?

Really, though, I'm not that familiar with jet engines. Reciprocating and rotaries I think I understand but not jets. What's the advantage to moving air through the engine faster - does one get higher thrust out of it? How does one start one of these - wouldn't the air have to already be moving through the engine at that speed before turning it on?

58 posted on 11/11/2004 2:50:36 PM PST by Chemist_Geek ("Drill, R&D, and conserve" should be our watchwords! Energy independence for America!)
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To: Final Authority
There is a simple reason why the test flights are only designed to last about ten seconds, material has yet been developed to withstand the forces and the temperature for longer flights.

If they can get it into a small package, ten seconds would be plenty for an air-launched anti-ship missile. Less fuel weight equals more warhead size for the same total weight

59 posted on 11/11/2004 2:56:41 PM PST by SauronOfMordor (We are going to fight until hell freezes over and then we are going to fight on the ice)
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To: JATO

57 - "the densities aren't that different. You're 99% water... more or less."


Mostly less, here are two quotes from the net, you can find more, but, one thing is certain, the human body is not 99% water, and each organ has different densities, and don't forget air. Just how dense are your lungs, mouth, stomach, esophagus, intestines, etc, and how much would they compress and separate.

Quotes:
- Up to 60 percent of the human body is water, the brain is 75 percent water, blood is 82 percent water, and lungs are nearly 90 percent water.

"Twenty five percent of the human body is solid matter and 75 percent is water states F. Batmanghelidj, MD, author of 'Your Body's Many Cries For Water'. "The brain is said to be 85 percent water." Human blood is 90% water, muscles are 75% water, the liver is 82% water and our bones are 22%"


60 posted on 11/11/2004 4:02:17 PM PST by XBob (Free-traitors steal our jobs for their profit.)
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