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A Million Bucks, Mach 7.6, Straight Down
Dspiral writes "At the Canadian publication, The Globe and Mail, they
write about the scramjet.
A jet engine, with theoretical speeds over 8000 Kph, and pollution free!" Zero pollution because its fuel is hydrogen
(a scramjet
takes its oxygen from the air).
The HyShot homepage
is amazing; the beast has been built on a shoestring, barely over a million dollars Australian, and my favorite part is their planned test:
"...shooting an engine into the atmosphere on a rocket, and hoping it will ignite as it plunges back down to Earth. Mr. Paull's speed objective is Mach 7.6, and the engine should ignite 23-35 kilometres off the ground."
From the HyShot home page: "Developing an engine with net positive thrust is the subject of future flight trials. " Now I see why it only cost a million bucks.
It was the major British missile-testing range in the 1950's and '60's, so it's no stranger to high-Mach crashes (especially the disastrous ELDO European launcher program; oh well, at least the Ariane project found out from it what *not* to do!!!). Similar flights to this experiment were done during the Black Knight project, where a rocket was fired out of the atmosphere, then back down, with the added twist that a second stage rocket was fired on the way *down* to accelerate it! The purpose was to test ICBM/IRBM re-entry cones, so I imagine they came down a *lot* faster than Mach 7.6.
I believe it was some of the most important work done at Woomera, and assisted the development of ablative coatings in the US Mercury manned capsules as well as re-entry cones on the first generation of US ICBMs.
My great dream as a kid was to work there, but its glory days were over by 1980. Now it's used as holding area for illegal immigrants... Ironic, innit; when I was a kid Woomera was a symbol of how far Australia had come since being founded as a prison. Now it's a prison itself :-(
The NASA project I think will be being launched from a B52 aboard a Pegasus rocket, so it still needs a boost.
Of course, there's also the question of whether a scramjet is a good idea at all. It needs hydrogen, which is one of the least dense rocket fuels out there, which makes the structure larger for a given payload (which is bad); also, since a scramjet needs to hang around lower in the atmosphere than a rocket, it's subject to much higher aerodynamic forces and heat loads. Finally, the engines thus far designed have weighed more than the oxygen they're replacing. When you consider how cheap liquid oxygen is, a lot of people wonder, why bother?
(currently testing something about signatures here)
What I like about that is uses a reusable and enviromentaly friendly fuel. Also it has no need for an extra oxygen tank so it is lighter. This is really cool.
This is kind of cool, but I really wonder if anyone is really interested in making hypersonic passenger vehicles. Wasn't the X-30 (or something) cancelled?
:)
Of course I bet if it costs $1M Aus to make, it will cost the US Military about $50M US to make.
oooo free cheers for Mr. No it All and my ass is so tight I cant' see I joke if it got up and bit me
yea I really like my brains in the back of my head. reminds me of the Ren and Stimpy episode " must saaaaavve braain"
didn't they used to attatch these things to helicopter rotors. The Rotors were powered by a minimalist engine then as they began to turn the air forced through the system would be mixed with some fuel and come shooting out the other side. very simple design my question is it only works most efficiently at lower altitudes as opposed to space since they require O2 from the atmosphere. Not only that they require an initial velocity to get them going. I can see it now tomohawk missles being launched off the USS Nimitz with large elastic bands.
Yes, it's much better to fly in a jet filled with highly-flammable kerosene....
Two thirds of the Hindenburg passengers lived, which is a better record than a lot of airliner crashes.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
The concept has been around for a long time. Paper designs aren't new. But real, flying scramjets are another matter.
Ramjets that slow the air to subsonic speeds before combustion are old hat, of course.
err I meant 80's obviously ;)
or a darwin award ;)
"Man and car missing in Illinois"
"Illinois license plate found in Australia"
(20 years later)
"1990 Volvo Stationwagon found in the Mariana Trench"
My plan is to pimp before they realize I'm a jackass. Hit 'em hard and fast.
Maybe not, but they belive in image tags
The page actually reads under lynx
(and any pointers to getting X 6.4.1 to run on a
Toshiba Satellite Pro 420CDT?)
Lord Bhaal
Uh, Enterprise was never slated for space flight. It was retrofitted for space flight after Challenger was lost. Never for a moment did anybody think that the 747 was going to be the first stage of a launch vehicle, since the Shuttle carries about zero fuel for its main engines onboard. The Shuttle was designed from the outset to ride up on the external fuel tank and its SRBs. The 747 was used for glide testing with the Enterprise, and also to transport the operational shuttles back to Kennedy when they land at Edwards AFB.
Why yes, I AM a rocket scientist!
Nope. Won't work. 1) To get to orbit, you have to go through a band (commonly called "space") where there's no oxygen around to combust. If you ain't got any with you, your motor turns off and you turn into a very expensive lawn dart. 2) Nobody's figured out how to get the same hunk of metal (the "engine") to operate both as a ramjet and as a rocket, so you need more hunks of metal inside your spacecraft to get through "space". 3) Scramjets have a very high cross-sectional area relative to their thrust potential compared to rockets. That is, they produce far more drag (up to an order of magnitude more) than a similarly powerful rocket.
High speed air breathing flight is STUPENDOUSLY difficult. It's only been in the last five to eight years that the computers are fast enough to even BEGIN to model the supersonic flows through a scramjet, and the problem is very far from being solved. Rockets are ugly and pedestrian, but they do the job better than any technology on the drawing boards.
Why yes, I AM a rocket scientist!
Didn't you ever wonder why the SR-71 has all those corrugations? That is the design, when it is hot the joints seal.
Pretty cool if you ask me, and this from 1960 tech.
Too bad the XB-70 never made it into production, it was cooler on all points, and a much cleaner aerodynamic design.
You must be fun at parties.
Gasoline is far more dangerous than hydrogen.
One of the old scifi magazines by chance?
A Hawk Among Sparrows?
That story has haunted me since I read it.
http://www.bullnet.com
That's right. They have carefully designed it to run out of fuel just before it hits the ground.
MrCreosote Meow!Thump!Meow!Thump!Meow!Thump! "You're right! There isn't enough room to swing a cat in here!"
"Cut to Sydney Harbor [Fireball blasts upwards behind opera house.]"
You mean like this? Note this comes from the album 'Red sails in the sunset' by that very fine aussie band Midnight Oil. One of their better albums by the way.
MrCreosote Meow!Thump!Meow!Thump!Meow!Thump! "You're right! There isn't enough room to swing a cat in here!"
How fast can a plance accellerate before the average business traveller will lose conciousness from the g-force?_ _____________________
_______________________________________
___ This sig is in boldface to emphasize its importance!
At mach 7.6 it will reach the ground in no time! How will they slow it down? How will it, "stop".
They're going to throw a planet at it. That'll stop it real good.
Hydrogen is pollution free, and will be a huge part of energy storage once we convert from fossil fuels to clean nuclear power.
Yeah, when NASA sends something straight down at Mach 7.6, it costs way more than a million bucks. And sometimes it doesn't even achieve Mach 7.6 on impact.
Anyone want a couple of slightly-used Mars probes?
I left my Doctorate in Rocket Science in my other pair of pants. Any interesting/useful links on rocket fuel consumption?
Later
Erik Z
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
How do you bench test something that needs to be traveling at mach 1 to operate?
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
That why it's called a Supersonic Combustion Ramjet!
"I'm an old-fashioned type of guy. I worship the Sun and Moon as gods. And fear them."
Yeah, given we're already too busy looking out for Mir if it ever comes down....
--
Consultancy: If you're not part of the solution, there's money to be made in prolonging the problem
The "zero pollution" claim is a bit dubious. When the ydrogen fuel it uses is burnt, water vapour results. Of course, water vapour is produced naturally and falls back to the earth's surface as rain.
Unfortunately, water has one of the highest specific heats of atmospheric gases. Some information I have seen (I forget exactly where) labels water vapour as a much worse green-house gas than carbon dioxide.
All in all, I would rather have our atmosphere contaminated with water than with CO2. In high concentrations, we just get hotter, more humid days. With CO2, breathing becomes labourious.
True, but O2 weighs ~ 24 times that of H. I would think the weight cutting benefits would be just as enormous... someday... :-)
Oh.
Wait.
Check out my diary.
"Two flights are planned for the late in 2000."
and at the bottom of the page,
"Modified:19 June 2000"
did they all just forget or something.
Maybe the new Australian cencorship laws kicked in, and they werent allowed to publish anymore info.
Rocket=Phalack symbol????
"Cleared for takeoff, Bumthruyourmouth Air 993...oh , and cleared to land too."
Think, air rage would be a thing of the past if everyones lips are flapping behind their heads and they're unable to move due to the sheer force of takeoff.
So true, so very true...
kugano
I'm no fan of off-topic First Posters, but how can a first post be called Redundant?
Nipok Nek
Why choose white shoes?
Alas, they only claim 11.5k/s for their champaigne cork - the 40k/s figure is for the wild corks presumed to exist in the jovian system.
Wer mit Ungeheuern kämpft, mag zusehn, dass er nicht dabei zum Ungeheuer wird.
This is a university project.
-- veni vidi nuclei deceri --- I came, I saw, I dumped core.
Ramjets and scramjets are wonderful. But they're plagued by one problem: they're only efficient at speeds over 3 or 4 hundred miles per hour (depending on the configuration, type of engine, etc).
So you need to speed up the damn thing for it to work properly. Booster rockets work well for this, so they'd have to use those.
Btw, the V2 rockets used by Germany in WWIV used ramjets, if I'm not mistaken. I guess they just made them a bit faster now.
bart
Ramjets are basically a pipe which is closed on one end during combustion to produce thrust.
This happens at a pretty high frequency, depending on the how efficient the combustion is.
So you need air to make this thing work. You need fuel, which you carry already. If you wanted to travel in space, you'd need to carry oxygen, too, and keep one end permanently closed. So you end up with a rocket.
Oh well. No space travel with these babies.
Use The Source, Luke!
That's not true. If we use solar or wind power to generate the hydrogen, then it IS pollution free.
----------------------------------
I'd imagine that a couple miles of magnetic linear accelerator might do the trick to get them up to >= mach 2. Wouldn't be practical unless you planned on launching a lot of them though.
"Prefiero morir de pie que vivir siempre arrodillado!"
There's no reason why a (sc)ram jet has to be powered by hydrogen, you could probably power one with kerosene if you wanted. As a matter of fact there was a USAF project a few decades ago to develop a fission powered scram jet ( Project Pluto) for deliverng nuclear warheads. Needless to say it wasn't nearly as environmentally friendly as hydrogen power.
Also, I've seen ram jets built by hobbyists that about the size of a soda can - scram jets don't neccesarily have to be any bigger.
I think scram jets can be developed into a very viable means of providing very fast, cheap, sub-orbital propulsion.
"Prefiero morir de pie que vivir siempre arrodillado!"
i'm so tired of seeing crap on /. and other news sites about .com failures and linux layoffs. the stories are all repetitive pieces about stock prices plummeting back to earth, companies going down in flames, and millions of dollars being wasted.
oh, wait, this is about a rocket of some sort?
-=tonyt=-
Trust me, it would have to go a long way off course to hit anything important, there's not much out there. The british government used to test atomic bombs in the area, and when it was used as a missile testing range in 50's and 60's, they used to close off an area of desert the size of the UK as a "crash zone" for the rockets. Trust me, they could land Mir there and no-one would notice.
When NASP was cancelled it was because the US military plane Aurora was already successfully hypersonic. Janes originally published about this in December 1992 and there is much more evidence now. Do you really believe that the US military would stop all research into scramjets if they didn't have something? db
and let it slam into the ground :-)
Using this to deliver nuclear payloads provides no advantage over the traditional ICBM as far as radioactive emissions goes. If there were enough speed and mass it might make a good kinetic weapon, though. Kinetic weapons have the advantage of being totally non-radioactive. This means that moments after dropping a 2 ton rock on your enemy's capital, you could send troops in from just outside the blast perimeter. The perfect operation.
Pax Digitalia
This should put into perspective the "more environmentally friendly" stuff, since getting to the point where you can start pulling H out of the air, you need to be massively environmentally unfriendly.
Since i couldn't find an email address to send this to on the website with the article, i decided to post it here, since i found out about the article here.
;-) was the X-15 A2. From the late 1950's to the early 1970's, the government and NASA funded the X-Aircraft Project. Perhaps the most famous pilot to come out of this program was Scott Yerger, who flew the X-1, the first aircraft to break the sound barrier.
The article makes the comment that the fastest aircraft known to man was the United States' SR-71 Blackbird, developed during the cold war to spy on the Russians. It flew at speeds around Mach 3.1.
Unfortunately, their research wasn't all that correct. The fastest aircraft known to man, or at least not classified by any government
The X-15 was flown by the best pilots at NASA at that time, including Neil Armstrong who flew the X-15 several times. Since this aircraft was designed for speed, it would be loaded onto the wing of a B-2 Bomber which would carry it into the air, and release it. Upon release, the engines would be fired, and speed would build until fuel ran out. The pilot then glided the plane into a landing.
To add more fuel for faster speeds to the plane, NASA added two external fuel tanks to the plane, one under each wing, that would be jettisoned once empty. It was then named the X-15 A2. The X-15 A2, to this date, is the fastest airplane known to man, reaching speeds as high as Mach 6.7. The plane has been decommissioned, and two models are on display, one at the National Air and Space Museum in Washington DC, and one in the US Air Force Museum in Dayton, Ohio.
Surely it would make more sense to use the output of the rocket motor to funnel high speed gas through this thing, or at least launch it sideways and hope that it gains enough velocity.
This "hope" aspect sounds to me like they don't know whether terminal velocity is gonna be enough or not. It would be funny to watch this thing silently fall into the ocean (or wherever) simply because it never sufficiently overcame its own drag.
On the other hand, if it does ignite, it'll make a nice splash (or crater)
Who was president from the time Reagan left office in 1988 until George Bush Sr. took office in 1989 then?
Slashdot is jumping the shark. I'm just driving the boat.
I hope it doesn't hit New Zealand, 'cause that could push them clear to the bottom of the ocean...
It's the Amiga .sig isn't it?
---
This
This by my *guess*, won't take oxygen out of the atmosphere. Most likely when the jet encounters an altitude without sufficent oxygen, the chemical reaction will stop, not suck the oxygen out of the air.
A good point.
Anotherone is, if it only cost a million, why is it mostly interesting for the military?
Seems like a good time to stop flying Concord?
Question authorities
All right, and where do standard jet engines take THEIR air from? Coach?
God almighty u'd think /. readers would have read the basic canon.
SF writers have been wittering about orbital kinetic weapons since Jules Verne.
Right now the explosive used as fuel does not equal the destructive potential of dropping the rock (or depleted uranium, or whatever u've got lying around thats heavy) from orbit onto peoples heads.
But once we get that space elevator going it could all get more interesting
'There is a Light that never goes out.'
The buzzbombs (Known as the V1 to its friends) used a fuel-air explosion which generated thrust. A set of moving "doors" slammed shut over the intake at the front (like a valve) to push the exhaust out the back and generate thrust.
It was the constant timed explosions that create the "put put put" sound which gave them the name "buzz bomb"
Wandering OT here; guidance was a question of pointing them in the right direction and judging the correct amount of fuel.
When they ran out of fuel they dropped to the ground.
British intelligence which had infiltrated the german spy rings fed the germans false ranging info to make the majority of the things fall short (reporting overshoots as hits and hits as fall-shorts) but thats another story
'There is a Light that never goes out.'
It never made it into orbit but they did launch it off the back of modified 747's and land it...
I think it was realised that it was easier just to explode off the ground (sometimes more delicately than others) than to kinda sorta do it from halfway up.
'There is a Light that never goes out.'
Its called a steam catapult and it flings the planes off the lauch ramp at flight speed, sometimes they need to turn the carrier into the wind to get sufficient speed over the wing.
'There is a Light that never goes out.'
even better it uses 3 totally different propulsion systems
the holy grail of cheap space flight is Single Stage To Orbit (SSTO)
Not a place that becomes a ramjet that becomes a scramjet that becomes a rocket (4 stages now)
With engineering like that you must be English.
'There is a Light that never goes out.'
Now u can do it in 5 hours or teleconference in seconds
Concorde and SR-71 were never going to be able to be mass produced, the AVERAGE air-craft speed is quite a bit quicker now, if you include the reduced refueling times the newer engines have brought about.
'There is a Light that never goes out.'
they are useful for remote areas and as an emissions smokescreen depending on your utilities greenhouse compliance burden.
But as they stand they still require a scad load of fossil/hydro/nuclear power
'There is a Light that never goes out.'
Swedish designed Australian built diesel-electric submarines with a little publicised capability to be turned nuclear in a very short space of time.
The Collins has become the subject of much unfair Australian media coverage largely because they are one of the bigger show's in essentially a small town.
A lot of advanced technical developments that had teething problems exaserpated by the Swedes telling lies about what they knew how to do. The combined teething problems did make them look rather incapable
John Howard:
Conservative Prime Minister of Australia. Like any conservative leader the subject of ridicule by the left, however in Mr. Howard's case much of it is deserved.
'There is a Light that never goes out.'
Modern day planes are huge polluters and loud ta boot. If you had a scramjet passenger glider it could take off with a regular turbine based engine or a scramjet (my understanding of the system is a bit limited). Powering itself with the oxygen it captures along the way. Should anything go wrong with the engines then it would just glide down like the space shuttle does. Of course it could also do a powered landing, but a glide in landing would be extremely quiet. And without very much fuel needed the weight would be a great deal less. Which you could either offset by carrying more (talk about round the world flight), use that displaced weight for better (and often heavier) materials that the plane could be made of, or carry more passengers.
There are possible downsides and I'm not sure if its doable. But wouldn't it be great if it was? The noise problem wouldn't exist and more airports could be built.
Just my two cents
If this actually works, they'll have to figure out how to make an airplane that won't burn up at those speeds!
Wasn't there an issue with the SR-71 that they had to take into the account the expansion of the airplane's skin, such that sitting on the ground, the airplane would leak fuel between the gaps of the non-expanded parts? And that was only at Mach 3...
Wait a second, is this an engineering test or a dot-com business plan?
--
When all you have is a hammer, everything looks like a skull.
He talked quite a bit about how cheap the engine is to make, its very simple, with no moving parts, so it shouldn't be expensive to make.
However, making a cargo area large enough to carry anything of consequence is very expensive.
It is expensive because very few materials hold up very well at such high speeds, and essentially requred engineering a new technology to withstand the extreeme pressure felt at the tip of the craft.
Think about it, this is intended to handle speeds far greater than the mach 7.6 speed the aussies are testing thier engine at.
Spring is here. Don't believe me, look outside!
Are you sure that wasn't a ramjet that your friend built in high school 45 years ago? A Scramjet is a supersonic combustion ramjet, it has to be going faster than Mach 1 to get going. Strapping one to a bicycle or a car won't go fast enough to get it lit.
Actually, the scramjet still needs to run in the atmosphere. It's not a rocket engine and will not work in a vaccum. Actually, NASA has done some tests with one of these on the back of their SR-71.
Someone tell me these engines will enable the takeoff of a 'Personal* Space Plane'?
*I realize they wouldnt be TurboProp Planes like the local Flight Club - but I do mean a 'personal sized' Space Plane
What part of that dont you understand?
And BTW: Although the tech will be the domain of Governments and their military - its only a matter of time and cost before everything ends up in the hands of public citizens....
A friend of mine built and bench-tested a scramjet for a H.S. science fair project 45 years ago. Building a demonstration model is trivial. Making it practical is what the NASA and Boeing engineers get paid for. BTW - they decided long ago that they didn't want hydrogen gas or liquid sitting around airports or any population centers many years ago. The explosion of just a modest amount could turn O'Hare into a moon crater!
You are correct.
Liquifying and storing hydrogen is a bitch. It's so small it tends to escape most types of containment. It does take quite a bit of enegy to compress to a liquid, too.
From my understanding, incomplete burning can also cause nitrogen rich types of gas that deplete the ozone.
My point was that, in a perfect sense, oxygen can be produced and used in a pollution free manner. I know it's not effectient, but possible.
Damned practicallity, anyway!
I'm interested, what's the manner you speak of? Using a turbined power compressor???
Damn, hadn't thought of that.
I wonder how much energy a solar cell would have to produce to over come the energy/pollution ratio of other types of energy production?
Oil you use, and then it's gone. It should have a fairly fixed energy/pollution ratio, but with solar cells, the longer you use them, the ratio gets better -n- better.
Anyone have any idea about this?
Won't the hydrogen go liquid at a high enough pressure? Then you won't have to bleed it back off, you'd just have a container full of compressed liquid hydrogen.
Won't the dripping liquid hydrogen just damn-near instantly boil off?
Haven't had this class for a while, just not quite sure.
What about solar panels? You can run a current through water, from solar panels, and get H and 0. This is a pollution free, allbeit ineffecient, method of getting hydrogen.
I know, it's not practical, but I'm playing devil's advocate and saying that, "Hey, there is a method getting hydrogen that doesn't pollute."
according to the webpage: "Two flights are planned for the late in 2000."
so what happened?
this doesn't sound all that exciting to me, no one has developed anything yet, it's just an experiment for measuring combustion at supersonic speeds. $1M suddenly sounds like a lot.
--
in this age of communication i'm just not getting through
I don't know if you realise this, but cars burn oxygen out of the air!
..the average impact crater size was under one square kilometer.
Zero Sum (don't amount to much). [root@localhost]
Maybe we can bolt the things onto our Collins Class submarines, that way it won't matter if they're louder than CowboyNeal after a night eating Taco Bill. Suggestion for test pilot of the engine; John Howard, he's about to get shafted anyway :-)
Antiquis temporibus, nati tibi similes in rupibus ventosissimis exponebantur ad necem.
...its always good to raise questions, but I think you are oversimplfying quite a bit here. Besides "reflecting sunlight" clouds also serve as a blanket, keeping warmth from escaping back into space. (See: "Venus")
I would have to say that explosives are the most abused technology in all of history.
The followup to that woman jumping from near orbit should be someone jumping from orbit wearing one of these engines. Re-entry ? Bah, Re-entry is for wimps :)
They ARE out to get you simply because They are in it for themselves and they don't care about you.
Where can I buy tickets for this flight?
Australians sure have deep knowledge about PR. I mean, what better way to convince the public of the promises of new technology than by deliberatly blowing it up?
I can see it now:
A: "Lets use one of those scramjet engines."
B: "Is it safe?"
A: "I dunno. But it makes a hell of a crater!"
The marketing illiteracy that stems from hi-tech companies outside the US scares me. It even makes me want to move to the US. God save us all.
Will code a sig generator for food
Oh great. Now any jet with this engine will be the ultimate terrorist target. It'll be like the Hindenburg tragedy all over again: "Oh the humanity, and all the passengers!"
"Ancillary does not mean you get to rule the world." --U.S. Circuit Judge Harry Edwards, speaking to the FCC's lawyer
The other side of the same argument is that you can use solar, wind energy et cetera to turn carbon dioxide, monoxide and water back into petrol (gas?), diesel or whatever. I don't know if effective processes exist to do it, but I know it's possible.
I've seen earlier a good argument that these scramjets are just as capable of producing noxides as your car is, so it seems hydrogen isn't any worse or better at polluting than other fuels; just more suitable for some purposes.
The reason they are using hydrogen is that it is the by far the only fuel that ignites and expands fast enough to be of any use in a scramjet. Fuel choices are limited to those fuels that are capable of combusting and expanding within the nozzle of the engine, as opposed to 10 miles downstream. Any environmental 'features' are secondary.
"Homo sum: humani nil a me alienum puto"
(I am a man: nothing human is alien to me)
My only political goal is to see to it that no political party achieves its goals.
At mach 7.6 it will reach the ground in no time! How will they slow it down? How will it, "stop".
;-)
Kind of frightening, but then if they launch it from Oz it will not matter if it loses control and crashes as Oz is full of the poisonous snakes in the world and full of Convicts too
Assuming mach 7 and the engine being at full speed at 35km altitude (one can dream) then it would only take 15 seconds before it hit the ground.
That thing is gonna make one hell of a thud!
I'm a writer, a poet, a genius, I know it. I don't buy software, I grow it.
NASA is preparing to test a hypersonic scramjet Real Soon Now (tm). The difference is that NASA's scramjet will be propelling itself, not falling from near LEO altitudes after being launched by a rocket.
That's all well and good, but even NASA's test is going to be launched from an in-flight B-52, rather from the ground. Until one of these things is self-propelled from the ground to hypersonic speeds and then lands in a condition suitable for re-use, this technology won't be ready for prime time.
MacOS, Windows, BeOS, GNOME, KDE: they're all just Xerox copies
Scene: [Australian outback, near rocket gantry. White mist sprays from the base of the small rocket standing on the pad.]
Cut to Mission Control
Controller 1: ...launch is green! She's away!
Cut to Gantry [Flames roar from the rocket as it lifts swiftly into the air.]
Cut to Mission Control
Controller 2: We have liftoff! All systems are go.
Controller 1: Telemetry is coming through clear. Altitude 120 kilometers and speed 4000 KMH.
Controller 2: Speed and altitude confirmed by radar track.
Controller 1: The onboard computer will perform the turnaround manoeuver at 350 kilometers.
Close up of computer monitor: [showing picture of a wide parabolic arc with rocket graphic near the top of the arc.]
Controller 2: Manoeuver confirmed by telemetry.
Controller 1: Scramjet engine ready to fire.
Controller 2: 350 kilometer altitude reached. Scramjet ignition should happen any moment...
Controller 1: Negative confirmation on scramjet ignition. Repeat, negative confirmation on scramjet ignition!
Close up of computer monitor: [Showing picture of a narrow parabolic arc, the rocket now near the bottom.]
Close up of computer monitor: [text types across screen]
Close up of computer monitor: This device has been activated beyond the approved zone. This device will now autodestruct.
Controller 2: Telemetry from the payload is offline! Repeat, offline!
Controller 1: [Staring aghast at monitor] It's coming straight down at Sydney!
Controller 2: Damn Motorola GPS-enabled CPU! It killed the Scramjet ignition!
Cut to Sydney Harbor [Fireball blasts upwards behind opera house.]
MacOS, Windows, BeOS, GNOME, KDE: they're all just Xerox copies
Last I checked American dollars were worth more than canadian dollars. So if it was built for 1,000,000 USD, wouldn't the Canadians need to spend more than 765,000 Canadian Dollars?
If this thing only costs $1 million to make, where the hell is all the money going in Engineering sector of our economy?
Now that's probably the best use of $1 Million I've heard of in a long time. If only NASA (or the US Govt in general) could spend money so well...
terradot, growing awareness
>Bob
Wasn't a dog named Laika the first animal (purposefully) launched into orbit?
Marco.
--
Top Most Bizarre/Disturbing Error Messages
I remember seeing an article about scramjets a while back. IIRC, it's based on the engine that gave the "buzzbomb" rockets in WWII their name. With a name like buzzbomb, it has to be loud and annoying.
At least it will fly so fast that you won't hear it for long, and by the time the noise hits, it will be long gone.
That's assuming you still have eardrums left after a sonic boom at mach 7. And forget about suing for damages. At that speed, the lawyers will never catch them.
(Do not sign anything.) -- Fell, Planescape: Torment
Compared to the chronically delayed NASA hyper-x, the hyshot delay is pretty small.
It is interesting to note that this group at the University of Queensland, Brisbane, Australia were the first to demonstrate a thrust-producing scramjet in a wind tunnel. Cheers.
V1- pulse jet, like a ram jet
V2- liquid oxygen and alcohol, a real rocket.
One of my instructors is a configuration manager at the company the government has hired to perform the measurements of the US version to be tested later this year. Apparently the plane os launched from a rocket which is launched from a modified jet. The jet sreams to the edge of space and at some point should disintegrate. The study is to find out just how fast and how hard the scramjet can be pushed, measure stress and all the other good stuff to know. Sounds fun to me.
There is no guarantee that the content has been read or understood.
If this engine finally brings the Mach 6 flight we've all been waiting for (and at one point supposed to be available by 1990 or so), then why aren't we investing 100 billion $$$ in this idea, instead of the ISS/Alpha/whatever space station? Let's face it, hypersonic flight on Earth is a lot more useful and practical than anything the airborne guinea pigs could ever come up with!
Meanwhile, we're still sitting around where the fastest military jet (SR-71, mostly built in the early 60's) was decommissioned recently and the fastest commercial jet (Concorde, also vintage 60's design) just went down in a flaming wreck and may never fly again. Pathetic!
Yes, the problems are obvious. From what I gather, current commercial aircraft has gone along the trends of low-speed (subsonic) flight mainly because a) it's proven and relatively very reliable, b) it's the only thing most people can afford and c) no sonic boom to worry about. You can possibly fix 66.7% of the problem, but you'll have to get creative with the last one. Mass produce the stuff, go through the requisite crash tests, and make it happen?
> You'll likely to see this technology developed first for militaries then later adapted for civilian use.
Most probably it already is in use. Do a Google search on "aurora scramjet".
- Hurga
For the History Challenged, Reagan left office in 1988...
"Make it ten--I am only a poor corrupt official."
--Captain Louis Renault (Claude Rains), Casablanca
Climatology is only really beginning as a science, so we're (me especially) all just talking out of our asses, right? It would be nice if we could predict the effects of X, Y, or Z on the planet, and move right along w/ the climate engineering and keep the earth habitable for the next x-thousand years, but that isn't something I expect to see in my lifetime. It would be nice to see those spaceplanes in my lifetime though...
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IANASRP- I am not a self-referential phrase
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IANASRP- I am not a self-referential phrase
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email: proprietary becomes free, org to com
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IANASRP- I am not a self-referential phrase
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IANASRP- I am not a self-referential phrase
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email: proprietary becomes free, org to com
Good Point, I did not think of that. I was thinking of the smallness of the motor and the lack of something hitting it. Now all we need to use is an asteroid (very small) ONEPOINT
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Haven't they heard about all the troubles NASA has had trying to develop this technology?
Maybe in a vacuum it could hit Mach-20, but there's this stuff that's all around us. It's called air. You need to take into account the 'drag' factor. Objects do not free fall with an indefinite acceleration. At some point the gravitational force and the drag force become equal and the object falls with NO acceleration, just constant velocity.
Oh yeah, it also requires, A LOT of power to push something through a medium like air to Mach-20. I don't think a scramjet could do it.
As I understand it, water vapour emissions can be quite damaging at normal cruising altitudes.
We find H20 emissions acceptable because water vapour is so common - at our own altitude. But remember, for example, ozone is healthy at high altitudes but is bad bad bad at ground level.
Water vapour emitted from aircraft is thought to be a serious contributor to the greenhouse effect - not because it is a particularly damaging gas, but because it is released at the altitude where it can have maximum effect.
Dean Kamen's new invention, code named Ginger, has been modified. This scooter-like device was designed to run on a Stirling engine, but new reports by Steve Jobs and Jeff Bezos say it will run on a hydrogen powered jet running at Mach 7.6...
-- Nerds on toast in the new millenium
No, there's no conspiracy theory. We all know the second prototype is in a barn in Saskactewan.
www.lucernesys.comHorizon: Calendar-based personal finance
Sorry - I guess I should have posted this interesting detail as well. A quote from here states:
.
The Mark 2 production version of the arrow, powered with two Avro Canada Iroquois turbo jet engines, would have been capable of achieving Mach 2 with full military load.
Unfortunately only the prototype was developed, however it did have a successful test flight before the program (and everything related to it) was destroyed. Sounds pretty interesting, considering that flight occurred in 1958!
You can accomplish anything you set your mind to. The impossible just takes a little longer.
I suppose it's true. We are patriotic in a somewhat subdued way.
:)
However we do notice that NASA (and likely the media) is pretty careful to only release photographs which include the arm in a position where you cannot see the Canadian flag painted on it. Perhaps that's why we Canadians seem so eager to remind you
Good point, though. Touché on your part.
You can accomplish anything you set your mind to. The impossible just takes a little longer.
---------------------
1. Jet engines, including scramjets, work by "squeeze bang blow" the bang is where you add the fuel. In this case the squeeze is supplied by the velocity of the aircraft. The "blow" is simply due to volumetric expansion of the heated gas creating thrust as the air exits the back of the engine. Fuel creates heat, heat breaks the nitrogen tripple bound, the single nirtrogen atom finds an oxegen atom and pollution is created. Hydrogen is not necessarily a pollution free fuel. In a fuel cell yes, it could be...theoretically (it isn't pollution free today) (how much pollution would be generated creating the hydrogen... that is a different story). In a scramjet or other engine... plenty of pollution. 2. Scram jets have been around a while. Have you ever attended a Combustion symposium? Its a big conference held every four years on combustion; at every one for decades there have been quite a few papers on scramjets. The problem isn't getting one to work, its the HUGE spikes and drops in acceleration. Acceleration spikes from +150G's to -50G's and back again. Anyone want to guess what this does to a passenger? Anyone want to guess what this does to any cargo that isn't a solid chunk of metal?
Glad to help debunk that lose use of terminology. The SR-71 propulsion system really contains two Pratt and Whitney J-58 turbojet engines. Now, keep in mind several things: first of all, the flow at the jet engine face must be subsonic. To date, no operational gas turbine engine has supersonic axial flow through it. So all of today's gas-turbine engine'd supersonic planes have an intake system that sets up a shock system to make the flow following the last shock (a "normal" shock) subsonic. This is the flow the engine face sees.
The SR-71 incorporates what's called a mixed-compression inlet, that is the _external_ big (movable) cones do some of the compression, setting up a conical shock wave, and then an _internal_ "shock train" (several small "linked" shock waves) inside the inlet lip do the rest of the slowing down and inlet flow compression to subsonic. Now at full speed, the SR-71 is operating with the J-58s in full afterburner. The "ramjet" designation comes from two details.
One is that at full speed, a good portion of the air that passes through the inlet then gets ducted directly to the exhaust nozzle -- but this air has already contributed to the thrust because it is part of the high-pressure stream pushing on the back of the inlet cone (higher-pressure against aft-facing area is thrust, boys and girls).
The other detail is that the J-58 engines have big tubes that at high Mach, bypass a lot of flow past the high-pressure compressor stages and directly to the afterburner. This bypassed air doesn't see a turbine, so it's "like" a ramjet in that sense. But because the majority of the flow at least passes through the gas turbine engine's compressor and afterburner, it's not a "true" ramjet.
You are correct regarding subsonic operation of ramjets. What differentiates the two is that scramjets have supersonic flow all the way through the engine flowpath, whereas scramjets turn their flow subsonic before combusting it. Both engines use the exact same principle for air compression -- setting up a shockwave system that the air passes through. As the air passes through the shock wave, it slows down and its static pressure goes up. The ramjet must have the flow following the last shock be subsonic, whereas in the scram it is supersonic. However, the air gets slowed down in both cases (if it didn't, there would be no compression).
:)
While an engine that could do ram/scram certainly would have a larger operational flight Mach number range, it wouldn't be able to get off the ground on its own (i.e. no static or subsonic thrust). Research has indeed been done on combined gas-turbine ("conventional jet")/(sc)ramjets (known as "combined-cycle" engines), and that kind of beast could potentially have the the full envelope capability. Also, don't confuse the SR-71's so-called "turboramjet" as being a combined-cycle engine. It doesn't have a true ramjet-type flowpath, and the compressor would start to melt if the flight speed reached "true" high-speed ram/scram speeds.
All this kind of talk, though, is sort of pie-in-the-sky and ignores the fact we've still not yet demonstrated a free-flight scramjet-powered vehicle. That's what NASA's Hyper-X project is supposed to address. You can get more info on Hyper-X via http://www.dfrc.nasa.gov/
BTW, as you might have guessed, IAAE (I am an Aerospace Engineer)...
Isn't that what Michael Knight turned KITT's engine into in that episode of Knight Rider when they got stuck in the dessert?
--
A buddhist walks up to a hot dog stand and says ``Make me one with everything.''
IANAAE (I Am Not An Aerospace Engineer) but IIRC (If I Recall Correctly), a huge proportion of the fuel used to put a shuttle into orbit is used in the first mile or so, getting up to the speed of sound.
/. article).
This is why NASA is working on a launch system that runs on an inclined rail using electromagnets. (from a past
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Ramjets and Scramjets were used chiefly in surface to air interceptor missiles of the 1960's and 1970's. For taking out high-altitude bombers and supersonic attack planes.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
They're more than acronyms now, they're web cliches. Had to use em. But didn't want to risk the inevitable 30 or so postings afterwards asking "what does IANACN stand for?"
I Am Not A Clueless Newbie.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
It follows that ultra-light rockets that can achieve orbit would be practical, using this kind of technology.
Second, it -ALSO- follows that giant rockets, capable of putting entire large-scale constructions into orbit, would be practical, as it would be within the sorts of costs you expect for modern rockets.
By implication, if the Oz engine works, you could start seeing groups of High Schools (with a bit of sponsorship) lobbing entire space-stations into orbit, rendering the ISS completely worthless.
(Which, to be honest, is an accurate assessment anyway.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Unfortunately, this method produces gas-state hydrogen. The liquifying process requires energy also. I know a slick way to do this with water power, but it's not very efficient...
-- Jeff Paulsen
I haven't tried this myself, but here goes. It should work for liquid air (mostly nitrogen), but the principle should hold for hydrogen as well. Take a pressure-safe vessel and put it in the creek. Take a paddle wheel and put it in the creek. Use the wheel to compress your gas-state hydrogen into the pressure vessel. This heats the hydrogen, but the heat is lost into the running water. When the vessel is full of high-pressure room temperature hydrogen, bleed the hydrogen out through a small valve. Hydrogen expands, cooling as it does. Liquid hydrogen then drips from your valve, with extensive loss to the air.
Pretty crappy, eh? But for liquid air, the loss doesn't matter much, and all you had to do was go down to the creek.
Feel free to tell me why this won't work, if anybody knows a reason.
-- Jeff Paulsen
Ok, is it me or does this planned test sound like an Urban Legend in the making.
-The JungleBoy
--
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might be running loose in your pants."
"You never know when some crazed rodent with cold feet might be running loose in your pants."
-Calvin
Hydrogen can be obtained from non-polluting sources of power such as solar. But it would seem that a hydrogen-burning engine is going to produce some oxides of nitrogen, as long as you suck an oxygen-nitrogen mixture (air, of course) into the engine.
There was a Canadian comedian (I forget who) I heard on the "This American Life" radio program saying that Canadians cannot let a comment about space flight pass by without saying "Canadian-made robotic arm! Canadian-made robotic arm! We made that arm!"
And what do you think happens to that oxygen it takes out of the air?
Answer: it combines with the hydrogen to become water vapor, which then falls on the ground as rain, where it sustains plants, which are busily converting carbon dioxide into oxygen.
As for "hundreds of rockets smashing through the stratosphere a day", compare the cross-sectional area of a rocket with the "surface area" of the stratosphere, say "gosh, that's a tiny ratio" and then stop to think how much worse all the petroleum fuels burned by airplanes are for the atmosphere.
Hell, next you'll be worrying about the fact that every launch slows the rotation of the Earth.
-
This is somewhat old news. Now call me a conspiracy theorist, but I honestly believe the US govt has had atleast one of these types of aircraft for quite some time now.
In the 90's, Reagan started the Aurora Project which was to create a hyper-sonic plane that could go from NYC to Tokyo in under 2 hours. The engines were scram jets.
The project was never really heard of since then, but oodles of initial money was dumped into it. Also, the US' fastest airplane, the SR-71 has since been retired with no replacement (some say that satelites make high/fast flying planes obsolete). IMHO I think we have a couple of these jets being used in our military.
I'm pretty sure I've got my facts straight on this. Anyone else heard of this?
"Woomera is right in the middle of nowhere so it's a bit hard to hit anything."
...
"Now it's used as holding area for illegal immigrants..."
Sooo... it's a bit hard to hit anything but illegal immigrants? Check.
Kevin Fox
--
Kevin Fox
Laiks was the first cosmonaut. :-)
Science, like Nature, must also be tamed, with a view turned towards its preservation.
Ramjets may be; scramjets I doubt, as there is no self-sustaining, thrust-producing scramjet in operations, AFAIK. Little problem with trying to combust air while it's travelling higher than the speed of sound (and thus pressure waves, and thus flames) of the medium combusting.
Solar cells are a type of semiconductor. And we all know how clean and pollution free the semiconductor manufacturing industry is. Pollution free, hah!
Ryan
The X-15 wasn't a jet. It was a rocket. Air launched from a B-52. They have one at the National Air & Space Museum. Seriously cool looking.
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Yes. You can burn hydrogeon fairly easily on the ground and despite atmospheric conditions, the speed at which the aircraft is travelling actually creates enourmous pressures (and ammounts of O2). The problem with scramjets is that like their cousins ramjets, they must be taken to very high speeds before the engines can operate. Those speeds are estimated at around Mach 2 to Mach 4. This is because, the compression is achieved not with a turbine (as in a traditional jet) but with the velocity of the incoming air.
Someone you trust is one of us.
One thing you need to add: Things like Ozone and nitrogen oxydes aren't created by the fuel itself, but by the heat involved in the combustion. It's likely that a Hydrogen engine will still produce this kind of pollution.
Opus: the Swiss army knife of audio codec
Stupid sexy Flanders.
Because of the slightly different climate, Canadians have a tendancy to take the probability of environmental extremes more seriously. +40C~-40C is supposedly considered US Mil Spec (104F ~ -40F). In Canada, it's considered outdoor equipment. I can exceed those exremes in one year driving around Alberta. Most years I can get +30~-40 just planting it in my backyard in Edmonton.
A friend ofmine has a story of some oilpatch equipment that froze up while stil inside of it's rated spec (rated to -45C; froze at -37C). He called down to the Texas company that supplied it to complain. The answer:
----In any event, there isn't a whole lot of conspiracy theory around the Avrow. The generally accepted theory is that the US needed many of those hot engineers for the Apollo project. That's where many of them went when the Arrow was tanked.
You didn't think that the States could get all the way to the moon without foreign help, did you?
As to the Avro enginering data being destroyed, it makes complete sense to me. The system was capable of doing stuff that the US was either incapable of, or unwilling to acknowledge being capable of. With most of the engineers going over to NASA associated work, the project was going to be, at best, mothballed for a long time. The last thing that you want is to have all this engineering data stacked in a warehouse somewhere just waiting for a Soviet Spy to cart it off to the Embassy. Far better to just trash the existing data, and rebuild from scratch later when/if you decide to do it again. Besides -- by the time they'd get around to restarting the project available technology could be expected to have advanced beyond whatever miracles they'd produced back then.
Pretty much the same thing was done with the Saturn 5 engines when NASA decided to go to the Space Shuttle. Although some people feel that it was done to prevent the ability to go back to non-reusable craft, I think that the security explanation is quite applicable here as well.
--
Free Software: Like love, it grows best when given away.
And hydrogen is a pain in the ass. It has a higher specific impulse (thrust per mass of fuel) than any other fuel. That's why NASA is addicted to it. But it's density impulse (thrust per volume) sucks. Plus it's a hard cryogen. So you have to have a BIG, well insulated tank. That translates into major weight and major drag. This is OK on the ground, but it's really not such a great aerospace fuel. NASA insists on using it, as far as I can tell, mostly for reasons having to do with internal politics and organizational culture. (The Russians use kerosene or alcohol, which don't have as good a specific impulse but have a much, much better density impulse.)
"Research is what I am doing when I don't know what I am doing." -- Wernher von Braun
Depending on how high up the rocket sends it, it could easily, with an apogee of, oh, say, 1.6 million feet, attain a speed at reentry (300000 feet, or about 100 km) of 24,400 feet/second, well over mach 20-something (I just ran my code for those numbers for something completely different, how coincidental!).
Then, of course, it will heat up very rapidly and ablate. The point is, speed is not a problem, but materials may be.
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You're right. As the object falls into the atmosphere (300 kft is above the sensible atmosphere, and right on 'the edge'), the dynamic pressure increases and drag goes with it, slowing the vehicle down until it 1) reaches terminal velocity, or 2) slams into the ground. What I am flying slammed into the ground at 20000 fps. I looked at the picture of the hyshot on the webpage and it reaches apogee at just over a million feet. This means it might have a max v of about 18000 fps or so. Then it starts slowing down. When it hits the desired speed (I am sure it isn't as low-drag, or high-beta to be pedantic), it flicks on the jets and uses that to basically overcome the effects of drag.
They are claiming a sustainable velocity of Mach 7.6 or so, so you are correct. It would be prohibitive to expect Mach 20, but the fact is, it may pass through that velocity. The higher they go, the harder they fall, and velocity in a vacuum is only a function of potential, that is v= const* sqrt(h), h being height at apogee.
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big deal
I am become Troll, destroyer of threads
As a canadian, that was my first thought...
I am become Troll, destroyer of threads
I remember an old story illustrating the differance a 50 or 100 year gap in technology makes. It was based on the idea of someone from 1920 trying to cope with a jet engine from 1970 drone with semi conductors, etc. interesting stuff.
just goes to show you what progress has been made
"It is a greater offense to steal men's labor, than their clothes"
Dude, the first rule of Flight Club is: Never talk about Flight Club! You also forgot the second rule of Flight Club, which is: Never talk about Flight Club.
A couple of people have mentioned the Arrow, presumably because this article appeared in a Canadian publication. However, it should be noted that nowhere does it mention any Canadian involvement in this scramjet research.
Also, I think comparisons with the Arrow are not very valid.
The Arrow was not a research project on new technology, it was an engineering project to produce a working fighter incerceptor that can enter active service.
It was a military vehicle, which meant that the market for it was relatively small. Furthermore, the Canadian requirements on the aircraft were so specialized that nobody else in the world was interested in such a beast.
On the other hand, the market for a working scramjet vehicle would probably be huge.
I'm not going to start speculating why the Arrow project was nixed, because that would probably ruffle a lot of Canadian feathers and start a flame war (it's probably Canada's biggest conspiracy theory).
Personally, I don't find it fishy that they cancelled the project; I do find it fishy that everything related to the project was destroyed.
--
Accountability on the heads of the powerful.
Power in the hands of the accountable.
Would it be possible to strap a couple ScramJet engines to what is essentially a 'large-ish' and appropriately desgined 'airplane' and fire up a couple solid fuel rockets to propel the bastard into space?
Someone tell me these engines will enable the takeoff of a 'Personal* Space Plane'?
*I realize they wouldnt be TurboProp Planes like the local Flight Club - but I do mean a 'personal sized' Space Plane....
How does MACH7.6 compare with the the speed necessary to escape the atmosphere and head off into space? Obviously I realize the mass of the vehicle is relevant. What Im getting at is would it be possible that this technology could lead to what Im describing?
Pollution free? Maybe air pollution free, but I doubt that it is noise pollution free! At least it will fly so fast that you won't hear it for long, and by the time the noise hits, it will be long gone.
Keeping
I think this is an excerpt from the Southwest Airlines business model.
The X-15 plane (scroll down the page for program history), which flew for the first time in 1959, exceeded Mach 6, and flew over 100,000 ft.
The project was eventually cancelled, after a combination of spectacular crashes, exceedingly high costs, and the success of NASA's programs.
It is interesting that the X-plane pilots viewed themselves as the true masters of high-altitude and space flight. In their opinion, they were in control of their missions from start to finish, unlike the Mercury astronauts, who were simply strapped down on top of an explosive bottlerocket. Indeed, the first astronaut was a chimp!
Bob
Science, like Nature, must also be tamed, with a view turned towards its preservation.
Little thing, but Ramjets definitely don't produce subsonic thrust. No moving parts, so without a strong compressed air input there's not a whole lot they can do... They're restricted to Mach 2 ish and above, too.
I was trying to find something on Google to back this up - hit Roger Ramjet instead :) Try http://www.britannica.com/bcom/eb/article/6/0,5716 ,64186+1+62599,00.html?kw=ramjet instead.
Greg
(Inside a nuclear plant)
Aaaarrrggh! Run! The canary has mutated!
It's a good thing we're dumping all that CO2, then, so that the plants can get carbon to build roots to gather H2O which they can convert (together with the CO2) into hydrocarbons and free oxygen.
Save the environment! Burn coal today!
---
Did you notice the careful wording of the SR-71 description?
"The fastest known aircraft was the U.S. SR-71 Blackbird..."
Liquid Hydrogen does not occur naturally here on earth. The most natural state of hydrogen is as a component of water. And when it's burned it turns back to water. Even with a 100% efficient process it takes as much or more energy to create liquid hydrogen as the liquid hydrogen itself has the potential to create. Therefore it's not polution free, the polution is simply pushed off to some other source that generates the hydrogen, such as a coal, gas, or nuclear power plant.
So I wish I could stop hearing how burning liquid hydrogen is our savior as unlimited pollution free energy.
-- Greg
Slashdot, would a spell-checker for posting be too much to ask? It's not rocket science!
They also claim that they have set the world speed record for a chamaign cork (40 km/s) here (bottom)
If Godzilla did not exist, man would have had to create him.
It will.
Really.
There is a lot of it, surely. But when you get into the stratospheric levels there are delicate layers up there. The ozone layer is not just a simple 2 atom thick layer of ozone, there are support layers of other gases that help to keep it stable.
I agree, this technology is vastly superior to using fossil fuels for transportation purposes.
I simply hope that they work out the bugs and take the climactic effects into account, so the cure isn't worse than the disease.
Yes we have rockets all the time, but this is a question of scale. We do not have hundreds of rockets smashing through the stratosphere a day.
Goat sex free since 2001
One example of Canadian engineering abilities might be found in some of the sites regarding the ill-fated Avro Arrow, like here and here. Some of the things achieved with this experimental craft have never been duplicated, and unfortunately the project was only destroyed due to political reasons. It could be said that while the U.S. does have great research abilities, in some areas the U.S. can learn from their Northern neighbours. After all, even NASA is still using the Canadian-made robotic arm on the space shuttle.
You can accomplish anything you set your mind to. The impossible just takes a little longer.
On top of that, the article is so short on facts (not even any links to more information in the article body - don't these nitwits understand what hypertext is about?) that it's hardly worth reading. News for nerds? I think not.
--
Knowledge is power
Power corrupts
Study hard
Time is Nature's way of keeping everything from happening at once... the bitch.
It means that the combustion occurs above mach 1. A normal ramjet is quite capable of operation above mach 1. However, the incoming air is slowed down and pressurized before combustion. In a scramjet, the air is still moving at supersonic speeds relative to the combustion chamber and fuel injectors. I've seen trying to keep a hydrogen/gasoline/whatever flame alive in those conditions (at the qantities of fuel burned by standard jet engines and more) compared to keeping a candle lit in a hurricane. It's difficult. No, REALLY. The benefit of a scramjet is that it can operate at REALLY high speeds. A ramjet loses too much energy slowing the air down to work above about mach 3-5. The concept is *similar* but fundamentally different.
I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
Conventional turbine engines can of course be used, but they don't really like getting all the way up into the scramjet operating range. Thus, there has been a lot of research into engines that can work both as ramjets (subsonic combustion) and scramjets (supersonic combustion). Whereas they would still need to be moving around Mach 1 before they can start operating, it means conventional engines would be used for less of the flight, OR that the use of rocket combustion (bring your own oxygen) for the initial part of the flight without a serious weight problem. After all, the whole point with this whole thing is to avoid the rocket weight problem of having to bring your own oxidizer and just use the O2 in the air. Since for an H2-fuelled engine the oxygen is 8/9 of the weight, the advantage is obvious.
(Did I mention that I really hate that Slashdot don't let you use <SUB> and <SUP>?!?)
Call me crazy (go ahead, do it) but I see a rocket going up really fast, turning over, coming down really fast in order to build up the speed to go down even faster (2 kilometers per second) and then it hits the ground (or whatever). Isn't anyone concerned about a system that has no uplink at all, using only internal instruments for navigation, with this kind of power? There's no way to turn it off once the launch pad umbilical is cut, and even if things go right, 2km/sec is faster than anything else I've ever seen hit the ground. Even the terminal velocity of meteors is often slower, because they aren't falling and pushing at the same time.
I'm worried, but I wanna see...
Kevin Fox
--
Kevin Fox
"Thank God it landed in that smoking crater!"
"Prefiero morir de pie que vivir siempre arrodillado!"
--