NASA Provides Results Of Scramjet Test

Guinnessy writes "Last March, NASA carried out the world's first test flight of a scramjet-powered aircraft. The Industrial Physicist has the latest results from this test. According to the article scramjet-powered missiles and aircraft could be in mass production as early as 2010. This piece is also a good introduction for those unfamilar with scramjet technology."

Comments

Scramjet powered missiles/aircraft?!

[JoeShmoe950]

I want a scramjet powered heatsink to OC my CPU (ok, it make it hotter, but anyway...)

Great news!

[AKAImBatman]

One thing that has often concerned me is the matter of lift from the wings/lifting body. Obviously this design should be able to go into orbit with a relatively minor assist from rocket engines. However, how much lift does it actually get? Is it possible to build a craft that can use wing lift all the way up to LEO? If so, could it then be possible to obtain a flight envelope on the way back down?

The primary reason why I've concerned myself with this, is that the Space Shuttle literally "falls" out of orbit in a very steep dive. The idea is to re-enter somewhere over the Pacific and shed enough speed to land just before the Atlantic. Obviously, it was important the normal flight operations didn't overfly the USSR. The problem with this sort of profile is that the Shuttle takes on a tremendous heat load from the aero-braking. Yet there's nothing really inherent in the atmosphere that says the the Shuttle MUST take on that load.

To get to the point, would it be possible to return in a glide or powered flight without the requirement of a heat shield? i.e. Could a vehicle obtain a thin-atmosphere flight envelope and reduce its speed at a more gradual rate? Perhaps even to the point where no shielding is required?

Any aerospace engineers in the know want to comment?

Re:Great news!

[AeroNate]

Any aerospace engineers in the know want to comment?

Well, I am not an expert in reentry, but I'll take a crack at your question. I think the important thing is not maximum heating, but rather some integral of heating over time. If the shuttle or other vehicle entered more gradually, it may be that it would actually reach a higher temperature because it would have more time to soak up the heat from the plasma around it. No matter how well you insulate something, eventually it has to reach practically the same temperature as its surroundings. You hope to get on the ground long before that happens.

Wings are heavy and delicate, and it would be hard to imagine that they could be large enough to significantly lift the craft at high altitude and lower speed and still survive the heating. (The heavier the wings are, the more kinetic energy you need to dissipate to slow down--and the more heating you get.) IMHO wings are a dumb thing to carry into space with you. Lifting bodies are better.

Re:Great news!

[Phanatic1a]

Is it possible to build a craft that can use wing lift all the way up to LEO?

Maybe.

In a real gas, aerodynamic lift is always accompanied by aerodynamic drag, and the ratio of the two is not dependent upon density or pressure or altitude. Until the point at which you actually achieve orbit, if you are relying upon aerodynamic lift to keep you in the sky, there's a certain amount of drag you have to overcome just to keep accelerating, and you can't make that problem go away by playing with the altitude.

The absolute best hypersonic lifting body designs anyone's been able to come up with, even theoretically on paper, have lift:drag ratios on the order of 10:1, so you need a thrust:weight ratio of at least .1:1 to keep accelerating.

Re:Great news!

[Hakubi_Washu]

Hm,
I'm no expert either, but I would tend to think that the re-entry problem is not height, but the speed required to stay in orbit. In order to return to earth you hve to reduce speed pretty heavily (The reason SpaceShipOne didn't "reach orbit" was that it can't ever reach the necessary speed in the first place). If you don't do this "fast" enough you'll not reach earth surface, but continue to orbit, albeit way more eccentric. It is possible to land in this way, a lot of mars flight plans include this multiple aerobraking/atmosphere dipping, but it takes a) a lot more time, as your orbit takes you pretty far outwards between the "dips" and b) it is way more risky as your calculations have to be very precise (Otherwise... You know what flat stones can do on water? :-)
As I said, I'm merely a /.-reading geek, but I think this is pretty much what the problem looks like...

Re:Great news!

[Planetes]

However, how much lift does it actually get? Is it possible to build a craft that can use wing lift all the way up to LEO? If so, could it then be possible to obtain a flight envelope on the way back down?


This depends entirely in how you define leo. In order to reach what is generally considered space (100km+) you will be outside 99% of the atmosphere. This means that the atmospheric density is extremely low. So low that the normal rules of fluid mechanics are invalid and you have to treat air as a rarified gas. This is statistics based rather than standard calculus based. The extremely low density effectively means that lift from the wings/lifting body is essentially zero unless you have an extremely large surface area. In fact, at this point, drag and the erosion from atomic oxygen and free hydrogen are much more prevalent than the force of lift. As a result, once you reach this point lift is essentially zero although the engines would continually accelerate you to the necessary orbital velocity.

In other words, lift would be dependent on your surface area of the wings. This will get you to the top of the atmosphere. At which point, you have to use pure thrust to reach orbit. In addition, once you reach a certain point the O2 levels drop to the point where a scramjet is useless and you need to use conventional rockets.

Orbit is more a function of speed than a function of lift or drag. ISS uses reboosts periodically to compensate for the fact that LEO actually exists within the upper atmosphere and it's subject to a drag force.

Re:Great news!

[jafac]

Orbit is more a function of speed than a function of lift or drag.

Exactly right.

One coule achieve orbit at "sea level" so long as one was going fast enough, could somehow maintaint that speed given the aerodynamic drag at that altitude, and encountered no terrain obstacles.

The hope of the Scramjet is;
Obtain enough velocity while still within the atmosphere to attain orbital velocity, while overcoming drag via engine thrust. Of course, the vehicle will eventually run out of fuel, so the next aim is;
At this altitude, obtain SURPLUS velocity, which can be used to gain altitude (no longer via aerodynamic lift, but through sheer newtonian momentum). As altitude is increased, there will be a point where there's not enough air to run the engine, yet there's still enough air to create drag. That drag, plus speed lost to attain altitude, will slow the vehicle down. If the engine produced enough surplus velocity, then, in theory, it could reach what we normally consider to be LEO (about 200 miles?). It's even theoretically possible to reach higher orbits, or even escape Earth's gravity altogether - if we can find a material that can stand the thermal loading during the attainment of this surplus velocity, and if we can carry enough fuel with us to burn. But outside of the realm of theory lie the cold hard facts that we don't have materials like that, so we'll probably just use rockets to attain higher altitudes.

In which case, it seems to make more sense to use the scramjet on a BOOST vehicle, and stick to a rocket upper-stage to propel your orbiter or payload. The scramjet booster should be recoverable, of course. So it's looking more and more like the future model of space flight is something like what Scaled Composites came up with:

A smaller Orbiter or Payload-type vehicle, rocket propelled, piggybacked on a larger booster vehicle. Probably also piggybacked on an even larger carrier.
(say - a modified C-5, carrying a large booster to an altitude of say, like 60,000 feet or so (what's the C-5's service ceiling?) - Drop the vehicle, that uses an initial rocket boost, or perhaps turbofans, to get up to Mach 2-3, a Scramjet for mach 3-15 or so, then at a given altitude, release an upper-stage for orbital insertion and maneuvering. The Booster stage returns for recovery, as well as the carrier. The upper-stage vehicle doesn't really need to be reusable. Unless it's manned. The most expensive hardware would probably be the Booster vehicle. If the upper stage is manned, well, there's a lot of very expensive avionics and life-support stuff you'd want to recover and re-use. But we're no longer talking about something the size of the Shuttle. Not even the combined Booster/Upper-stage. I guess a C-5 could probably carry something that large, but since the Carrier is doing the bulk of the heavy-lifting that would otherwise have been done by the Shuttle's main engines and external tank, the Carrier shaves a bunch of mass off the Booster/upper-stage, which leaves a lot more capacity for payload.

Re:Great news!

[mlyle]

The Soviets did it on Zond 6 (part of the Lunar L1 program), and it was heavily studied for Apollo and subsequent vehicles. Peak heating is lower than other entry methods, but only slightly, and the degree of precision required for the same ultimate landing position accuracy is much higher.

From http://www.space.edu/projects/book/chapter20.html

On November 6, 1968 a Proton rocket launched Zond 6 to within 2420 km of the Moon's surface. Cameras aboard photographed the Earth rising over the bleak lunar terrain; however, on the way back a gasket failed which would have killed any cosmonauts on board. Zond 6 performed a complex skip maneuver, decelerating to 7.6 km/sec over India then skipping back into space and landing in the Soviet Union. The parachute failed during landing and, once again, any human occupants would have perished. After this disaster, any thoughts of sending a cosmonaut to the Moon before January 1969 faded as Apollo 8 accomplished its historic lunar mission. There were three more Zond flights after Zond 6; a potential Zond failed on the 20th of January 1969 when its Proton booster failed. On August 8, 1969 after the successful Apollo 11, Zond 7 successfully orbited the Moon and returned. The last flight, Zond 8, was flown a little more than a year later successfully around the Moon, but landed in the Indian Ocean rather than back in Russia.

Re:Great news!

[AeroNate]

Yeah, thermodynamically irreversible processes like friction and shockwaves turn kinetic energy into thermal energy, and in this case the atmosphere is heated to a plasma by the vehicle's motion relative to the atmosphere. (Mainly at the leading edges where the shock waves are, I think) So, you can attribute it to friction if you like. But the interaction between the vehicle and the gas/plasma is the heating mechanism. Once the atmosphere is heated at the leading edge, it flows back past the rest of the vehicle. I believe there is a thin layer of relatively cool gas in between the tiles and the hottest plasma. (It has been cooled by giving up some of its heat to the cooler surface of the vehicle. When there is a disruption of the flow (like when tiles are damaged on a shuttle) the resulting increase in turbulence can increase the transport of heat through this cooler layer and cause problems. If you could slow down higher up, then, yes, that would be good, but it is hard to do without causing heating because you have to push on the atmosphere somehow in order to do it. You could use an engine burn, of course, but that is very expensive and that means that you had to take extra fuel into orbit with you, which means that you could have had a bigger useful payload instead. I read somebody's explanation of why a winged reentry is inferior to a capsule and heat shield, and I bought his arguement, but I cannot remember it I'm afraid.

just what we need

[SuperBanana]

The 2003 engine has the potential to power future missiles, aircraft, and access-to-space vehicles. Last year, the Defense Advanced Research Projects Agency, U.S. Navy, Boeing, Aerojet, and Johns Hopkins University also ground-tested a scramjet engine, which was constructed primarily from nickel alloys, powered by JP10 jet fuel, and intended exclusively for hypersonic missiles.

Great. So now we'll have missiles that can do mach 15. It's being billed for aircraft as well, but nobody seems to have addressed issues of, gee, say, it only being useful at incredible altitudes. Nevermind that the airline industry is crumbling requiring massive bailouts from the Feds, and the only supersonic aircraft to date to do commercial passenger flights was never profitable in almost 40 years of operation.

The most influential of these efforts was NASA's National Aerospace Plane (NASP) program, established in 1986 to develop a vehicle with speed greater than Mach 15 and horizontal takeoff and landing capabilities. The program ended in 1993,

"The program ended"? What a polite way of saying "we failed. But along the way we spent almost 10 years and probably billions on some futuristic space plane with no real purpose."

I'm sick of NASA justifying themselves as an organization for exploration and science- when they're instead spending most of their time (and my money) on weapons platform research and lining defense contractor pockets. We haven't managed to do anything for millions of Americans with no health insurance , our kids are dumb as bricks because their schools are cutting programs and staff, and our police/fire/ems departments are laying off staff left and right from budget cuts...but hey, we've got a plane that can do mach 15 at 100,000 feet! Sweet!

Re:just what we need

[SuperBanana]

The problem is that killing NASA won't solve those problems you state or remotely fund a fix on any of them, unless you want an emotional band-aid.

I see. So we should just keep throwing money at defense technology? We spend more on defense per capita than the next top three nations combined- do you realize that includes North Korea, widely considered to be a "military state"?

The problem is that taxes are all interlinked, because they're all paid by you and me out of the same place- our bank accounts. So when federal taxes go up, guess what? That means more political pressure on state and local politicians. They have to cut local and state taxes because people are screaming blue bloody murder that their taxes are outrageous. Perfect example- MA's governor, Mitt Romney, wants to slash taxes- but his last budget severely cut funding for a lot of very important stuff- programs for the mentally ill and money for state colleges, for example. There's no money left in the coffers for improving the state's roads- even though we have a fantastic system of arteries in Boston now, soon as you get off them, you find some of the shittiest roads in the country.

You want local services to be locally funded? Fine. Cut the money out of the budget- don't redirect it to "terrorism" crap or defense stuff- I want to see my federal tax bill for 2005 go down. Second, get corporations back to footing half the taxes, like they did in the 1950's, instead of the 2% of today.

The things wrong with the educational system goes far deeper than money, throwing more money at it without solving the other problems would only make things worse, IMO.

When schools have to shut down all their extracurricular activities and students have to share BOOKS in this day and age- uh, I beg to differ. Throwing money is EXACTLY what needs to be done. But, enior citizens hate taxes, don't have kids in school, and vote in large numbers.

Re:just what we need

[nmos]

I see. So we should just keep throwing money at defense technology? We spend more on defense per capita than the next top three nations combined- do you realize that includes North Korea, widely considered to be a "military state"?

All good stuff but even if you consider NASA part of "defense technology" and ignore all of the areas it contributes to it's still only a very tiny fraction of our defense spending. Even cutting NASA completely wouldn't change the stat you quoted at all.

Re:just what we need

[bhima]

I mostly agree with your post, but since I'm a space fan boy I can't resist to comment. I think NASA is researching stuff that will get funded and unfortunately to do that they begin with technology with obvious military uses. I've read a lot of articles on this propulsion system and I just can see it ever really making it out of military use. The efficiency of this is poor and that would drive costs up and that is one of the things that killed the concord. I fly to the US a couple of times a year and while I would like to have a dramatically shorter flight I'm not willing to pay more than I already have to (although I generally upgrade)

Oh and I find you comments about school books to be misplaced. The real problem with school books is that the whole publishing system is a corrupt money grab and is unrelated to the corrupt money grab that exists in the industrial military complex (other than the fact they both shows flaws inherent in the capitalist system).

Re:just what we need

[Bi()hazard]

The parent post sounds suspiciously like a troll, but it's been modded up enough to deserve an analysis of its claims.

Great. So now we'll have missiles that can do mach 15. It's being billed for aircraft as well, but nobody seems to have addressed issues of, gee, say, it only being useful at incredible altitudes. Nevermind that the airline industry is crumbling requiring massive bailouts from the Feds, and the only supersonic aircraft to date to do commercial passenger flights was never profitable in almost 40 years of operation.

Most people don't like missiles, but access-to-space vehicles that operate at incredible altitudes are very useful. We have a lot of very useful satellites up there, and these "space planes" could make those satellites a lot cheaper. But you do have a point on the airline industry. The Feds waste endless sums of money bailing out companies that fail to innovate and offer infamously poor service, and then the feds turn around and regulate them into the ground to prevent terrorism. Flying, which was once a decadent luxury, is now a painful ordeal. The airline CEO's are riding a gold mine of federal bailout money while the taxpayers get screwed.

What can we do to restore the airlines? I'll tell you what. We need to turn them into desireable luxuries affordable to the masses.

Today, when you enter an airport, you're destined to spend hours sitting around being bored while waiting for your plane. You'll go through a pain-in-the-ass security procedure that doesn't secure much at all. And then you'll be packed into cramped seats like sardines.

How can we solve all of these problems without spending vast sums of money, even though the people running the airlines are corrupt, money grubbing fiends?

Easy-turn all those weaknesses into strengths! Through the power of sex. Take all the money you would spend on bailing out the airlines, and use it on a massive campaign to fight sexually transmitted diseases and unwanted pregnancy. When people show up at the airport, the security check will consist of attractive members of the opposite sex strip-searching them to ensure health, hygiene, and the use of contraceptives. The hours of waiting for delayed flights will *fly* by as they turn into massive orgies. Being packed like sardines on the plane will be a good thing now. (we just have to make sure seating arrangements keep people in compatible groups, perhaps ordered by age, with plenty of cute stewardesses and stewards to guarantee everyone has a good time?)

This approach has endless benefits: Everyone will want to fly, turning the airline business into a highly competitive, profit-filled arena. Everyone will have a great time, making life better for the common citizen. Illegal prostitution will become a thing of the past, and the safety checks will result in huge reductions in national healthcare expenses as problems are prevented before they spread. And how does this relate to scramjets? Ooh, imagine the possibilites of doing all that in orbit, with zero gravity! I, for one, welcome our weightless airline sex overlords. And underlords. Depending on whether you're a top or bottom.

I'm sick of NASA justifying themselves as an organization for exploration and science- when they're instead spending most of their time (and my money) on weapons platform research and lining defense contractor pockets.

NASA is actually one of the less defense-oriented research organizations. Believe it or not, the department of defense is the single most influential source of funding for pure science in this country. Nobody else wants to pay the bills. We'd see fewer weapons platforms if the government spent MORE on pure science that won't be applied for another decade. But as long as scientists can only get funded by playing the DoD's game, we're going to see giant robots wielding laser cannons before a cure for cancer. Simply kill the giant robot programs without increasing spending on pure research, and you'll see unemployed scientists movi

engine design

[Lehk228]

After reading the article and looking at the diagram i wonder how the vulnerability of scramjet engine compares with a turbojet or turbofan when it comes to impacting birds and or bats, though at this time i am sure these engines are only being used at very high altitudes and in controlled conditions but if they make it into production fighter aircraft they will be used at lower altitudes. the lack of anything blocking off the path of the air in the diagrams makes it look almost as if an object would pass completely through the engine without damaging it, though i'm sure the object would be burnt to a crisp.

Re:engine design

[Beryllium Sphere(tm)]

It sounds like the engine depends on careful management of shock wave locations and heat profiles. Running a foreign object through could not be good.

On the other hand these are for speeds above Mach 3, at which you'd better be in very thin air or you'll start melting your vehicle. There aren't many birds at SR-71 cruising altitudes.

It is just what we need.

[Behrooz]

It is just what we need. Or rather, it's a good stepping stone on the way to orbit.

Mach 15 at 100,000 feet is 10,200 MPH, which is also roughly equivalent to the following critical hurdles to cheap space travel:

10% of the ~185-mile altitude required for a stable orbit.
59% of the ~7.7 km/sec required to achieve low-earth orbital velocity.

NASA's budget is a drop in the bucket, approximately $15B out of total discretionary spending exceeding $850B, with a total federal budget exceeding $2.2 trillion... hah.

Hypersonic aerospace research is a good idea simply on its own merits, regardless of present applications. I certainly look forward to 90-minute sub-orbital shuttles from London to Tokyo, and being able to put things in orbit for less than $10,000/pound.

Affordable?

[bStrom]

The article says that the scramjet will be "affordable", but what does that really mean? Affordable compared to current commercial technology? Affordable compared to current scramjet technology?

The affordability, more than anything else, will determine whether this technology is adopted. This engine might get you to your destination faster, but if it costs 10x as much the majority of fliers (and airlines) won't pay.

Great...

[Dayze!Confused]

All we need is more ways to shoot missiles. Hey maybe we could sell them to two combating countries so they can take each other out and then we can go invade them for having weapons of mass destruction.

cheaper

[Anonymous Coward]

scram jets could be cheaper because they use surrounding atmosphere to mold a 'virtual nozzle' to direct exhaust. This means less weight, less fuel...

Also, the technology can hypothetically be turned into a radial design. There are descriptions on the net, I'm just to lazy to hunt one down.

Scramjet never actually tested

[commodoresloat]

There was no scramjet "test." The whole thing was done in a NASA basement, with simulated scramjets-powered aircraft which were made to look like they were being tested. The reality is the tests never happened. Wake up people!

Zero to 5000 in 10 seconds?

[serutan]

Did I read this right? ...scramjet engine fired for a planned 10-s test, achieving an incredible Mach 7, or 5,000 mph.

It reached 5000 mph in TEN SECONDS? Holy crap, dude!
If this is right I am truly impressed. Could a human passenger survive that acceleration?

Re:Zero to 5000 in 10 seconds?

[Lord Kano]

Not exactly, it was carried atop a regular airplay at several hundred miles per hour, then the rocket booster kicked it up to the cruising altitude and THEN the scramjet engine was engaged for the 10 second burn.

It's damned impressive but it's not like it accellerated to 5000 mph from a standstill.

LK

Re:This begs the question

[Anonymous Coward]

Why do we need to go mach 15 anyway?

Because some people just aren't satisfied with the shave they get from their Mach 3?

Re:I call your bluff, sir

[FatBobSmith]

Tang.

Re:I call your bluff, sir

[gilroy]

OK. By the way, this is from less than two minutes of a Google search... it's particularly low-hanging fruit available to anyone who's open enough to actually, you know, look.

"Commercially available infant formulas now contain a nutritional enrichment ingredient that traces its existence to NASA-sponsored research that explored the potential of algae as a recycling agent for long duration space travel." (ref)

Ski wear: "The NASA association began back in the 1970s, when Comfort Products adapted astronaut protective clothing technology to ski boot design. Specifically, the company borrowed heating element circuitry that kept Apollo astronauts warm or cool in the temperature extremes of the Moon, and used it to create built-in rechargeable footwarming devices that were supplied to leading ski boot manufacturers." (ref, emphasis added)

"In 1965, Johnson Space Center contracted with the University of Minnesota to explore the then-known but little-developed concept of impedance cardiography (ICG) as a means of astronaut monitoring. A five-year program led to the development of the Minnesota Impedance Cardiograph (MIC), an electronic system for measuring impedance changes across the thorax that would be reflective of cardiac function and blood flow from the heart's left ventricle into the aorta... the cost of the thermodilution technique [the old, invasive way] runs five to 17 times that of IQ monitoring [the new, NASA-developed way]"(ref)

"GROUND PROCESSING SCHEDULING SYSTEM - Computer-based scheduling system that uses artificial intelligence to manage thousands of overlapping activities involved in launch preparations of NASA's Space Shuttles. The NASA technology was licensed to a new company which developed commercial applications that provide real-time planning and optimization of manufacturing operations, integrated supply chains, and customer orders" (ref)

"STRUCTURAL ANALYSIS - This NASA program, originally created for spacecraft design, has been employed in a broad array of non-aerospace applications, such as the automobile industry, manufacture of machine tools, and hardware designs."(ref)

"SCRATCH-RESISTANT LENSES - A modified version of a dual ion beam bonding process developed by NASA involves coating the lenses with a film of diamond-like carbon that not only provides scratch resistance, but also decreases surface friction, reducing water spots." (ref)

"MICROSPHERES - The first commercial products manufactured in orbit are tiny microspheres whose precise dimensions permit their use as reference standards for extremely accurate calibration of instruments in research and industrial laboratories. They are sold for applications in environmental control, medical research, and manufacturing."(ref)

"SOLAR ENERGY - NASA-pioneered photovoltaic power system for spacecraft applications was applied to programs to expand terrestrial applications as a viable alternative energy source in areas where no conventional power source exists."(ref)

"DIGITAL IMAGING BREAST BIOPSY SYSTEM - The LORAD Stereo Guide Breast Biopsy system incorporates advanced Charge Coupled Devices (CCDs) as part of a digital camera system. The resulting device images breast tissue more clearly and efficiently. Known as stereotactic large-core needle biopsy, this nonsurgical system developed with Space Telescope Technology is less traumatic and greatly reduces the pain, scarring, radiation exposure, time, and money associated with surgical biopsies."(

What is a scramjet?

[p0]

From the article:
The supersonic combustion ramjet, or scramjet, uses no rotating parts. In a conventional ramjet, the incoming supersonic airflow is slowed to subsonic speeds by multiple shock waves, created by back-pressuring the engine. Fuel is added to the subsonic airflow, the mixture combusts, and exhaust gases accelerate through a narrow throat, or mechanical choke, to supersonic speeds. By contrast, the airflow in a pure scramjet remains supersonic throughout the combustion process and does not require a choking mechanism, which provides optimal performance over a wider operating range of Mach numbers. Modern scramjet engines can function as both a ramjet and scramjet and seamlessly make the transition between the two.
Get the pdf version here

Re:I call your bluff, sir

[mj_1903]

How about any of NASA's R&D to do exactly those things? If I recall correctly, the shape of the wings on many aircraft today are a direct descendant from research that NASA did on aircraft wings. Interestingly you may also not know that NASA found that a wing that was upside down with a small lip on the end was actually the best wing in terms of performance.

Composite structures in aircraft, such as the tail of the 777 or much of the Airbus super jumbo, owe a great deal to NASA's research.

Many new things have been learnt about the human body thanks to NASA research into human behaviour, in areas such as extended stays in isolation, the endurance of the human body and team work.

Many key elements of computers owe a lot to NASA funding miniaturisation for space craft and this has had a run off effect in many areas of human life.

Other posters have mentioned other areas, so I will leave it at that.

Old News?

[aussie_a]

I remember hearing about them doing this (or at least something very very similar) on the radio a couple of months ago. And that was Australian radio, I always thought Australia was the last place news reached.

Did they re-do the experiment/is it something new? Or is slashdot the last place news reaches?

Re:Old News?

[donscarletti]

Sorry, that was the wrong test I just linked to.
This is the one that actually worked

Re:Old News?

[Planetes]

Actually no, this was a seperate experiment conducted by NASA while the experiment you are referring to was conducted by Australia. Both were scramjet flights, they were totally different designs though. The NASA experiment is the second of 3 flights. The first was aborted due to a failure with the control surfaces on the pegasus booster. The third is upcoming.

cool...

[zxflash]

interesting read, if anybody is looking for more info nasa has a good writeup on scramjets...

NASA - What's a Scramjet?

Security concerns

[britneys 9th husband]

As cool as it would be to fly from New York to Tokyo in 90 minutes, I wonder if anyone has thought about the security concerns related to passenger jets that can travel 10,000 mph. Often during events like the Super Bowl or political oonventions, they'll put up a no-fly zone around a 5 or 10 mile radius so the military has time to shoot down any threatening aircraft. Problem is, at 10k mph, you can cover 1,000 miles in just 6 minutes. Does this mean all air travel in the entire Northeast would need to be shut down during the Republican convention in NYC? What kind of a no-fly zone would be needed around Washington, DC?

Don't get me wrong, I'm all for advancing technology, I just wonder how we would be able to handle a world where a terrorist flying a stolen or hijacked aircraft over Chicago could be less than 5 minutes from the White House.

Re:Security concerns

[schneidafunk]

You have to consider how hard it would be for a terrorist to take over a plane if it only takes a couple of minutes to fly from one destination to another. By the time you get up to attack the pilot, you've already landed!

Thats a big...

[Anonymous Coward]

23Gs? That would really, really suck. A 150lb dude (average /.er, soaking wet) would be slammed into his seat with like three and a half TONS of force. Anyone want to go take the tires off their car and then lay under it for 10 seconds? Let us know how you feel afterwards, ok? Thanks!

And even if you were in the center of a 6 foot ball of bubble wrap, I doubt your organs would survive the punishment. A three pound (2% of 150) brain? 70lbs in your skull. Would your heart even beat when it felt like 17lbs?

But I suppose we should look at the bright side. At least at 23Gs you could claim to have a 10lb penis!

"Hey baby... this one time..."


(Hmm, better post this AC...)

Very interesting technology

[Lisandro]

I just gave the article a read; very neat stuff. No moving parts for (basically) a very fast jet engine is nice. Also, it's possible to use hydrogen as fuel. Neat.

What i wonder is how feasible will it be to use in a passanger plane. The engine needs to have air fed in at Mach 3, and the article suggests using rockets. Those would need to be insanely big; and if you use a separate, "conventional" engine to reach that airspeed the aircraft becomes too complex.

Reusable engines for missiles !

[Barryke]

From article, the last paragraph:
Demonstrating these technologies, along with additional ground- and flight-test experiments, will pave the way for affordable and reusable air-breathing hypersonic engines for missiles, long-range aircraft, and space-access vehicles around 2010, 2015, and 2025, respectively.

Uhh? "demonstrating..reusable..engines for missiles" ?

Are we talking 'homing nuke' ?

The order of possible applications... Just great!

[silverdr]

"Scramjets will enable three categories of hypersonic craft: weapons, such as cruise missiles; aircraft, such as those designed for global strike and" [... possibly other unimportant bullshit applications... ] So isn't it just great that soon people will be able to kill other people with hypersonic Mach12 speed?!

Re:Air as a medium compared to space

[DaveVoorhis]

Planes do NOT go 'up' because of low pressure above the wing. Otherwise, how would they fly upside down? An entertaining explanation is found at http://www.jefraskin.com/forjef2/jefweb-compiled/p ublished/coanda_effect.html

"a quieter ride"

[da5idnetlimit.com]

well, a scramjet will take you from an initial Mach 2-3 to the expected mach 7-10+ this technolgy is meant to achieve...

So you will still enjoy all the noise of the starting point up to mach 1, then have a nice, quiet acceleration to mach 2-3, and then suddenly leave all sound you produce about 500-600 feet behind you, instead of just the 70 feet sound buble displacement you enjoy at mach 3.

the whole point is that to you it will be quite silencious...but it really have to be made in high altitude...

If you were to engage the scramjet at low altitude (say launched as a missile from a mach 2.4 fighting plane) just the sound wave decelerating from the missile at low altitude would be sufficient to damage any building within a 2 mile radius...not to mention deafening a few tousand people.

Then, on impact, I think you can dispense with unstable/dangerous explosive...
you just need some hyperdense material at the tip, say 5 kg depleted uranium.

Now, if you caculate the inertia of 5 kg at mach 7-25, you will find it's a very damaging little kinetic monster you just created.

after all, the FIRST implementation of that thing is to be a missile in 2010-2015...so lets see what the probable effects will be...

E=mv^2

5000grams*(330m/s*(mach 7 to 25))^2

5000*(5336100 to 68062500)
26 680 500 000 to 340 312 500 000 Joules at impact...seems quite an energy dissipation problem...for the target, I mean 8p

my physics class is quite old now, feel free to privide the right formula or to correct me on any point... 8)

Airlines NOT getting bailed out

[jgardn]

Most people don't like missiles, but access-to-space vehicles that operate at incredible altitudes are very useful. We have a lot of very useful satellites up there, and these "space planes" could make those satellites a lot cheaper. But you do have a point on the airline industry. The Feds waste endless sums of money bailing out companies that fail to innovate and offer infamously poor service, and then the feds turn around and regulate them into the ground to prevent terrorism. Flying, which was once a decadent luxury, is now a painful ordeal. The airline CEO's are riding a gold mine of federal bailout money while the taxpayers get screwed.

Sounds like you should cast your vote for Bush. He has repeatedly refused to bailout the airline and rail industries. The Republicans aren't into that corporate corruption and corporate welfare thing. Why do you think Enron, Anderson, and others are getting prosecuted now and not during the Clinton years, when they were at their heyday?

The Democrats talk a lot about how the Republicans are the party of the rich and how they are 100% behind the corporations. I have news for you. The richest senators are Democrats, not Republicans. Heck, John Kerry and co is worth more than ten times what Bush and co is worth! And the Republicans are all for letting wasteful, poorly managed companies take a dive to leave room for new, young, vibrant companies. The Democrats will do anything to keep their buddies' companies alive.

Where do the Republican's principle donations and loyalties lie? With homeowners and small business people. Why do you think that they are pursuing cutting the income tax for the highest wage earners? Because the highest wage

• earners

are those who are

• becoming

rich, not who are already rich. These are the small business people who finally get their break and are expanding their business to meet the demand. And the Republicans are pursuing to cut the death tax because it hurts the small business owners who don't have a team of fifty lawyers and accountants on hand to setup trust funds to make sure their cash gets into their childrens hands.

Democrats talk up a storm - but what have they done for the little guy? Look at their real record, and you'll see they're all about keeping the money in the hands of the rich, preventing others from getting rich, and keeping the poor man on the dole. This runs right along with their historic racist and tyrannical attitudes, which still persist with current members of the Senate. (The only member of the senate that is also a part of the KKK is Senator Robert Byrd, a democrat.)

Remember, the first and only man to strike another on the floor of the Senate was a democrat. And it was over slavery and the fact that the democrat didn't want to give it up, even though the overwhelming public opinion both north and south of the Mason-Dixie line was against the democrats. The democrats started the civil war by firing on federal soldiers. The democrats enforced segregation. It wasn't until the Republicans were able to regain some power in the senate and house that segregation was ended.

So if you are against corporate welfare and you think that corrupt corporate leaders should get jailtime, vote Bush and Republican.

Mark this flamebait. I know you guys hate hearing the truth. It drives the democrats nuts because they can't refute it, so instead they try to shut us up and prevent us from exercising our right to free speech.

Fast and loose with those stats

[rk]

Spending more on defense per capita has nothing to do with being a military state. North Korea's militaty expenditures as percent of GDP are way higher that the US statistic.

Hell, I bought a handgun once during a year I had practically no income. By your definition, I was a military state in 1986.