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Scramjet Test Successful

michael posted about 13 years ago | from the zero-to-six-thousand-in-one-second dept.

Technology 300

An Anonymous Coward writes: "The Sacramento Bee is running this story about the first powered device to achieve "hypersonic" speeds in the Earth's atmosphere. In a series of DARPA-sponsored tests, at Arnold Air Force Base in Tennessee, a scramjet engine, encased in a titanium projectile, was fired from a 130-foot cannon, at an initial velocity of Mach 7.1. The scramjet's engines then ignited, and the object moved another 260 feet, in just 30 milliseconds, before it came to rest in a series of steel plates designed to halt the flight. Peak acceleration: about 10,000 G's. Elapsed time, including cigarettes & pillowtalk: less than a second. PS: According to this nifty page at NASA, Mach 7.1 is about 5406 MPH, whereas 260 ft, per 0.03 seconds, is about 5909 MPH."

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first fist (-1, Troll)

Anonymous Coward | about 13 years ago | (#2229024)

wray

Re:first fist (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229239)

Ayúdeme. Mis pantalones están en el fuego. Necesito buen código poner hacia fuera las llamas. No puedo encontrar buen código aquí. Mis pantalones del diablo están en el fuego.

Crapflooding - for real! (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229289)

Instead of crapflooding the Slashdot I managed to literally crapflood the toilet at my workplace. I sprayed diarrhea all over the bowl, filled it with foul smelling semi-liquid and left it unflushed!

How to make your own supersonic missile ... (1)

snowtigger (204757) | about 13 years ago | (#2229028)

Rent a Concorde and fill it with a lot of explosives. It's that easy ...

Great idea! (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229056)

Oh sure, what a great idea! I rent those things all the time. They'll never miss it.

Re:Great idea! (1)

snowtigger (204757) | about 13 years ago | (#2229280)

Well, as the Concordes are currently grounded, they probably wouldn't notice anything ;-)

"I'll just borrow it for a little while, OK ?"

Re:How to make your own supersonic missile ... (1)

markyd (517099) | about 13 years ago | (#2229161)

Who needs explosives, just put some shards of metal on the runway.

Actually, this has become a joke in France ... (0)

Anonymous Coward | about 13 years ago | (#2229216)

People saying that the mus in luxe was Paris Gonesse (10 Km) using the Concorde.

BtW, this IS bad taste... 8)

Urban Legend (1)

Cheebus (517855) | about 13 years ago | (#2229029)

So, anyone want to set up a pool betting when the first "then we strapped a SCRAMJET on the back of Bob's old VW Bus" story appears?

Re:Urban Legend (0)

Anonymous Coward | about 13 years ago | (#2229050)

They'll sure win another Darwin award for this..
Smbdy already stucked some jet engine on the roof of his Chevy or smthing.. if you haven't read this yet, the manuals are here [darwinawards.com]

I can see my first flight on one these babies now (5, Funny)

case_igl (103589) | about 13 years ago | (#2229031)

Ladies and gentlemen, welcome aboard LotsaCashSpentDevelopingThis Airways.

Flight Attendant #1:
"Once we reach our cruising altitude we will begin our complimentary beverage service. Coke products are free while beer, wine, and liquor may be purchased for..."

(interrupted by Flight Attendant #2):

"LotsaCashSpentDevelopingThis Airways welcomes you to Paris DeGaulle Airport. The local time is 12:14pm."

Re:I can see my first flight on one these babies n (1)

smasch (77993) | about 13 years ago | (#2229058)

What's the point? Do you really think flying 10x faster will get you there much faster?

Time to get to airport: 2 hours

Time waiting at airport: 1 hour

Flight time: 30 minutes (probably longer or shorter, depending on destination, weather, etc.)

Time waiting for bags: 1 hour

Time getting transportation: 30 minutes

Time getting to where you want to go: 2 hours
(Yes, all numbers are approximate. YMMV)

I don't think flying faster would help...

Re:I can see my first flight on one these babies n (1)

N Monkey (313423) | about 13 years ago | (#2229071)

What's the point? Do you really think flying 10x faster will get you there much faster?

I guess you've never flown from Australia to the UK (or vice versa). I'd tolerate quite a bit to reduce the ~22hrs spent in the air....

...although, judging from the acceleration rates, being squashed flat at take off like a cartoon character probably is a bit more than I'd put up with, not to mention the sudden braking at the destination ... :)

"The prototype, ... was destroyed when it punched through a series of steel plates designed to halt the flight. "

Ouch!

Simon

Re:I can see my first flight on one these babies n (1)

Foss (248146) | about 13 years ago | (#2229105)

Looks like it's time for someone to invent the physics-defying-star-trek-inertial-damper things then.

That reminds me.. Must send off for that patent. :)

Re:I can see my first flight on one these babies n (1)

lars_stefan_axelsson (236283) | about 13 years ago | (#2229254)

Well, that part of Star Trek isn't that physics defying. It's quite simple really, all you have to do is push a sufficiently heavy object in front of you, the gravity of which will counteract any forces felt from acceleration.

Sure for shipboard use you'd want a sufficiently heavy object of small compass, such as a black hole...

Granted, getting such a system to work, is a tall order, but that's an engineering problem, not a physics one. ;-)

No, what irks me about the inertial dampers is the human factors thing; with the crew being thrown out of their chairs with every phaser blast, having to take precious time out to scramble back into them, why on earth don't they have seat belts? ;-)

Re:I can see my first flight on one these babies n (0)

Anonymous Coward | about 13 years ago | (#2229291)

why on earth don't they have seat belts?

Well, there are morons who refuse to wear seat belts while driving a car because they feel the belts restrict their movement.

Re:I can see my first flight on one these babies n (1)

Da Web Guru (215458) | about 13 years ago | (#2229078)

I think that the market for these engines is not your average Chicago to New York flights, but your New York to Paris/Sydney/Hong Kong/Tokyo/[insert your favorite overseas city here] type of flights, i.e., those flights that are already over about 6 hours (closer to 10+ hours) with conventional aircraft. They have to be on those longer flights because they have to fly so high up before going supersonic to avoid having the shockwaves shatter every pane of glass from New York to Los Angeles. Besides, you can't just take off at mach 1 (much less mach 7.1); that would be kind of dangerous if you weren't in a space-shuttle quality harness...

Re:I can see my first flight on one these babies n (0)

Anonymous Coward | about 13 years ago | (#2229251)

but your New York to Paris/Sydney/Hong Kong/Tokyo/[insert your favorite overseas city here] type of flights...

Cool. But the day I'd fly from New York to New York, I'd have grown feathers first.

Re:I can see my first flight on one these babies n (0)

Anonymous Coward | about 13 years ago | (#2229224)

Hey monkeyboy, get on a 16 hour flight to Sao Paulo or 23 hour flight to Tokyo. THEN you'll understand why this is great.

Your 30 min flight from Cleveland to Akron isn't what science is trying to improve.

Re:I can see my first flight on one these babies n (1)

gazbo (517111) | about 13 years ago | (#2229267)

Flight time: 30 minutes (probably longer or shorter, depending on destination, weather, etc.)

And I always thought it was a stereotype that Americans didn't realise there were countries outside the States.

Oh, sorry, you've heard of Mexico and Canada too - I saw it on South park ;-P

Re:I can see my first flight on one these babies n (1, Funny)

Anonymous Coward | about 13 years ago | (#2229063)

and...

"Please wait while our molecular reconstructor negates the effect of the 10,000G acceleration. We will begin by fixing our first-class passengers..."

Re:I can see my first flight on one these babies n (1)

The Dark (159909) | about 13 years ago | (#2229080)

Of course, if they are going to use these for commercial flights, I suggest we all invest heavily in steel plate manufacturing companies.

Re:I can see my first flight on one these babies n (0)

Anonymous Coward | about 13 years ago | (#2229173)

Investing in Coffin Manufactuars would be more appropriate.

Re:I can see my first flight on one these babies n (2, Funny)

sopuli (459663) | about 13 years ago | (#2229233)

Of course at 10kG, by the time they arrive in Paris, all passengers will have changed into some kind of schnitzel.

Read the article, plz. (2)

cprael (215426) | about 13 years ago | (#2229032)

According to this nifty page at NASA, Mach 7.1 is about 5406 MPH, whereas 260 ft, per 0.03
seconds, is about 5909 MPH.



Well, given that the projectile in question was accelerating at ~10K G for that 260 ft, from a starting velocity of Mach 7.1, one would expect the mean velocity over the 260 ft to be somewhat higher, eh?

Re:Read the article, plz. (1)

Cheebus (517855) | about 13 years ago | (#2229044)

I believe that the 10K Gs was referring to the acceleration from rest until it hit the target....in the barrel: 130 feet to reach 5400mph (28080000 feet per hour -- 468000 feet per minute -- 7800 feet per second in a fraction of a second....10k Gs seems pretty reasonable there

Re:Read the article, plz. (1)

baldeep (213585) | about 13 years ago | (#2229077)

I think 10K G's is the peak (instantaneous) acceleration.

Re:Read the article, plz. (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229099)

YOU read the article, foo'.

Re:Read the article, plz. (1)

m2 (5408) | about 13 years ago | (#2229103)

Starting at 2300 m/s and ending at 2600 m/s over 80 m gives you an acceleration of (2600**2-2300**2)/(2*80) ~ 9200 m/s**2, which is ~ 1000 g. OTOH, from 0 m/s to 2300 m/s over 40 m is 66000 m/s**2 (~6700 g), but nothing actually says the acceleration was uniform so 10000g peak inside the barrel is not that far fetched.

aint that fast (0)

Anonymous Coward | about 13 years ago | (#2229170)

Think about it, Formula One Cars dont go over 5 G, Nascar probably dont even get 1G, being big slow machines an'alll. But 10kG is pretty fast.

The reported speed is right, The 'tube thingy' wasn't instantly traveling at 10k G, because if it was, their wouldn't be any G', it had to accelerate, and theirs the main diffence in MACH, but it also must have been at a certain hight, or at different hights, and MACH changes at different altitudes.

T

Re:aint that fast (1)

Wiktor Kochanowski (5740) | about 13 years ago | (#2229227)

Think about it, Formula One Cars dont go over 5 G, Nascar probably dont even get 1G, being big slow machines an'alll. But 10kG is pretty fast.

Just a nitpick: if you want to use SI units of measure, take some time to get them right. The unit of acceleration you are referring to is "g", equalling about 9.81 meters/sec^2, while "G" is the gravity constant. Of course, then 10,000 g comes off rather misleadingly as 10 kg, which is why it's a good idea in the first place to use the official UM, meters per second squared.

Re:Read the article, plz. (2)

Stephen Samuel (106962) | about 13 years ago | (#2229245)

$ units '260ft/5406mph' seconds
* 0.032791847
/ 30.495385

Given that only 1 significant digit was given, .03 seconds is appropriate for mach 7.1. (remember your rounding rules). I presume that nasa's measurements were more accureate than 1/100th of a second, but they just didn't bother to print all those extra digits in the news release. Most news releases are edited by english majors, not physicists or mathematicians. They probably thought that .03 seconds was as accurate as mach 7.1 (fewer significant digits, but the same number of printed digits).

Re:Read the article, plz. (1)

AtomicBomb (173897) | about 13 years ago | (#2229292)

Well, instantaneous acceleration can be very large. (eg, the deceleration when a hard disk crash-landed on the concrete floor can be much larger than 100G).

But, 30ms of 10000G acceleration is still impressive. I hope they will have a method to "tune down" the acceleration. If not so,I will be surprised if they can mount any modern electronic circuits to the scramjet plane/missile/bomb/cannon shell. AFAIK, GPS module (civilian) can at most handle 25G. Even if the military version is ten times better, we still have a long way to go.

OT:Metric please? (1)

not-quite-rite (232445) | about 13 years ago | (#2229039)

Very impressive indeed.

But if possible, could the posts include a conversion into metric.

Its just it takes me a little while to do the conversion on my slide rule.

I am sure the rest of the civilised world(ie SI unit using countries) can understand.

Thankyou.

Re:OT:Metric please? (0)

Anonymous Coward | about 13 years ago | (#2229083)

But if possible, could the posts include a conversion into metric.

Actually, this is something to be done on the client side. Pipe your html through a filter that changes "x mph" to "1.609344*x km/h" when it sees it. You can even round the result to get the same number of significant digits as the original number. Of course, uncivilized Americans can make a script that does exactly the opposite conversion.

Re:OT:Metric please? (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229253)

Pipe your html through a filter that changes "x mph" to "1.609344*x km/h" when it sees it.
Please do NOT do this. As we all know from the amount of pant-wetting that happened over SmartTags, ANY sort of client-side HTML filter is a completely illegal infringement of my copyright.

--- CmdrTaco

NOT OT (Re:OT:Metric please?) (0)

Anonymous Coward | about 13 years ago | (#2229155)

Why would a request for metric be offtopic?
After all, besides UK and UK 2.0 (= USA) all
the world is metric. So for those 5%...
Ah, but /. is hosted by those 5% for those 5%.
Too bad, nevermind.
OK, keep your imperial measures, your non-standard
cellphones and your non-ISO paper sizes.
Just pull your nukes out of the rest of the world,
willya?

Re:NOT OT (Re:OT:Metric please?) (0)

Anonymous Coward | about 13 years ago | (#2229228)

UK is still using Imperial? I KNEW we backed the right side in WW2!!!!

Anti-Metric Posse in da muthafuckin HIZOUSE!!!

Re:OT:Metric please? (2, Funny)

brocktune (512373) | about 13 years ago | (#2229175)

As a guide to our international readers, here is a quick reference. Here in the US, meters are what the gasman reads. Gram is a kind of cracker. Kilos are what is hidden in tire wells at the border crossing in Tiajuana. Megatons are what we drop on people who speak in funny languages.

Re:OT:Metric please? (0)

Anonymous Coward | about 13 years ago | (#2229247)

...and millimeters are what we measure our dicks in.

Re:OT:Metric please? (2, Funny)

erlando (88533) | about 13 years ago | (#2229317)

In the rest of the world; feet are what we walk on, miles is some dude named davis and yards are what is on the back side of the houses..

Pardon me if I'm wrong (1)

Ryvar (122400) | about 13 years ago | (#2229040)

But doesn't the speed of sound change with the air-pressure? If I remember highschool physics correctly, sound has a higher velocity in a denser medium.

--Ryv

SOUND SPEED IS @ SEA LEVEL;;; (0)

Anonymous Coward | about 13 years ago | (#2229232)

sound speed is indeed calculated at sea level...

it is just a REFERENCE Speed !!!

wich means... Take Ariane (French Space Shipper)
It goes Mach 17. Out in space. Where THERE IS NO SEA LEVEL.

sound has higher velocity at denser medium. But we tend not to consider too much atmospherics variation
(On a cloudy day with H2O in the air, MACH refernce point won't change to accomodate your Anal Closed mindedness 8)

Re:Pardon me if I'm wrong (2)

rneches (160120) | about 13 years ago | (#2229249)

Yes. The speed of sound increases with the density of the medium through which it propogates. For instance, the speed of sound through the crossection of average slashdot posters is aproximatly 8450 M/s.

Re:Pardon me if I'm wrong (1)

dingbat_hp (98241) | about 13 years ago | (#2229312)

But doesn't the speed of sound change with the air-pressure?

Yes, but that's not so relevant. It's easy to make things go faster - just accelerate them. What gets to be really hard is making them travel at a higher Mach (speed relative to the current speed of sound), because most aerodynamic behaviour isn't dependent on speed, it's dependent on Mach. The behaviour and position of shock waves depends on the Mach, and that's the tricky one.

This isn't an exercise in making a fast projectile, it's an exercise in making an engine that can still generate useful thrust when travelling at high Mach (and doing it in free-flight, not a tunnel).

intriguing thought (1)

sniepre (517796) | about 13 years ago | (#2229045)

The prototype, which resembles a gothic spire and measures just 4 inches in diameter, was destroyed when it punched through a series of steel plates designed to halt the flight. If this scramjet engine technology is so small, could this possibly be retrofitted, (I have no idea of the fuel needed to power this or it's economy, but im speaking theoretically) to give proper thrust needed for larger vehicles, such as, a jump-jet style civilian vehicle? The flying automobiles out of television sci-fi? Is this possible or am I just not getting the whole idea..

Re:intriguing thought (0)

Anonymous Coward | about 13 years ago | (#2229072)

The flying automobiles out of television sci-fi?

With some moron talking on his/her cellphone while driving? No thanks.

Re:intriguing thought (0)

Anonymous Coward | about 13 years ago | (#2229137)

you really are NOT getting the whole idea - does the word 'prototype' mean anyhting to you?

doofus.

Re:intriguing thought (1)

sniepre (517796) | about 13 years ago | (#2229192)

Prototype or not, that was not what i was referring to. I was simply referring to the core technology, which seems to be able to create a lot of thrust in a small package. Most likely, this is driven by some form of solid fuel, and would be unacceptable for use in a consumer vehicle, but I was just trying to get more information on such details. A working prototype is still better than vapors of a theoretical technology. ;)

Re:intriguing thought (1)

bdeclerc (129522) | about 13 years ago | (#2229186)

If this scramjet engine technology is so small, could this possibly be retrofitted


Nope, sorry. Basically a scramjet needs to be travelling at extremely high speeds before it can even function, that is why they launched it from a cannon. (Getting it up to operational speeds fast).

A scramjet airplane would need another type of engine to first get it up to multi-mach speeds

Re:intriguing thought (1)

dragons_flight (515217) | about 13 years ago | (#2229238)

It runs primarily on compressed liquid hydrogen and requires an air flow well in excess of the speed of sound to ignite. Hence firing it out of a cannon. Any use you make of this is going to require a rocket engine or really good jet engine to even get it started, but once it gets going the prediction is that it can reach Mach 10 or more which is better than most or all conventional rockets in Earth atmosphere IIRC. For weapons it looks great, perhaps also for launch vehicles. However anything involving people is a little iffy if you can't control the acceleration enough that someone can be semi-comfortable. But who knows, check back in 10 years and see what they've thought up.

intended use (4, Interesting)

rneches (160120) | about 13 years ago | (#2229270)

The idea behind these sorts of technologies (scramjets and ramjets) is to fly very efficently, especially in the higher atmosphear. The technology to beat, in this case, is non-air breathing propultion (a.k.a. rockets). Because scramjets are air breathing, it is not neccesary to bring along an oxidizer, allowing for considerable weight savings.

Because of this, scramjets are critical for efficent, practical single-stage-to-orbit vehicles. The idea is that you operate in scramjet mode until the atmosphear thins out too much to sustain combustion, and then you start adding your own oxidizer. This will effectively turn the engine into a rocket motor. With scramjets, you could build a shuttle that would actually be fairly inexpensive to operate. Also, since the most expensive part of any mission is boosting into low earth orbit, any savings in the first stages of flight would dramatically bring down to costs for any mission, but especially heavy ones (like a manned mission to Mars).

The other reason to develop scramjets is for their raw efficenty. The use fuel at a fantastic rate, but at Mach 7, the fuel per unit distance is exceedingly good. Instead of supersonic (in this case hypersonic) flight being a luxury reserved for Concorde flyers, it would become the cheap, practical way of getting around. Of course, it would only make sense for the really long flights (like Chicago to Sidny), but the implications could be trans-global flights that cost less than regional flights.

Scramjets are very, very cool, and not just because they go fast.

Re:intriguing thought (1)

budgenator (254554) | about 13 years ago | (#2229325)

From the darpa press release:
  • projectile is 20 percent scale, (full sized vehicle would be 0.5M, or 20 inches)
  • announcement was for the first ever flight of scramjet burning hydrocarbon fuel
  • second successful flight (included in announcement of first appearently 1st wasn't a fluke)
  • scramjets start operation at above Mach 5, (normaly you use a rocket motors to attain operating speed)
  • launched at Mach 7.1, peak accel approx.10K G's (Impressive that it held together and operated at all!)
  • additional launchers planned with higher-proformance projectiles and longer flight times in phase II testing
  • intended uses
    1. long-range hypersonic missiles
    2. kinetic-energy cannon projectiles (anti-tank, anti-ship stuff)
    3. access to space-vehicles (anti-satallite weapons?)

    no I don't think this is a technology that'll see much commercial or civillan use. The engines probably are fire once, and discard type technology. Fuel/Oxidiser econ would be better than a rocket engine no LOX to carry; but not as good as a normal jet emgine IMHO. The Russians used a missile with a ram-jet engine for air-defense, it convinced us not to fly U-2 spy-planes over their airspace.

Calvins Beanie (2, Funny)

squaretorus (459130) | about 13 years ago | (#2229055)

This is great - forget those stupid little rotor blades! 10K G from a small metal tube on his head - lets see Hobbes bounce him NOW!!!

Too Much Error to Criticize (1)

shredds (241412) | about 13 years ago | (#2229064)

I don't think that DARPA is using a stopwatch to calculate this to the nearest millisecond. They use very precise measuring tools that go to an accuracy far greater than a millesecond. The same goes for every number reported in the article. With all of these taken into account, the actual values probably differ than those reported by the illustrious 'sacramento bee'. Therefore, without the actual data, it is pointless to criticize or recalculate, since you are already using erroneous rounded data.

What to stick on that bad boy... (2, Funny)

Aqua OS X (458522) | about 13 years ago | (#2229066)

Honestly, all I can think of is "what could I tie to that thing?"

It's like I'm 8, I have a box of GI Joes that need to be punished, 1 scram jet engine, and a role of grey duct tape.

Re:What to stick on that bad boy... (1)

AnarchoFreak_00 (126755) | about 13 years ago | (#2229111)

The first thing that came to my head was "Can I strap this thing to my R/C car"?

8570km/h real speed, 1:10th scale car, 85,700km/h scale speed....That's pretty fast for a Alfa Romeo 156.

Somehow I think I'd lose the C from R/C.

Re:What to stick on that bad boy... (2)

Gordonjcp (186804) | about 13 years ago | (#2229204)

Sod that, just use a pulsejet [aardvark.co.nz] ...

---

Lameness, lameness, first time I've hit the lameness filter. My first posting was everything above that line. Maybe it *is* lame, but sometimes I haven't got a lot to say...

Come on, Slashcode authors, SORT IT OUT!

For us barbarians (2)

m2 (5408) | about 13 years ago | (#2229068)

260 ft is 79.25 m, 30 ms is 30 ms, so that's an average speed of 2.641 km/s or 9508 km/h. The initial velocity of 5325 mph is 2.380 km/s or 8570 km/h

Wow.

Re:For us barbarians (1)

wadetemp (217315) | about 13 years ago | (#2229070)

Thank you... I was just going to say something smart ass about "ok, so they made a cannon that can fire things at Mach 7.1," but you've shown the fact that they were launching a engine bullet out of this case rather than a rock or a cheese log actually made some difference.

I was thinking... wow, nice cannon. Now I'm wowing in concurance with your wow. O...K... time to go to bed.

Done before! (0)

Anonymous Coward | about 13 years ago | (#2229074)

did not the bell x-15 achieve this speed in the 60's!?

http://www.hq.nasa.gov/office/pao/History/SP-60/ ch -9.html

Re:Done before! (1)

jlemmerer (242376) | about 13 years ago | (#2229088)

yeah, it did, but the x-15 was rocket powered and not jet powered

Re:Done before - and since ;-) (1)

mikewhittaker (313040) | about 13 years ago | (#2229323)

Mach 7 ... now wasn't that supposed to be Thunderbird 1's cruising speed ?

Mind you, the date was supposed to be 2069.

passenger problem (2, Insightful)

jlemmerer (242376) | about 13 years ago | (#2229081)

if such high velocities are required to ignite the scarmjet, how will they do it in the future. firing it out of a cannon doesn't seem reasonable for me if you want to transport fragile goods such das humans. i heard rumors of bringing the scramjet equpped vehicle to high stratosphere with a carrier aircraft and then drop it to gain speed, but that also seems to be a rough ride.

Re:passenger problem (1)

sane? (179855) | about 13 years ago | (#2229117)

What makes you think they are doing this for passenger flight ?

Imagine a shell, or a missile, fitted with one of these scramjets. High speed = higher impact energy & greater range.

Maybe they will use them as part of NMD as a last ditch weapon? You can imagine a developed version having the speed to reach the reentry vehicle, and the energy to do something about it when it did.

As the fun over the unaffordability of a Concorde replacement has shown, passenger aircraft is the last thing on their minds.

Re:passenger problem (0)

Anonymous Coward | about 13 years ago | (#2229235)

EM rails is what is being discussed, from my understanding.

Re:passenger problem (2)

rneches (160120) | about 13 years ago | (#2229282)

There are a few ways of getting around this problem.
  • Drop the scramjet vehicle from a supersonic carrier vehicle.
  • Build a giant rail gun, like in Gundam Wing.
  • Attach JATO or RATO pods to the scramjet, and jetison them once hypersoninc speeds are reached.
  • Use conventional means to reach a high altitude, and acheive hypersonic ingition using a balistic dive.
  • Use an on-board oxidizer to fuel the scramjet like a rocket until atmosphearic ignition is possible.
  • Build the scramjet to work first as a jet. Once at maximum jet speed, lock the jet blades and operate as a ramjet. Once at maximum ramjet speeds, jetison the jet rotors and combustion chamber to expose a scramjet surface.
There are a couple of other reasonable ways, but those are the ones that come to mind.

$$$ (1)

Eso (205333) | about 13 years ago | (#2229084)

Alot of people complain about money spent on military/space research. I remember some outcry when the $125,000,000 (I think) Mars probe was left for dead and abandoned on Mars a while ago, and people bemoaned the waste of tax money. In this instance, $800,000, I don't think it's that big of a waste at all.

Let's see, Alex Rodriguez makes that much in 5 game days?

Re:$$$ (1)

ksb (517539) | about 13 years ago | (#2229147)

I agree, I also bet that NASA spent a shedload more on it's experiment and the damn thing fell apart, I wonder whether the NASA designers used KPH instead of MPH for its maximum speed ;)

Now I'm really scared of flying (1)

alnapp (321260) | about 13 years ago | (#2229087)

From the article

The prototype, which resembles a gothic spire and measures just 4 inches in diameter, was destroyed when it punched through a series of steel plates designed to halt the flight.

When and if they scale it up, I hope this part of the system is re-designed.

Knots, feet, miles, nautic miles... (1)

javaDragon (187973) | about 13 years ago | (#2229091)

Yeah, sure, but what does all this stuff give in real scientific units (meters, meters/second, etc) ?

Re:Knots, feet, miles, nautic miles... (0)

Anonymous Coward | about 13 years ago | (#2229124)

I agree, there's nothing "nifty" about converting between these antiquated units (unless multiplication by a magic number is the most sophisticated piece of math the guy can understand).

Great use in the world of air transport (1)

emn-slashdot (322299) | about 13 years ago | (#2229092)

Imagine being able to fly from New York to LA in 30 seconds!!! Wouldn't that rock???

Sucks you have to be greated by sheets of steel to slow you down to below-puking speeds.

Yeah that would rock, except for the fact... (1)

deathcow (455995) | about 13 years ago | (#2229157)

Yeah, that would rock, except for the fact that you'd need to travel at least 360,000 miles per hour to pull it off. Unfortunately that would ablate/vaporize your entire aircraft/rocket and all organic matter.

Why stop at such a puny detail ? 8) (1)

da5idnetlimit.com (410908) | about 13 years ago | (#2229242)

the goal is to get there.

Nobody said anything about mint condition 8)

Re:Great use in the world of air transport (1)

Nihilanth (470467) | about 13 years ago | (#2229269)

Unfortunately, being subjected to 10,000 G's would reduce a human being to the consistancy of a thin paste in short order.

SCRAMjet (1)

AnarchoFreak_00 (126755) | about 13 years ago | (#2229097)

Yeah... Now you kow what they call it a SCRAMjet don't ya now.
'Cause if one of those things came strait for you at 8570km/h, you'd better...SCRAM!

Ah well, It sounded alot funnier before I typed it.

great idea (1)

mj6798 (514047) | about 13 years ago | (#2229107)

This will make countries even more trigger happy, since they have even less time to react to an incoming missile.

Re:great idea (1)

nichughes (321642) | about 13 years ago | (#2229215)

The Russians are way ahead of you there. Allegedly.


New Scientist [newscientist.com] had an article on it some time ago.


--

Nic

The numbers don't make sense... (1)

XaXXon (202882) | about 13 years ago | (#2229108)

According to the article, the scramjet projectile was fired from a cannon at ~5400 MPH. From what I can gather, that much was done without any power from the scramjet system. At that initial velocity, 5400 MPH = 7920 FPS, it would cover the 260 feet in ~30 milliseconds, the total flight time of the projectile, according to the article. I'm not going to do the physics calculations, but I'm going to assume that in .03 seconds, wind resistance isn't going to have much affect on the velocity of the projectile, so what did the scramjet do?

Re: My first post doesn't make sense... (1)

XaXXon (202882) | about 13 years ago | (#2229122)

Oops, sorry. I can read, though my original post wouldn't show that.. Let me toss some more numbers here, hopefully ones that aren't listed in the original post..

From 5406 => 5909 MPH is a change of 503 MPH, or ~738 FPS. Doing this in .03 seconds gives an acceleration of 24,591 FPS^2. Dividing by 32 FPS^2 (the force of gravity) gives an average acceleration of 768.5 Gs over the flight of the scramjet. Not that anyone else couldn't figure this out, I just figured I'd do the calculation for you, and maybe make up for my earlier post...

Lets aim it at... (0, Troll)

VC (89143) | about 13 years ago | (#2229159)

Microsoft.

Auroura (2)

Perdo (151843) | about 13 years ago | (#2229178)

What makes this any different from a base bleed boat tail artillary shell? Again DARPA misses the mark. And if the Auroura is not a scramjet, what is it? This test is smoke and mirrors.

Re:Auroura (2)

Barbarian (9467) | about 13 years ago | (#2229193)

<i>What makes this any different from a base bleed boat tail artillary shell? Again DARPA misses the mark. And if the Auroura is not a scramjet, what is it? This test is smoke and mirrors.</i>

Well, this one carries fuel.

Re:Auroura (2, Informative)

dingbat_hp (98241) | about 13 years ago | (#2229318)

Well, this one carries fuel.

To some extent, so does a base-bleed shell.

Logistically, shells should be square-ended. You get more bang into the the chamber that way.

Aerodynamically, shells should be pointed at both ends, or in fact, even more pointed at the tail. The trouble with this is that it loses useful volume - although it's commonly done with small arms. The trick with base-bleed is that by burning a slow propellant in the tail of the shell, a high pressure gas plume is generated that makes the shell appear to be long-tailed, aerodynamically. You get the same compact shell layout (although you lose some space for propellant) and you get a long-range shell.

There are also rocket assist shells, but these are rare - they didn't work too well. They have some uses for heavy calibres with low muzzle velocities, but they lose in accuracy what they gained in range.

Acceleration (1)

dingbat_hp (98241) | about 13 years ago | (#2229309)

What makes this any different from a base bleed boat tail artillary shell?

It still accelerates after it has left the tube.

Secondly, WTF is a "base bleed boat tail" shell ? I've never seen anything (certainly not South African) that used both base-bleed and any boat-tailing together. Why would you ? If you use base-bleed you need the volume of a blunt-end, but you don't need the shaping.

Maybe it's just some 'Merkin deer-huntin' round...

Imagine... (0, Redundant)

szcx (81006) | about 13 years ago | (#2229185)

... a Beowolf cluster of ScramJets!

I liked slashdot's end-of-page quote... (1)

Sabriel (134364) | about 13 years ago | (#2229190)

"Baby on board".

Hope it was wearing a seatbelt. :)

30 milliseconds? (1)

mshiltonj (220311) | about 13 years ago | (#2229191)

The scramjet's engines then ignited, and the object moved another 260 feet, in just 30 milliseconds, before it came to rest in a series of steel plates designed to halt the flight.


I can juggle for 30 milliseconds.


I can ride a unicyle for 30 milliseconds.


I'm as big a technophile as the next guy, but this smells like an $800k proof-of-concept, engineered to be a PR success?


Too bad there aren't any accompanying pictures, but with a flight time of less than a second, I guess they'd be hard to get.

Re:30 milliseconds? (1)

Chris Hind (176717) | about 13 years ago | (#2229236)

I can juggle for 30 milliseconds.

I can ride a unicyle for 30 milliseconds.
Yes, but can you get a scramjet to ignite for 30 milliseconds? These guys can.

Re:30 milliseconds? (1)

pausz (218832) | about 13 years ago | (#2229255)

At $800 000, someone MUST have taken pictures, and according to the article they did:

High-speed video and still cameras, as well as X-ray and infrared cameras, recorded the flights.


Perhaps those pictures are classified information. DARPA is picking up the tab.

Stupid Empirical units (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229229)

When, I say when, are you Americans gonna use proper SI units?

punched through a series of steel plates (1)

non (130182) | about 13 years ago | (#2229259)

can you say tank busting weapon? remember this is a projectile we're talking about, one thats only 4" in diameter. however the 130' cannon might be a liability on the battlefield.

<ramble>
on the aviation side, there have been rumors of hypersonic vehicles being tested at Area 51 for ten years now. as far as flying in one, i don't think acceleration to mach9 in less than a few mintues would be enjoyable to your average business passeneger.
</ramble>
[nasa.gov]
this article at NASA gives a better explanation and has some QuickTime movies of the X43A.

What "powered" device? (1)

abiogenesis (124320) | about 13 years ago | (#2229268)

>The Sacramento Bee is running this story about the
> first powered device to achieve "hypersonic"
> speeds in the Earth's atmosphere.

And I always thought current jet planes were "powered" too... It seems they aren't.

hmm, let's see (2)

K. (10774) | about 13 years ago | (#2229272)

ballistic missile defence network + scramjet
cruise missiles = a lot of very pissed-off
nuclear powers.

slash period! (-1, Offtopic)

Anonymous Coward | about 13 years ago | (#2229279)



e.x.c.u.s.e. m.y. p.o.s.t. i. a.m. h.a.v.i.n.g. m.y. p.e.r.i.o.d























The cannon is more interesting (3, Insightful)

redelm (54142) | about 13 years ago | (#2229285)

I can see how this short test worked, and how they can get some scramjet performace data in the 30 ms of free flight. Ain't microelectronics wonderful?

But frankly, I'm more interested in that super cannon. Mach 7.1 is 7,500 ft/s (2,300 m/s) which is extremely high. It would have a max range (neglecting aerodrag) of 300 miles! Did they use a gas-gun?

This will make my boss happy... (1)

elgen (22169) | about 13 years ago | (#2229286)

...Now I won't be late for work again :-)

Faster speeds... (1)

Mac Nazgul (196332) | about 13 years ago | (#2229306)

I was reading a research paper on scramjet technology, and according to their research it may be possible to scale these ships up to speeds of Mach 28.
That would mean be able to get anywhere in the world in less then 1/2 of an Hr.
That woud make for quite a plane ride- as other posters have said barely enough time for the stewardess to serve beverages. But think of the military potential- Near instant strike response. We could kill people and be back for dinner!

stupid question? (3, Insightful)

Marcus Brody (320463) | about 13 years ago | (#2229314)

From the article:


Scramjets, or supersonic combustion ramjets, burn hydrocarbon fuel but scoop oxygen out of the atmosphere to combust it....


...The Pentagon and National Aeronautics and Space Administration are both studying scramjet technology since it would allow missiles or spacecraft to travel longer distances and carry larger payloads than rockets.


I'm sure i'm missing something fundamental here, but where the hell are spacecrafts supposed to get the oxygen from?
I guess they must just mean using scramjet untill leaving the atmosphere, and then use onboard oxygen, but it is a little misleading

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