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First Ever Scramjet Reaches Mach 10

Zonk posted more than 6 years ago | from the really-super-very-short-take-off-and-landing-or-rsvstol dept.

Space 235

stjobe writes with the news that a group of US and Australian scientists successfully tested a supersonic scramjet engine in the Australian Outback on Friday. The Sydney Morning Herald reports that a rocket carrying the engine reached mach 10, and climbed to an altitude of 330 miles before the apparatus re-entered the Earth's atmosphere. "Australia's Defense Science and Technology Organization (DSTO) said it was believed to be the first time a scramjet had been ignited within the Earth's atmosphere ... Scramjets are supersonic combustion engines that use oxygen from the atmosphere for fuel, making them lighter and faster than fuel carrying rockets. Scientists hope that one day a scramjet aircraft fired into space could cut traveling time from Sydney to London to as little as two hours."

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235 comments

X-43A? (5, Informative)

Chairboy (88841) | more than 6 years ago | (#19529393)

What about the X-43A? It also ignited successfully and flew under power.

http://en.wikipedia.org/wiki/Boeing_X-43 [wikipedia.org]

This is cool, yes, but the emphasis on "first" seems a bit off.

Re:X-43A? (5, Funny)

evil_neanderthal (1024405) | more than 6 years ago | (#19529635)

mach 10? not fast enough! i want one for my microwave! faster pizza bagles! faster ezmac! faster! can i mount one to my pelvis! can't wait to see what the missus thinks. miss. mistress! huh? i need a gun that shoots scramjets with knives on the end! can we start calling it warp 10 instead of mach 10? they should have taped a dvd to it to set a data transfer record! we need a new unit for that! dvd-mph! gigafoot-hertz! i want the 13 gfhz model for my toaster! butter the whole toaster so it doesn't get incinerated from air friction! does it come with internet? i want one with internet! it needs bluetooth! eeeeeeee

Re:X-43A? (4, Insightful)

tbischel (862773) | more than 6 years ago | (#19529837)

...it was believed to be the first time a scramjet had been ignited within the Earth's atmosphere
Ah I see... as opposed to the many airbreathing scramjets ignited outside earths atmosphere.

Re:X-43A? (1)

arcenal (1116213) | more than 6 years ago | (#19529907)

While this engine isn't first, the x-43 wasn't first either. HyShot was the first also made by these guys. Perhaps this engine was using a different fuel than the earlier engines but the reporter just went for an easy "WORLD FIRST SCRAMJET" headline?

HyShot, HyCAUSE and HiFire (5, Informative)

Anonymous Coward | more than 6 years ago | (#19530095)

It was the same fuel as HyShot [wikipedia.org] , plain old hydrogen (plus oxygen gathered from the atmosphere). This scramjet project was named HyCAUSE and the engine was physically a fair bit larger than the successful HyShot flights by the same team a few years back. The team originated from the University of Queensland moved to the Defence Science and Technology Organisation about a year ago. The next flights are a series of ten over five years under the name "HiFire".

Re:X-43A? (3, Insightful)

Gorshkov (932507) | more than 6 years ago | (#19529947)

From my quick reading of the wiki on the X-43A you linked to, I get the impression that it only it it's scramjet at about 100,000 feet .... but TFA states that this was the first to ignite and operate it's scramjet *within the atmosphere*. I'd guess that's the difference.

100,000 feet is well within the atmosphere (4, Informative)

Anonymous Coward | more than 6 years ago | (#19530313)

According to wikipedia, (I know), the atmosphere is usually considered to end at 328,000ft. (Karman line)

The Stratosphere goes to 160,000ft. You have to go above 50 miles (264,000ft) to be considered an astronaut, and atmospheric effects are noticeable at 400,000ft during reentry.

Re:100,000 feet is well within the atmosphere (1)

Gorshkov (932507) | more than 6 years ago | (#19530619)

gotcha .... I stand corrected. I gotta learn to NOT post at 4am ..... it's causing a lot of pissyness in the global warming article just down the hall :-)

Re:X-43A? (1)

Moskit (32486) | more than 6 years ago | (#19530103)

Australians were the first to launch scramjet, although a few years ago.
Quote from the wikipedia:

The X-43A's successful second flight made it the fastest free flying air-breathing aircraft in the world, though it was preceded by an Australian HyShot as the first operating scramjet engine flight.
(emphasis mine)

Re:X-43A? (1)

pipingguy (566974) | more than 6 years ago | (#19530131)

Eff that, I'm more worried about what kind of impact this new technology might possibly have on global climate change.

"First ever scramjet" ...? (2, Informative)

pushing-robot (1037830) | more than 6 years ago | (#19529403)

From TFA: "Australia's Defence Science and Technology Organisation (DSTO) said it was believed to be the first time a scramjet had been ignited within the Earth's atmosphere."

http://en.wikipedia.org/wiki/Hyper-X [wikipedia.org]

Is there something I'm just not getting here?

Re:"First ever scramjet" ...? (0)

QuantumG (50515) | more than 6 years ago | (#19530367)

Other than the fact that scramjets have been under research for longer than fusion now and will continue to be forever because they're really interesting research topics and make for great research papers, but are mostly an enigma that we're unlikely to solve anytime soon.

OK but... (1)

phantomcircuit (938963) | more than 6 years ago | (#19529419)

While that is VERY cool, this particular design is mroe of a technical demonstration than an engine that could propel an aircraft.

So while this is a big step forward, it isn't as big as it seems.

Altitude of 330 miles??? (1)

niktemadur (793971) | more than 6 years ago | (#19529427)

Holy cow, this thing can achieve Earth orbit! So why focus just on the Sydney-London thing (or to use that ol' "New Orient Express" analogy, New York-Honk Kong) instead of cheap space travel?

Re:Altitude of 330 miles??? (4, Informative)

Rei (128717) | more than 6 years ago | (#19529503)

Holy cow, no it can't! Not only isn't it going nearly fast enough, but the vast majority of that delta-V came from a conventional rocket. The scramjet experiment only operated for 14 seconds [theage.com.au] .

This is an experiment. Scramjets are still in the "data-gathering" phase, not the "let's make a realistic engine" phase, nor the "let's make a scramjet-powered craft" phase.

Re:Altitude of 330 miles??? (2, Informative)

Lisandro (799651) | more than 6 years ago | (#19529675)

Holy cow, no it can't! Not only isn't it going nearly fast enough, but the vast majority of that delta-V came from a conventional rocket.

Not only that, scramjets need an additional propulsion system in order to reach working speeds. Usually, yes, conventional rockets [wikipedia.org] are used. This is one of the major drawbacks in these type of designs.

Just ask CIA/Skunk works, area51 (1)

cheekyboy (598084) | more than 6 years ago | (#19529813)

I am sure the skunk works at CIA/Boeing have all the data/results/secrets already.

Hell, they made the SR71 back in the old days, imagine what they have NOW!!!

They wont say ever!!! Stupid top secret morons, showing it off will not hamper anything. I bet Boeing just wants to make another $500billion to $1500 billion selling conventional aircraft for
the next 25 years, then they will bring online the new models later.

Good article at http://www.americanantigravity.com/documents/NASA- TM-2006-214547.pdf [americanantigravity.com]

"NASA Memorandum on Advanced Propulsion
by R.L. Sackheim, J.W. Cole, and R.J. Litchford (NASA MSFC)
Where is U.S. space flight today, and how did we get here? After 40 years, why are we slowly converging on a slightly updated Apollo architecture? Why is there no Moore's law analogy for rocketry?
Clearly, we have arrived at a watershed moment in space flight history, and it is essential that we reflect on such questions in a forthright way. Decisions are now being made that could set our future course in space for decades to come, and it is appropriate that we examine the logic that brought space transportation full circle almost back to where we started."

Re:Just ask CIA/Skunk works, area51 (2, Informative)

deopmix (965178) | more than 6 years ago | (#19530011)

I really do hate to nitpick, but the skunk-works are Lockheed Martin, not Boeing.

Re:Just ask CIA/Skunk works, area51 (2, Insightful)

Keys1337 (1002612) | more than 6 years ago | (#19530063)

I'm sure they could develope some insane passenger aircraft, but they need to make money not bleed it. If I came up with a proposal to build basically the concord on steroids I don't think people would buy it. I'd try to sell them more cost effective and reliable planes since that's what they are buying.

Re:Altitude of 330 miles??? (1)

cheater512 (783349) | more than 6 years ago | (#19529917)

When you say 'most' your saying that the conventional rocket got it to 51% or higher of its speed?
A Mach 5 conventional rocket? Cool!

Re:Altitude of 330 miles??? (2, Interesting)

MikShapi (681808) | more than 6 years ago | (#19530247)

You seem to be sharing the common misconception that LEO altitudes and above cannot be reached at low speeds.

Dude, you can reach an altitude of 330 miles just fine with a perfectly low speed. There's nothing unphysical about it that requires the invocation of holy cows. It is also true that with the lack of a *horizontal* velocity of about mach 30 (at ~100km, you'd need less if you get as far as 330 miles high), you fall back down (well, not back to the same place, you may have traveled halfway around the world by then, but still, back *down*) like a rock. This is what spaceship-1 did, this is what this experiment did. This is what ICBM's do. This is even what proposed "2-hour-sydney-to-london" flights will do. Speed is only needed to get into low orbit.
They go high, fast enough to stay in space for the duration of cruising their trajectory, without air resistance and at pretty dang fast speed, then they just drop back into the atmpsphere.

Nothing to get overly excited about. The concept was already proven to work, and we haven't reached a point where the technology is generating value yet, so it's all still technological limbo. Not that it wouldn't be nice if it actually got done after 20 years of R&D. Shorter times for less fuel would pro'lly mean many more flights in lifetime of aircraft, less fuel burned, less time-in-air per trip, more in-range accessible destination for carriers and while I haven't the slightest clue as to what operational costs on scramjet-based planes would look like, it would seem to have the potential to cheapen things from where they are today.

Bzzzt. Wrong! (5, Informative)

tritone (189506) | more than 6 years ago | (#19529475)

"scramjets are supersonic combustion engines that use oxygen from the atmosphere for fuel"

Scamjets use oxygen from the atmosphere as an oxydizer unlike traditional rocket engines which need to carry their oxydizer. Scramjets still need to carry fuel.

No. I am not a rocket scintist.

Re:Bzzzt. Wrong! (0)

AaronLawrence (600990) | more than 6 years ago | (#19529495)

Yes, makes a "small" difference doesn't it. The difference between saying "I made a better engine" and perpetual motion.
But who cares about these tiny details.

Re:Bzzzt. Wrong! (1, Insightful)

Anonymous Coward | more than 6 years ago | (#19529609)

Bzzzt. Wrong! Using oxygen as a fuel would just mean the engine has a very large fuel supply in which it is immersed. Really handy, but nothing perpetual about it.

Re:Bzzzt. Wrong! (1, Funny)

Anonymous Coward | more than 6 years ago | (#19529791)

Bzzzt. GAY!

Re:Bzzzt. Wrong! (1, Informative)

Anonymous Coward | more than 6 years ago | (#19529685)

True, but conventional rocket engines are hydrogen + oxygen = water. But oxygen is a lot heavier than hydrogen, what with all of those extra protons, so it makes up most of the fuel. A scramjet, by weight, only needs a fraction of the fuel of a conventional rocket.

Re:Bzzzt. Wrong! (1)

khallow (566160) | more than 6 years ago | (#19529741)

Oxygen is not a fuel. It is an oxidizer. The word you're looking for is "propellant" not "fuel".

Re:Bzzzt. Wrong! (1)

Teun (17872) | more than 6 years ago | (#19530073)

You are very right.
And just as curious is the statement that it was the first time a scramjet had been ignited within the Earth's atmosphere, because by design a scramjet doesn't carry it's own Oxygen the atmosphere is the only place it can ignite.
All together a rather sad summary of a nice engineering feat.

Not for me (1)

stinerman (812158) | more than 6 years ago | (#19529525)

I don't know about traveling that fast. If you do it enough the time dilation might make it that my friends and family would die a few seconds sooner (relative to me of course).

</sarcasm>

Why was the altitude changed? (5, Insightful)

thesolo (131008) | more than 6 years ago | (#19529527)

This event took place in Australia, and was reported by an Australian paper; therefore, it was correctly reported in the metric altitude of 530 kilometres.

So why was the summary changed by slashdot editors to the imperial unit?

Firstly, not everyone who reads this site is American, and secondly, this is an audience of nerds. I think we can handle kilometres! Even the USA's NASA is all metric now.

The scientists who developed this scramjet used metric, the country it was tested in used metric, the newspaper that reported it used metric, so how about we keep it that way?

Re:Why was the altitude changed? (1)

Cheezymadman (1083175) | more than 6 years ago | (#19529553)

Because the metric system is complicated and scary. Like Linux, or pick-up instead of delivery.

Re:Why was the altitude changed? (2, Insightful)

Anonymous Coward | more than 6 years ago | (#19529567)

Don't forget, this was the country that elected George Bush. They're only comfortable with simple things, thinking confuses them.

Re:Why was the altitude changed? (4, Funny)

drgonzo59 (747139) | more than 6 years ago | (#19529637)

And besides we all know that God uses the imperial system and only communists use metric...Hail Bush!

Re:Why was the altitude changed? (0)

earlymon (1116185) | more than 6 years ago | (#19529649)

uh, maybe because a good many of us learned that 62 miles meant space, that Yuri Gagarin orbited above 180 miles, that Friendship 7 made a 120 miles, and that until we're talking parsecs, it's all just noise?

Re:Why was the altitude changed? (0, Troll)

timmarhy (659436) | more than 6 years ago | (#19529785)

do you have a fucking point? learn metric you backwards country

Re:Why was the altitude changed? (0, Offtopic)

Gryle (933382) | more than 6 years ago | (#19529925)

do you have a fucking point? learn metric you backwards country
We'll learn the metric system when you learn the proper rules of capitalization and punctuation. Do we have a deal? :)

Re:Why was the altitude changed? (5, Insightful)

Anonymous Coward | more than 6 years ago | (#19530147)

England invented proper rules of capitalization and punctuation, and they officially use the metric system now. Is there any country other than the US which doesn't? (According to Wikipedia two other countries actually do; Liberia and Myanmar. Great company.)
Not to mention that the US has been butchering proper English spelling and grammar ever since Webster. Just switch to Metric measurements and the Celsius temperature scale already. The rest of the world is getting tired of having to convert measurements for the sole purposes of dealing with the US. [/troll]

Re:Why was the altitude changed? (1)

earlymon (1116185) | more than 6 years ago | (#19529929)

do you have a fucking point?

no, other than that maybe quibbling over units of measure accomplishes nothing, and that the real measure of the accomplishment is not diminished by a conversion factor. i didn't fully realize that there could be a real reaon for the complaint over the change from km to mi other than the guy having a bad day. what one system accompishes over another is meaningless for some of us that have worked space-based systems - conversion tends to be a rather automatic process when you think globally.

learn metric you backwards country

and perhaps i'll learn to be less subtle as well - thanks!

btw- thanks for the promotion to country; fortunately, it won't require me to buy larger asbestos underoos

ps - you misspelled Système International d'Unités (SI) base units as metric - are we all happy now?

Only old farts, MAINSTREAM idiots use MILES (3, Insightful)

cheekyboy (598084) | more than 6 years ago | (#19529825)

Yeah nerds, learn KM, not Miles.

No self respecting scientist or nerd would ever use the word MILES in their own documents.

Slashdot is NOT mainstream, get back to being NERDY!!!

Re:Why was the altitude changed? (1)

rafaMEX (1111415) | more than 6 years ago | (#19529829)

thesolo , now you have replays saying the metric is more complicated lol, why 1 meter == 1,000 kilometer or 1,000 mm == 1 meter how is that more complicated ? lolz :P

Re:Why was the altitude changed? (0)

Anonymous Coward | more than 6 years ago | (#19529849)

What's even worse is that Americans don't even use Imperial units.
They use their own half baked system consisting of some of the same names, and completely different measurements that they have the audacity to call English. As if it were the Queen's fault or something.

Re:Why was the altitude changed? (1)

Gryle (933382) | more than 6 years ago | (#19529899)

Most Americans refer to it as measurement system as "Customary" or "Traditional" rather than "English".

Re:Why was the altitude changed? (1)

Fred Ferrigno (122319) | more than 6 years ago | (#19530323)

Really? Seems to me that most people don't have a name for it at all. It's not something commonly referenced, so I can't imagine any term that I'm confident would be interpreted correctly consistently. Normally you'd just say the specific unit you were talking about. "Is that in meters or feet and inches?" Also you might identify something in terms of not being metric.

Re:Why was the altitude changed? (1)

Down8 (223459) | more than 6 years ago | (#19530583)

Bad translation - "standard or metric?" is the question often asked....

-bZj

Re:Why was the altitude changed? (1)

cheater512 (783349) | more than 6 years ago | (#19529939)

Its a American website.

From my experiences they are very bad at converting anything.
Timezones, Metric -> Imperial, etc...

Re:Why was the altitude changed? (0)

Anonymous Coward | more than 6 years ago | (#19530111)

From my experiences they are very bad at converting anything.

If you're so superior at converting, convert the miles to kilometers in your head and you have nothing to complain about.

Personally, I convert just fine, and thus usually don't give it a passing thought when something is miles or kilometers.

While I prefer the kilometer for its conversion ability, it is naive to pretend that the mile is an eccentric unit. This is the internet, and we are speaking in English. A quick check of googlefight [googlefight.com] shows that "miles" is written 10 times more often than "kilometers". So use your intellect and convert.

Re:Why was the altitude changed? (0)

Anonymous Coward | more than 6 years ago | (#19530075)

Actually, NASA isn't all metric yet. Perhaps officially, they claim to be using metric, but internally, a lot of engineers are still using whatever they want. As a result, NASA uses a mix of imperial and SI units (and the nautical mile also, which isn't an official SI unit.)

Re:Why was the altitude changed? (2, Funny)

Chibi Merrow (226057) | more than 6 years ago | (#19530179)

So why was the summary changed by slashdot editors to the imperial unit?


Mostly just to piss people like you off.

Suborbital trajectories? (5, Interesting)

caseih (160668) | more than 6 years ago | (#19529545)

This is very interesting to read as I just finished reading Ben Rich's book "Skunk Works" where he talks about the SR71. When president Reagan announced the administration's intention to build a hypersonic airplane, he just shook his head. It's simply not practical, with or without the scramjet engine. The SR71 flew at 85,000 feet at about Mach 3.2, and reaches skin temperatures of 2000-3000 degrees (F I presume) just from moving through the atmosphere. Accelerating to Mach 10 would burn up or otherwise compromise any current building material, except for the carbon-carbon and ceramic materials used on the space shuttle's heat shield, but aren't practical for airplanes. So what good is this scramjet, at least as far as a hypersonic airplane goes? Seems to me all this talk of Sydney to London in 12 hours is a bit fanciful. So the question is, how exactly will this engine be used to accomplish this? The only way to reach hypersonic speeds without burning up is to make the trajectory sub-orbital so that the aircraft is in the thinnest atmosphere possible when it's firing it's engines to go Mach 10. But of course there's not a lot of oxygen at that altitude. And to really achieve sub-orbital trajectory you need a rocket engine, not any kind of air-breathing engine. So my questions are: Is Ben Rich right that hypersonic travel is essentially impossible? Will the scramjet help with a suborbital trajectory? I understand that igniting the scramjet is a breakthrough. Jet turbines at supersonic velocity have always been problematic.

Off-topic, Ben Rich says in his book that the codename Aurora that everyone likes to think refers to some hypersonic aircraft, was actually the codename placed on the B-2 project as Lockheed and Northrop were competing for the contract. It's funny to think that to this day, folks still hang onto this and imagine some mythical hypersonic airplane. Which never existed. Or does it?

Re:Suborbital trajectories? (1)

caseih (160668) | more than 6 years ago | (#19529559)

Ahem. Sydney to London in 2 hours.

Re:Suborbital trajectories? (2, Informative)

richdun (672214) | more than 6 years ago | (#19529615)

Technically speaking, yes, hypersonic travel will always be impossible, barring some super-material able to take the heat. The trick is that once you get out of the atmosphere, a term like "hypersonic" is nonsensical. The speed of sound in a vacuum approaches a theoretical infinity, so to reach it, let alone top it by a factor of 7 or more, would be nonsense (unless, of course, your name is Brannon Braga! *rimshot*)

Often, though, for simplicity sake, we use terms like "mach 10" to mean mach 10 at sea level or some other decently benchmarked altitude.

Re:Suborbital trajectories? (2, Interesting)

richdun (672214) | more than 6 years ago | (#19529645)

Er, it's the night for corrections - the speed of sound in a vacuum approaches a theoretical asymptote, not infinity. The speed of sound generally gets lower as the material loses density, higher as the material gains density (think about a wave traveling through a solid block, as opposed to one traveling through water, then one traveling through the air)

Re:Suborbital trajectories? (5, Insightful)

Rei (128717) | more than 6 years ago | (#19529623)

All of his points are basically correct in the present day. However, the most critical one -- the expense of heat-resistant materials -- may only be temporary. It's hard to say. Carbon fiber was once the "we'd love to use it, but it'd be too expensive except for pricey custom luxury jobs" material for airplanes. Now look at the Dreamliner -- a mass-produced majority-carbon-fiber giant by Boeing, which despite delays, companies have been snapping up.

I wouldn't rule out the concept of hypersonic travel just because heat resistant materials are expensive today. If the rest of the tech is there and is affordable, and there is sufficient demand... who knows? The airline industry is bloody huge and there is lots of money to be made by faster travel, so it could draw a lot of R&D money if the other tech looks good.

Re:Suborbital trajectories? (0)

Anonymous Coward | more than 6 years ago | (#19529839)

You could make it out of Unobtanium [wikipedia.org] .

Re:Suborbital trajectories? (1)

khallow (566160) | more than 6 years ago | (#19529861)

I think you ignore several things. First, I think regenerative cooling (using the fuel to absorb the excess heat) has progressed since the days of the SR71. So my take is leading edge surfaces will take a higher thermal load. Second, why not fly higher? I understand that thermal heating is still a problem at higher elevations merely because there's less atmosphere to transfer the heat to, but the less atmosphere there is, the less heat that your fuel needs to absorb. Finally, I figure the Shuttle is a demonstration that ceramics and similar materials can be used on an airplane. After all, that is what the Space Shuttle is (well, a crude glider) when it is reentering Earth's atmosphere.

Re:Suborbital trajectories? (0)

Anonymous Coward | more than 6 years ago | (#19529975)

Ceramic tiles?

Uh, Columbia much?

Why not just make plane out of O-rings FFS.

Military, not Civilian applications (4, Insightful)

moikka (1085403) | more than 6 years ago | (#19530185)

This is prime example of technology that has almost purely military applications.
However since that does not excite public positively, they are instead fooling the public talking about civilian use.
What might be possible some day is to deliver a bomb from Sydney to London in very short time. Not human passangers.
The inherent heat problems are about 100 times easier to solve, if you imagine
the payload is 50kg of plutonium instead of 5000 kg of humans.

Re:Military, not Civilian applications (3, Interesting)

moikka (1085403) | more than 6 years ago | (#19530361)

Also think about their primary selling-point,
capable of using oxygen from air and not having to carry it,
is only an advantage over rocket-engines.
Jet engines already use oxygen from the air.


In civilian travel there is great need for fuel-efficiency.
If their biggest problem is excess heat,
it automatically means they are wasting huge amounts of fuel to create that heat.
Only military can afford this wasted fuel.


Also there is a huge problem in take-off and landing from ground.
Ramjet is not going to work in those cases.
So for civilian aircraft use they are going to need conventional jet engines for that purpose.
Guess how aerodynamically efficient these extra jet engines are going to be at 10 Mach?
Also another problem that does not exist in military use.


So 100% certainty the only application this is going to have is delivering bombs.

Re:Suborbital trajectories? (0)

Anonymous Coward | more than 6 years ago | (#19530271)

NASA investigates scramjets for the same reasons they do all their other basic research: the hope that future projects will be based on knowledge learned, whether those projects are foreseeable or not.

ICBM (0)

Anonymous Coward | more than 6 years ago | (#19529565)

ScrambleJet = ICBM
Nothing like a dinkum Aussie WoMD.
Aussies are evil !!!

Obligitory Spinal Tap joke: (1)

rts008 (812749) | more than 6 years ago | (#19529673)

Sooo...it only goes to 10.

This one goes to 11!

Okay, now my funny bone has been buried....

Kudos to these people. It may have only been for some seconds, but at least they are forging onward, and I salute their work!

Proving theory is usually no easy task, a working prototype seems to be 3/4 of the battle.

Seriously, hat's off!!!

330 miles is well beyond the Kármán line (4, Informative)

eyebits (649032) | more than 6 years ago | (#19529789)

330 miles is approximately 5 times the minimum altitude for entry into "space." The Kármán line is at an altitude of 62 miles (100 km) which is the boundary that defines where space begins. 75 miles is where atmospheric drag starts to have an effect. This means the craft traveled well into the Thermosphere. People who travel above 50 miles are called astronauts by NASA.

Re:330 miles is well beyond the Kármán l (1)

GISGEOLOGYGEEK (708023) | more than 6 years ago | (#19530337)

Significant atmostpheric drag occurs AT much hiGHer elevaTIonS. To say that it starts to have an effect at 75 miles is nuts.

tHE International space station constantly looSEs eleVATion dUe to atmostpheric drag, it's usual elevation is around 500 miles. When the space shuttle visits, it usually burns its rockets to push the ISS back to an elevation close to that.

Just last year the ISS was in a very low orbit becuase solar storms had caused the upper atmosphere to bulge, placing more drag on the station.

(my keyboard is failing, sorry about the mixed case words)

Mach unit valid in space? (1)

Gabrill (556503) | more than 6 years ago | (#19529803)

engine reached mach 10, and climbed to an altitude of 330 miles before the apparatus re-entered the Earth's atmosphere.
Does it bother anyone else that they're using the speed of sound IN THE ATMOSPHERE to measure a speed of a vehicle NOT IN THE ATMOSPHERE? Or is the summary just misleading?

Re:Mach unit valid in space? (1)

Semptimilius (917640) | more than 6 years ago | (#19529873)

I don't think it really matters. It's only a reference speed (probably established at a specific set of atmospheric parameters). They could have referenced it against the speed of light, km/h.

Re:Mach unit valid in space? (0)

Anonymous Coward | more than 6 years ago | (#19529965)

Yes, it's still valid. This is barely beyond the edge of Earth's atmosphere, and as such is still in a non-vacuum. Now, the density is VERY low, but there's still enough gas to determine a Mach number. I'm willing to bet that the Mach number was WAY over 10, and that they're referencing it to sea level, or some other low altitude reference frame.

And yes, I AM a rocket scientist, I do know what I'm talking about here.

Re:Mach unit valid in space? (0)

Anonymous Coward | more than 6 years ago | (#19529969)

It's roughly 330-ish m/s, so it's a rather good measure of speed because it's well known and easy to imagine.

Re:Mach unit valid in space? (1)

CompMD (522020) | more than 6 years ago | (#19529991)

Mach number is variable. It depends upon temperature and is only valid in a fluid environment, not a vacuum. You can't have "Mach 10" at 330 miles.

I'm not an aerospace engineer, but I do play one at work.

Re:Mach unit valid in space? (1)

evilsofa (947078) | more than 6 years ago | (#19530055)

Because atmospheric drag is still an issue at 330 miles up. They used Mach number, not the speed of sound. Mach numbers are extremely important when talking about hypersonic speeds in atmosphere.

Look up the wiki articles on "Mach Number" and "Earth's atmosphere" for more info.

Re:Mach unit valid in space? (1)

Woek (161635) | more than 6 years ago | (#19530081)

I guess it first reached Mach 10 in the atmosphere, and then exited it. A scramjet engine does not work outside of the atmosphere, but it shows that it can give the craft a big impulse. Going Mach 10 in the upper atmosphere doesn't require a lot of thrust; the density is so low that there is relatively little drag. The trick is that an airbreathing engine with a supersonic combustion chamber needs to fully mix AND combust its fuel in one or two milliseconds to use its fuel efficiently.

Re:Relativity in a Dark Place (4, Funny)

craznar (710808) | more than 6 years ago | (#19530173)

As the theory of relativity breaks down when someone switches the lights off - as C becomes ZERO.

Oh no ...Einstein didn't think of that.

Lets not get too excited (1)

HarryCallahan (673707) | more than 6 years ago | (#19529903)

"They said it (the rocket) reached an altitude of 530 kilometres (330 miles) before the scramjet was successfully deployed following re-entry to the Earth's atmosphere."

From my reading the conventional rocket took the scramjet to 530 km and then the scramjet fired up on the way down, you have to assume somewhere much closer to the earth where oxygen is available

The mach 10 and 530km height was attained by the mother rocket, the scramjet just lit up for a bit.

That's all well and good, but... (1)

plaxion (98397) | more than 6 years ago | (#19530017)

does it run Linux?

/obligatory

Re:That's all well and good, but... (0)

Anonymous Coward | more than 6 years ago | (#19530119)

Imagine a beowulf cluster of these. . .

SCRAM has been done, The real trick will be ... (3, Insightful)

WindBourne (631190) | more than 6 years ago | (#19530155)

getting these to fly without using a rocket to start it. If we can get it to start from say a mach 2 or better sub sonic mach .9, then this will be feasable for more than just bombs. As it is, the only place that this will be of use is in intercontental bombs (small and cheaper).

2 hours (5, Funny)

Anonymous Coward | more than 6 years ago | (#19530277)

Including airport queues that's only about 5 or 6 hours.

Aurora? (0)

Anonymous Coward | more than 6 years ago | (#19530375)

What about the Aurora [rapidshare.com] ?

Supersonic scramjet? (0)

Anonymous Coward | more than 6 years ago | (#19530557)

That's supersonic supersonic cramjet, twice as supersonic as a usual cramjet. Quite cool.
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