First Ever Scramjet Reaches Mach 10

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."

Why was the altitude changed?

[thesolo]

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?

[Anonymous Coward]

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

Re:Bzzzt. Wrong!

[Anonymous Coward]

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:Suborbital trajectories?

[Rei]

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.

Only old farts, MAINSTREAM idiots use MILES

[cheekyboy]

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:X-43A?

[tbischel]

...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?

[Gorshkov]

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.

Re:Just ask CIA/Skunk works, area51

[Keys1337]

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:Why was the altitude changed?

[Anonymous Coward]

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]

SCRAM has been done, The real trick will be ...

[WindBourne]

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).

Military, not Civilian applications

[moikka]

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.

330 miles ?

[Yvanhoe]

How is an altitude of 330 miles within earth's atmosphere ?

Re:Altitude of 330 miles???

[dbIII]

Not that it wouldn't be nice if it actually got done after 20 years of R&D.

Oddly enough I was looking at a scramjet model at around this time in 1987. Subsequent revisions used less fuel and had other advantages - but while it's relatively cheap to do computer modelling and to build a shock tunnel to test these things at mach 8 on the ground it costs a lot to launch a rocket to get the higher speeds. It's not that surprising that it has taken over 20 years on a shoesting budget in a relatively small engineering department in Australia to get this far and get moved to a better funded organisation.

Faster is better

[Anonymous Coward]

... all the better to bomb you with.

Actually, it could be done

[Moraelin]

Actually, at least theoretically a scramjet would continue to accelerate as long as you have air and fuel. You have enough air you have of that ascent (after that you have the speed anyway), and fuel you'd carry anyway. A rocket carries its fuel too.

That's actually one thing that makes scramjets tempting: the fact that it doesn't cap lower than that orbital velocity, and it can work with rather thin atmosphere too. So if you can go upwards at all with it, and modify the trajectory to have enough air for more of the time, you can eventually get it to stay up there.

Probably the only thing that _might_ change, if your scramjet doesn't get enough acceleration, is that you shoot it closer to the horizontal than upwards. Well, normal rockets don't really go vertically either. As you've said, they have to end up with that mach 30 horizontal speed. The difference would be that the rocket starts closer to vertical, to clear the dense atmosphere as fast as possible, and bends later, while probably a scramjet would start directly oblique, to make the most of that atmosphere.

Of course, when experimenting to just get the thing sorted out at all, there's somewhat less point in aiming directly for LEO. So probably 14 seconds are enough for experimental purposes.

Also, well, while scramjets are still experimental, ordinary ramjets aren't. A heck of a lot of missiles already use ramjets. E.g., IIRC the Russians were the first to use them on anti-aircraft missiles, but in the meantime almost everyone else does.

So technically we'd already have a pretty damn fast engine to put on an aircraft. If anyone wanted to make a Mach 5 passenger aircraft, that's probably already feasible with ramjets. The reasons why we don't are completely different, and IMHO somewhat unlikely to change because of scramjets.