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July 24, 2009 10:25 AM   Subscribe


 
I believe it was the comedian Robert Townsend who said (in the 80s) "Don't you be talkin' 'bout cocaine lest you got some!"

I feel the same way about Scramjets.
posted by MarshallPoe at 10:57 AM on July 24, 2009


I like how the headline is "Scramjets are go" but the actual article is about how they aren't quite there yet. I'm sure this wasn't a deliberate lie designed to sell copy.
posted by DU at 10:58 AM on July 24, 2009 [2 favorites]


F.A.B.
posted by yoink at 10:59 AM on July 24, 2009 [1 favorite]


Actually NASA Tested a scramjet based plane a couple of years ago. It didn't carry any passengers, or anything though.
posted by delmoi at 11:00 AM on July 24, 2009


Go X-51A! I cheered for HyShot, I worked at LaRC during the X-43A project, and I sincerely hope that scramjet technology finally matures. However, I can't help but notice that the cover of the July 2009 issue of New Scientist is strikingly similar to the cover of the May 1986 issue of Popular Science.
posted by rlk at 11:03 AM on July 24, 2009 [3 favorites]


X-43A Raises the Bar to Mach 9.6

9.6 << 25
posted by DU at 11:04 AM on July 24, 2009 [1 favorite]


Anything can happen in the next half century!
posted by Artw at 11:05 AM on July 24, 2009


If by go you mean, it's highly experiemental and we've yet been able to go hypersonic without losing the vehicle, then yes, we're go.

That said, I've gotta run-- I'll just step into my teleportation device, so I can materialise in my flying car, before I drop down the wormhole on the way to pick up a KFC in Alpha Centuri which I use my micropayments to purchase.

The future is now!
posted by Static Vagabond at 11:09 AM on July 24, 2009


Considering that Boeing can't even get their Dreamliner jet off the ground, I don't think there's much of a market for something that not only consumes vast amounts of fuel, but requires two (!) separate engine systems, three if you want to reach orbit.

This is cool technology, in the same way that nuclear rockets are cool.
posted by geoff. at 11:12 AM on July 24, 2009


You don't necessarily need two totally different propulsion systems. The SR-71 has a sort of hybrid engine - it's configured for sub-/transonic flight up to around Mach 1 and then some bits and pieces move around to bypass more air into the ramjet part of the engine. So you could do something similar for a hypothetical scramjet that doesn't have a tendency to destroy itself.

Besides, we have several vehicles that require two separate engine systems. SpaceShipOne requires two separate vehicles to get into space. The Space Shuttle has three - two boosters and the engines on the launch vehicle itself.

I did a very brief amount of research about this stuff a couple months ago because of a totally out-of-the-blue question from a coworker - "Can I use a ramjet to get sustained speeds of Mach 5 or greater?" (I still have no idea why he needed this information, but I'm probably not privy to the reason anyway.) The coolest thing I found: presenting, the ramrocket. (Does that sound like an awesome vibrator to you?)

Anyway, off the top of my head you could might be able to use something like a ramrocket in front of a scramjet - rocket exhaust is supersonic due to the nature of rockets, so you can duct some extra air in with the exhaust to get some oxygen in to the scramjet inlet at supersonic speeds. Then you've got to deal with the extreme temperatures at the inlet as well as the outlet, but... like I said, this is off the cuff.
posted by backseatpilot at 11:23 AM on July 24, 2009


I can't help but notice that the cover of the July 2009 issue of New Scientist is strikingly similar to the cover of the May 1986 issue of Popular Science.

Heh. I actually thought of this nuclear ramjet cruise missile cover from Air & Space Magazine.
posted by Artw at 11:25 AM on July 24, 2009


Ha, and those Australian scramjets experiments are simply awesome - what better way to test an expensive piece of high technology by lofting it into the atmosphere and dropping it into the ground!
posted by backseatpilot at 11:28 AM on July 24, 2009


Their potential reusability has led to the tantalising idea that winged spacecraft could, in time, be much cheaper to operate than ballistic throwaways. They could even use the same facilities as commercial airliners, opening up space travel to commerce and even tourism.

Is there any real advantage to having space travel as an option in the private sector? Other than space tourism and scientific experiments there don't seem to be many practical applications for space flight.
posted by burnmp3s at 11:42 AM on July 24, 2009


Other than space tourism and scientific experiments there don't seem to be many practical applications for space flight.

I think there is a world market for maybe 5 rockets.
posted by DU at 11:44 AM on July 24, 2009 [12 favorites]


there don't seem to be many practical applications for space flight.

Let's take away your GPS, satellite phone, television, international communications, XM radio, Google Earth, and weather forecasting. Now ask the question again.
posted by backseatpilot at 11:47 AM on July 24, 2009 [4 favorites]


If we ever get reliable space travel, it will allow us to colonize the moon. It seems impractical, sure, but there are no pesky environmentalists (or environment, for that matter!) to get in the way of development.

Getting the first few probes up there and mining the crystals might be tough, but then we can start warping in Gateways, and we're good to go.
posted by explosion at 11:53 AM on July 24, 2009


I would think there would be a small but nonzero market for very fast suborbital transport. But then again, there apparently wasn't a sufficient market to sustain the Concorde, so who knows.
posted by hattifattener at 11:55 AM on July 24, 2009


I think there is a world market for maybe 5 rockets.

And IBM was correct... right up until the opening of Bouncee's Zero-G Brothel, and then aerospace boomed :-)
posted by -harlequin- at 12:03 PM on July 24, 2009


No, that GPS and whatnot all stem from developments we made in accomplishing a goal; in terms of applications of space flight, the practical ones (and "practical" is the key word) tend to be not as populous as one might otherwise imagine.

Humans are ridiculously needy. Don't freeze us, don't overheat us, don't expose us to massive amounts of cosmic rays, we need some acceleration over long periods of time, but not too much, or our little bones will snap. Feed us, water us. We need oxygen, in the right amount and pressure. No carbon monoxide, please. We're borrrred; are we there yet? We need space to stretch out in, or we might go crazy and murder one another.

What we need to proceed us, if space is to be anything more than an egoistic "we did it!" jaunt, are waves of autonomous, goal-directed robots to manufacture bases for us in gravity wells and harvest metal-rich asteroids to build the Big Frikkin' Metal Boxes we'd need to move around the solar system without getting cancer on our way to Neptune.

Mining planets? No elements exist on other planets that the energy costs getting them back to Earth wouldn't outweigh their value. Strange compounds, the likes of which we have never seen, whose properties might be miraculous? Welcome to the Amazon, welcome to the deep sea. Buck for buck, we'd get more interesting medicine out of the Amazon than we would out of Mars.

The spinoff technologies we originally received are great, but we are not likely to get any new ones if we're doing the same old thing, which is finding some exceptionally tolerant and trainable apes to stuff in a tin can and chuck across space. If we want new spinoff technologies, we'll need a new approach to space.

I don't see that happening.
posted by adipocere at 12:25 PM on July 24, 2009 [1 favorite]


He3 mining... ON THE MOON!
posted by Artw at 12:30 PM on July 24, 2009


No, that GPS and whatnot all stem from developments we made in accomplishing a goal;

I don't think you can really make that distinction. If the world stopped building space vehicles, we would quite rapidly (ie a handful of years) start to lose GPS and communications. While these systems do not always need manned spaceflight to maintain, they do require constant spaceflight.

in terms of applications of space flight, the practical ones (and "practical" is the key word) tend to be not as populous as one might otherwise imagine.

Another is that whole preservation of the species and civilization. The next mass extinction event is highly unlikely to be soon, but in a sense it's not unlikely to not be soon either - they don't happen often, but they're just plain random. The odds are unthinkably low but the stakes are unthinkably high. How do you balance that risk? I don't know. But I've put a fair share of my life into contributing to this civilization, which I quite like, and I'd prefer that some rock not wipe the whole thing off the face of the universe :-)
posted by -harlequin- at 12:45 PM on July 24, 2009


He3 mining... ON THE MOON!

By SPOILERS!
posted by Naberius at 12:53 PM on July 24, 2009


Let's take away your GPS, satellite phone, television, international communications, XM radio, Google Earth, and weather forecasting. Now ask the question again

But those things already exist with the current system (using government-designed and operated rockets). The technology required to get a payload into orbit already has massive amounts of money poured into it from governments all over the world because that's the method necessary to drop nuclear warheads anywhere on Earth at a moment's notice. XM radio is a good example, because they were able to put those satellites up there even though it turned out to be a relatively pointless and unprofitable idea. It seems like we've already hit most of the practical applications of having space vehicles around without needing to get to the point of having a space travel industry along the lines of the air travel industry, which these types of articles are always talking about.
posted by burnmp3s at 12:59 PM on July 24, 2009


Just to clarify it, by spaceflight I don't mean chucking a Volkswagen with a plutonium reactor into nearby orbit; I'm talking about people going to Mars and what most people mean when they talk about flying in space.

As to balancing the risk of humanity being wiped out, that's all well and good, but let's look at what that entails, namely a self-sustaining population of people with enough numbers and genetic diversity to go it long-term.

Meanwhile, we can't even manage Biosphere 2 right. They had to let more air in.

When we can get a station on Antarctica to be self-sufficient for fifty years, without having crates of stuff flown in, then I could begin to accept the "let's not put all our eggs in one basket" rationale, but until that comes to pass, it's just a handy justification for an exercise in ego, not an actual reason.

If we fail to prepare adequately, what we'll get is another "mission" where we spend an obscene amount of money to plant a flag and leave a footprint. Then we go home and feel god about ourselves for a few more decades. This does not accomplish the aforementioned goal.
posted by adipocere at 1:02 PM on July 24, 2009 [4 favorites]


The XM satellites were launched by a private company (Sea Launch). The rockets were designed by RKK Energia, based on a Soviet-era design, however.
posted by zsazsa at 1:07 PM on July 24, 2009 [1 favorite]


Just to clarify it, by spaceflight I don't mean chucking a Volkswagen with a plutonium reactor into nearby orbit;

Yeah, you say that now, but when I get my Type 2 into a a high orbit over Venus, who will be laughing then?

Ok, it'll probably be you, because I'll have just spent two months in a small bus with a plutonium reactor taking up the back end, but you get my point!
posted by quin at 1:55 PM on July 24, 2009


Mining a planet is unlikely to ever be a fruitful exercise (at least from Earth's perspective) for the reasons listed above. However, once you can cheaply and reliably get out of our own gravity well, there are plenty of precious minerals to be had without dealing with another planetary system. It's not too far-fetched to imagine an ion drive or something similar with low power requirements being placed on an asteroid to shift it closer to Earth orbit.

I do wonder what the governmental reaction would be to a private company playing around with world-killers though. You couldn't put it in Earth orbit due to the catastrophic consequences of a mistake, but it seems plausible to camp it out at one of the more distant Lagrange points. At that point, your existing orbital infrastructure starts really paying off, once you can launch with whatever payload or crew necessary and return full of precious metals.
posted by feloniousmonk at 2:07 PM on July 24, 2009


When we can get a station on Antarctica to be self-sufficient for fifty years, without having crates of stuff flown in, then I could begin to accept the "let's not put all our eggs in one basket" rationale, but until that comes to pass, it's just a handy justification for an exercise in ego, not an actual reason.

Can you not hear what you're saying? You're inventing a chicken and egg problem that would leave us still living in mud houses if people routinely following this thinking.

Progress doesn't work like that. The lunar module was developed concurrently with the spacesuit concurrently with the rocket concurrently with the command module concurrently with the navigation system, and so on. Any one of those could have stumbled and held back all the others, but if attempting to developing the technology all in sequence of proven, validated steps, today we'd still be decades from reaching the moon.

Progress - in all spheres - comes from being bold.

Spaceflight will be (and is being) developed concurrently with self-sustaining colonies. In both cases, success is decades away. It's a huge mistake to confuse that with failure just because it doesn't deliver now Now NOW!
posted by -harlequin- at 4:02 PM on July 24, 2009


No, that GPS and whatnot all stem from developments we made in accomplishing a goal

No, iodine water purification tablets and whatnot all stem from developments we made in accomplishing a goal. GPS stems from orbiting satellites, which we had to put into space because otherwise we'd have needed millions of them instead of dozens.

The other things backseatpilot listed, while not as grossly dependent on spaceflight as GPS, are still not "spinoffs", they are products and services that directly make use of orbiting satellites.

Still, even though 99.99% of the energy and material wealth in the solar system is off Earth, IMHO it's going to be a long time before we recover anything valuable from space other than data. And even when that happens it's still not very likely that scramjets are going to be involved. Not having to carry oxidizer on board hardly makes up for having to plough through it at hypersonic speeds. Spaceflight isn't expensive because it uses up too much liquid oxygen; that stuff's pennies per kilogram. Spaceflight is expensive because it uses up too many multi-million-dollar expendable spacecraft and too many thousands of highly trained specialists to run them. And based on (admittedly very limited) data so far, scramjets might actually make that last problem worse...
posted by roystgnr at 4:05 PM on July 24, 2009


Unfortunately, scramjet engine development (like the X-51A) is not meant for space exploration, but for weapons.
posted by Edward L at 4:32 PM on July 24, 2009


backseatpilot: "…rocket exhaust is supersonic due to the nature of rockets, so you can duct some extra air in with the exhaust to get some oxygen in to the scramjet inlet at supersonic speeds. Then you've got to deal with the extreme temperatures at the inlet as well as the outlet, but... like I said, this is off the cuff."

I don't think that would work — the rocket exhaust, unless the rocket was burning very inefficiently, wouldn't contain enough free oxygen to allow the scramjet's fuel to burn. You could tune the rocket so that there was oxidizer left in its exhaust, but then I think the "scramjet" would really just be a rocket, since it wouldn't be burning atmospheric oxygen.

What you might be able to do, and what is mentioned offhandedly in the article, is pulse a rocket engine. So rather than having a rocket firing continuously, you have it firing on and off, and in between pulses you "gulp" down some incoming atmospheric air, inject some fuel, and burn it. I don't know if that's exactly how the pulsed-rocket prototype is working, but that strikes me as a potentially plausible way to build a rocket/ramjet hybrid that would be somewhat more efficient than just a pure rocket engine. Even if the ramjet wasn't that good, in the sense of being able to propel the vehicle on its own, since most of a rocket system's weight is oxidizer, any system that generated additional thrust without wasting oxidizer might be a useful addition.
posted by Kadin2048 at 5:52 PM on July 24, 2009


Based on the first of the three pages, which is all I was able to force myself through, that was a poor quality article, and I hope it's not indicative of New Scientist in general.

Based on the comments here, though, it appears that nobody else read it either.

I watched the 2004 X-43 scramjet test live. So there.
posted by intermod at 6:18 PM on July 24, 2009


Is it possible to build a 14 mile long linear accelerator to get scramjets up to mach 4?
posted by BrotherCaine at 7:47 PM on July 24, 2009


From the article: [Reusable scramjets have] proven elusive so far: all scramjet test vehicles have been intentionally destroyed after their brief period of use, largely because they burn out. The obstacles to greater scramjet robustness are many. Top of the list is keeping air moving through the engine at sufficient speeds for combustion, as well as preventing the engine from melting.

Yes, that could be a problem.

Like many New Scientist articles, it has an attention grabbing headline and then turns out to be exaggerated, provisional and contentious.
posted by memebake at 5:15 AM on July 25, 2009




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