Hypersonic Test Aircraft Peeled Apart After 3 Minutes of Sustained Mach 20 Speed 191
coondoggie writes "DARPA's experimental Hypersonic Technology Vehicle (HTV-2), lost significant portions of its outer skin and became uncontrollable after three minutes of sustained Mach 20 speed last August. That was the conclusion of an independent engineering review board investigating the cause of what DARPA calls a 'flight anomaly' in the second test flight of the HTV-2. Quoting the report: 'The resulting gaps created strong, impulsive shock waves around the vehicle as it traveled nearly 13,000 miles per hour, causing the vehicle to roll abruptly. Based on knowledge gained from the first flight in 2010 and incorporated into the second flight, the vehicle's aerodynamic stability allowed it to right itself successfully after several shockwave-induced rolls. Eventually, however, the severity of the continued disturbances finally exceeded the vehicle's ability to recover.'"
Disposable Vehicles? (Score:2)
650 miles in 3 minutes? I'm SO there!
Re:Disposable Vehicles? (Score:5, Funny)
Fortunately, we'll have disposable people riding in it.
Re:Disposable Vehicles? (Score:5, Funny)
Fortunately, we'll have disposable people riding in it.
Finally, a use for Intellectual Property Lawyers!
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Depends on how fast you intend to do it. For the human body it's all about acceleration, the speed doesn't really matter.
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There was a time when people were asking if we could handle the forces needed to go 25 mph. I suppose there must eventually be a limit, but so far the answer has always been "under the right circumstances, yes."
Comment removed (Score:4, Interesting)
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Well.. yes, of course. It's all a matter of how long a period of time the acceleration takes place over, which I don't know.
Uhm, the deceleration, on the other hand.. is a fairly known value.. and in excess of what we can handle. You'd certainly get there, though! All OVER there!
Re:Disposable Vehicles? (Score:5, Informative)
It depends on how long it takes to get to those speeds. At 9.8m/s^2, easily handled as evident from people parachuting, it would take about 11 minutes to reach mach 20. Once you reach that speed, there's no problem going that fast just because of speed...spacecraft have been doing that for some time. Apollo 10 holds the record for fastest manned vehicle at nearly 25,000MPH.
According to the g-force wiki page [wikipedia.org], early experiments showed that untrained individuals could survive 17g's accelerating and 12g's decelerating (in a facing forward orientation) which would translate to 40 and 56 seconds respectively.
The maximum recorded g's sustained by a person for more then a split second is 46.2g's and it would take 14.5 seconds of acceleration or deceleration to match that rate.
The hard part about going that speed is the friction and stresses on the aircraft flying through the atmosphere.
Expert opinion (Score:5, Interesting)
As a person who flies hypersonic aircraft for a living this is notable on several layers.
1. They did a test and it went far past hypersonic (M5).
2. They achieved M20, altitude adjusted
3. All that happened after 3 minutes is the materials failed
4. It lasted 3 minutes!
To me this is a stupendous success.
I am a hyper-critic of most of the hypersonic tests we all hear about.
Spend more money on this.
JJ
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You fly hypersonic aircraft regularly? You either are: an space shuttle pilot, a military test pilot breaking his clearance, or making shit up. Who modded this up?
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You run Linux regularly? You either are: a central processing unit, a graphics processing unit operating outside of its designed architecture, or making shit up. Who thinks this stuff up?
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Spend more money on this.
Because it's good for...what exactly? I fail to see the practicality of a plane that goes so fast it burns itself to pieces.
Re:Expert opinion (Score:4, Insightful)
Because it can teach you how to build a plane that goes that fast and *doesn't* burn itself to pieces. This is the closest we've ever gotten to that.
Re:Expert opinion (Score:5, Insightful)
The fact that they corrected the problems found in the first test, and have a clear idea about why the second test failed, speaks very well to this program. I look forward to reading more about it.
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And what's the ultimate goal? To build an aircraft that goes faster than the previous ones? With enough money you can always best the previous record, but after a while it becomes pointless, just like those record speed cars that are basically just a rocket on wheels. This is basically just a rocket on wings.
Get to LEO with an air-breathing engine?
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The vehicle is question is a rocket powered glider, so in this case it is all about re-entry, so basically nothing but weapons technology.
Launch over your own territory, get to required altitude over international territory and then initiate attack run.
attack is done at high speed, target need not necessarily be fixed before hand, given range to target and time allowed to shift, vehicle is either the warhead or drops the warhead/s.
So US is back to weaponising space again. At these high speeds you don
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And what's the ultimate goal? To build an aircraft that goes faster than the previous ones? With enough money you can always best the previous record, but after a while it becomes pointless, just like those record speed cars that are basically just a rocket on wheels. This is basically just a rocket on wings.
Get to LEO with an air-breathing engine?
Get Pizza delivered under half an hour? - from Italy.
Re:Expert opinion (Score:4, Interesting)
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Re:Expert opinion (Score:4, Interesting)
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"I am a hyper-critic" all hot air, and noise?
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You fly hypersonic (mach 5+) aircraft for a living? Really?
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As a person who flies hypersonic aircraft for a living... JJ
I don't see your name here [wikipedia.org]. Who are you? What do you fly? Please tell me it's not a flightsim!
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I would not be surprised to learn that there were a few hypersonic aircraft pilots flying planes we don't know about from locations we don't get to see. Aurora for instance has been around for years in semi-rumor form, for instance. That would make it entirely possible there were hypersonic pilots not not the list you reference.
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Sure, but entirely impossible that those pilots would post about it on Slashdot. Unless JJ wants a quick exit from the hypersonic plane flying game and a head start on the classified federal prison one.
Re:Expert opinion predictable whining (Score:3, Informative)
I fly unmanned hypersonic aircraft. I would call these rockets spacecraft except they don't go to space.
I and nobody else flies "in" them. The temperatures are too high.
Even SS1 had a peak velocity of altitude adjusted 240 knots at sea level.
The goal here is a 1 hour to target RPV. Not a passenger aircraft and not Fedex to China. This is a military thing. Rediculous cost.
BTW you can see my M5 "aircraft" on the web anytime you want. Search for 152mm rocket in the USA. The 229mm one goes faster and the 45
Not so bad... (Score:4, Funny)
They only need to achieve 39 more minutes of flight time and they'll match the range of a 787!
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And get there in 42 minutes!
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Re:Not so bad... (Score:4, Insightful)
It already happens -- even today you sometimes spend more time in the airport at each end than you spent in the air.
I wonder if a hypersonic passenger craft would have to be cleared for landing before they even took off?
Great, a idea for a subplot in the next SAW movie (Score:2, Funny)
James Han and Leigh Whannell are probably working on the plot right now...
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Why do that when you can just sandblast them?
Time for MD-3 (Score:2)
Mass driver tech can accelerate buckets at 5000m/sec^2. Buckets using this hypersonic tech, a 6 km mass driver in a very high place, say Tibet, and we could chuck stuff into orbit at 1/100th the current cost.
Am I missing something, or should we start construction?
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Air drag goes up as a fourth power of the speed.
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I don't have a problem with China developing a launch capability, but if it bothers you, then pick some other location - Boliviaâ(TM)s Potosi, the Rocky Mountains, ... any place both high and not ridiculously remote.
Glass half empty, or half full? (Score:5, Insightful)
IMHO, this was not a failure, just another step forward. We learned something useful, to be explored/applied next.
Good job, folks! Keep moving forward....
DARPA = Advance Research Projects (Score:2)
Of course it fell aprt (Score:5, Funny)
If advanced planes work perfectly, we will never get a Bionic Man.
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If advanced planes work perfectly, we will never get a Bionic Man.
Don't worry, I'm old enough to find that funny.
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Yes, and soon enough six million dollars will be mere pocket change! Our cybernetic programs are getting cheaper by the decade!
Localized Electromagnetic Field Research (Score:2)
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Maybe if they put LEDs on it....
One word (Score:2)
Unobtainium
Link to the actual press release (Score:5, Informative)
Here's the actual press release (which Network World just cut-and-pasted): http://www.darpa.mil/NewsEvents/Releases/2012/04/20.aspx [darpa.mil]
Oh no (Score:2)
Atmospheric hypersonic flight waste of money (Score:2, Interesting)
The only practical way to obtain hypersonic speeds is to go suborbital, and that really enters the realm of rockets as heat shields are very heavy.
I think the developers of the SR-71 could have predicted these failures. The SR-71 _only_ went Mach 4 or so, at altitudes of greater than 60,000 feet or so. And at full speed the plane was so hot that pilots couldn't touch the canopy of the cockpit (I think the skin temps were at least a 1000 degrees pick your unit) and the plane lengthened by some cons
Re:scientifically (Score:5, Funny)
Right. Glad you grasped the point of the project so well, and didn't try to wedge in some off-topic nonsense.
slashdot (Score:5, Informative)
This is slashdot. The only point of comments now is off-topic nonsense, hopefully modded 'informative'
Re:scientifically (Score:5, Insightful)
Which "technology"? (Score:5, Funny)
When you say the fuel source doesn't matter, are you referrring to sustaining speeds of Mach 20, or to the plane's Rapid Unscheduled Disassembly feature?
Re:Which "technology"? (Score:5, Funny)
As far as I can tell, the "Rapid Unscheduled Disassembly feature" seems to be fully wind-powered.
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Spontaneous thermal self dis-assembly has been a euphemism for blowing up your motor for decades. It predates Apple.
Re:scientifically (Score:5, Insightful)
And scientifically, it went around 750 miles in 3 minutes. In an atmosphere. That's a pretty damn awesome piece of engineering.
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Scientifically that's awesome, but practically... couldn't you achieve the same kind of speed by popping into LEO?
I am wondering which would be more practical for one of the obvious end uses of this product, namely making the Concorde look more like a turtle.
Re:scientifically (Score:5, Interesting)
If you can go that fast in an atmosphere, you can use an air-breathing engine to get you most of the way to LEO...
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Even better, the same technology that lets you fly in atmosphere at such extreme speeds would likely aid reentry, wouldn't it?
Re:scientifically (Score:5, Informative)
In theory, yes. The type of design (a "waverider") places the hypersonic shockwave directly beneath the vehicle. Basically, you're surfing the shockwave. This reduces the stresses involved, improves stability and should allow considerably more control than could be achieved with the space shuttle (you have sufficient lift from a waverider to glide). Waveriders do have disadvantages - most designs only work at specific speeds, the wings have a habit of frying and they rely on cooling by radiation (only effective at high altitude).
Old wisdom on waveriders:
http://research.lifeboat.com/surf.htm [lifeboat.com]
http://www.aerospaceweb.org/design/waverider/waverider.shtml [aerospaceweb.org]
Published theory:
http://www.waset.org/journals/waset/v79/v79-79.pdf [waset.org]
http://www.dept.aoe.vt.edu/~mason/Mason_f/ConfigAeroHypersonics.pdf [vt.edu]
Multi-speed waveriders:
http://www.springerlink.com/content/x75nh2154nuh5464/ [springerlink.com]
Amateur waverider research:
http://www.gbnet.net/orgs/staar/waveriders.html [gbnet.net]
NB: The STAAR group beat NASA and the US DoD to the first working waverider airfoil, as noted on their site. Perhaps NASA's problem with their current design is that they're not threatening the engineers with bagpipe music.
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You can also replace ICBMs with this for a fraction of the costs. And it can be dropped from a plane or a ship anywhere we want.
Re:scientifically (Score:4, Interesting)
ICBM systems are sunk costs. Some possible salvage value as booster stages, but basically the money is gone. Better to keep them functioning lest someone try to collect on our debt.
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Research costs are always high. However, in principle, a basic waverider with a hydrogen-powered scramjet aught to be a lot cheaper than an ICBM (hydrogen being a much cheaper fuel, and 100% of the vehicle is reusable).
Note - that's in principle. Practice rarely pays much attention to theory. A space elevator would be nice, too, as would a pony.
The biggest problem is that the hypersonic craft was NASA's last shot at this for a while. The last time the test craft was covered, it was stated that the project i
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As the hypersonic craft demonstrated so well, there is a vast gulf between what theory says could be done and what can actually be done in practice. The only way to know is to build.
Secondly, and more importantly for NASA, something like a BWB airliner could perform high altitude research currently impossible because no conventional aircraft has the lift capacity or the space availability. NASA use aircraft extensively in research, but are usually stuck with aircraft wholly unsuited to what they want to do.
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Re:scientifically (Score:5, Funny)
640mi (in 3 min) should be enough for anyone.
So just slow it to Mach 19.7.
Re:scientifically (Score:5, Funny)
And scientifically, it went around 750 miles in 3 minutes. In an atmosphere. That's a pretty damn awesome piece of engineering.
Meteors do that every day. And, they have the same end result.
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Are you saying that meteors start at a much lower velocity, then accelerates to those speeds before falling apart? And that they're engineered?
Re:scientifically (Score:4, Informative)
You realize it was boosted to speed on a conventional rocket? Don't mistake an aerodynamic testbed for a working vehicle.
Re:scientifically (Score:4, Interesting)
What's even cooler, that speed is close to orbital speed. So with little additional thrust this plane can make it into orbit!
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That's part of the point. A working scramjet, if it can have sufficient payload, may be a much more effecient way into orbit.
Re:scientifically..or not (Score:5, Informative)
Except for the fact it runs on hydrogen peroxide and methanol. Plus, I'm given to understand the proposed full scale version would run on hydrogen slush and LOX.... aka rocket fuel.
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Point taken. There are other fuels. Frozen methane, ammonia come to mind. There are rocket scientists, chemists, and propulsion engineers who make their living on this stuff.
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Do you really want it to be nuclear-powered?
Fuckin' a, bubba.
But just skip the atmosphere. If you really want to go that fast, go straight to orbit (and back, if so desired).
Re:WHAT THE FUCK IS THE ALTERNATIVE? (Score:4, Informative)
So what the fuck is the alternative, then?
Um, it's a glider [darpa.mil], launched from a rocket, which would probably use a hydrogen based rocket fuel or some other.. um.. why am I answering an AC?
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Fortunately, hydrogen is easily producable from the most common substance on earth - water. Just add energy, which can come from any number of sources. /most/ fuels in terms of availability.
Sure, it may not be 100% effecient to get it that way, but it is an option. And is easier than making
Re:WHAT THE FUCK IS THE ALTERNATIVE? (Score:5, Funny)
What I really want is a bicycle powered, mach 20 vehicle. And a unicorn. And some waffles.
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unsymmetrical dimethyl hydrazine & aniline careful they're hypergolic!
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...so take off all your... skin?
I think you mean "so have all your skin rubbed off".
Yowch.
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Isn't that close to reentry speed? What did they expect? If we had a cheap, durable, stable material that could stand up to that for any length of time we would have used it on the Space Shuttles and maybe kept them flying for another 10 years.
That's the point of DARPA. To figure out how to answer these sorts of questions.
Re:Close to re-entry speed (Score:4, Interesting)
And while they're busy doing that they often manage to put on one hell of a show:
* this effort
* the autonomous vehicle DARPA Challenge
* other random bits that we read about
* certainly other random bits we have no idea about, but I bet they're cool!
-nB
Re:Close to re-entry speed (Score:4, Informative)
And while they're busy doing that they often manage to put on one hell of a show:
* this effort
* the autonomous vehicle DARPA Challenge
* other random bits that we read about
* certainly other random bits we have no idea about, but I bet they're cool!
-nB
also..
* the fucking Internet
you kids these days need to learn your history
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The Advanced Research Projects Agency Network (ARPANET), was the world's first operational packet switching network and the core network of a set that came to compose the global Internet. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks. ARPANET became the technical core of what would become the Internet, and a primary tool in developing the technologies used.
First ARPANET IMP log: the firs
Re:Close to re-entry speed (Score:5, Insightful)
Flying real hardware is still the only way to conclusively
1. Learn Something (if it has problems) or
2. Silence the critics (if it works fine).
IMHO, while a good number of aerospace contracts can be criticized for either being pork or thinly veiled airliner-maker subsidies, that should be focused on those never producing an instrumented flight.
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Regina Dugan recently did a TED talk in which she says The only way to learn to fly is to fly [ted.com]. Great stuff.
And while it sounds stupidly reasonable, it really is true that you cannot learn how to fly without flying, just like you cannot learn how to walk without walking, swim without swimming or speak without speaking.
Yet it always amazes me just how many people fails to understand such simple premises when it comes to science. They seem to think that failures aren't science and that nothing is learned from
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Yet it always amazes me just how many people fails to understand such simple premises when it comes to science. They seem to think that failures aren't science and that nothing is learned from them.
But if you then ask them about gravity, they'll almost always talk about Newton, yet if you point out that Newton got it wrong (mostly right, but still wrong), they will invariably tell you "that's different".
That's unhelpful. Newton's work on gravitation was based on a lot of previous work by other scientists over a long time; experimental work, observational work and theoretical work. Newton was the guy who first pulled it all together into a coherent framework, but he couldn't have done it without Copernicus, Brahe, Kepler, Galileo, probably many others. What replaced Newtonian dynamics? Relativity (which reduces to a damn good approximation to Newtonian for most everyday activity) and that was Einstein build
Re:Close to re-entry speed (Score:5, Insightful)
Yes. Science and engineering are often advanced by never doing anything you are not absolutely certain will work perfectly.
Re:Close to re-entry speed (Score:4, Insightful)
Many, many
It seems we have completely forgotten the words 'trial and error', and 'that's interesting...'
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Not only we.
The recent rise in article retractions (calling it "fraud" is too general, but that's one of the reasons) is also caused by this change in attitude.
See, we don't expect interesting stuff from science anymore. We expect marketable results. Getting something else than you set out to find means that marketing, product management and everyone else down the line has to re-tool and, more importantly, re-think and we can't have that. We already printed the packaging and filmed the TV spots!
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As to not trying this, you have to be a fucking idiot to think that we should not try this. It is from this test ride that they figured out what issues they had.
And if you think that scientists and engineers should not test things, I bel
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But the space station is much farther out, I think the linear velocity of the space station is higher as well, however, good luck doing that in anything but the thinnest wisps of atmosphere in LEO.
-nB
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I guess dipping it in liquid plastic, or just wrapping a really big roll of clingfilm around it wouldn't really cut it?
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Graphene clingfilm perhaps? :-)
Re:the point, exactly? (Score:5, Insightful)
But Mach 20? Really? Does it really serve a purpose other than finding out that we can push the limits of things?
Purpose? Probably to build a long-range bomber that can hit a target anywhere on Earth a few minutes after it's been identified. Or to build a vehicle that can reach low Earth orbit and return. Or maybe just to see what's humanly possible.
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I know I'm probably coming off as ignorant but I'm not necessarily saying this project doesn't have a noble purpose. I'm just asking what it is exactly...
Sub launched or fighter delivered short range nuclear weapons. First strike, or retaliatory strike, it doesn't matter.
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no, it's specifically aimed at conventional weapons, not nuclear. the point is NOT to send an ICBM, because doing so tends to make our Russian or Chinese friends get all retaliatory (even if it's not nuclear tipped.. how do they know?) - instead this thing would fly through the atmosphere and deliver a conventional payload.
it's intended to be a very, very fast cruise missile, with the objective of being able to hit any point on the planet in an hour or less.
Re:the point, exactly? (Score:4, Insightful)
several points (not all covered here, these are just a few that immediately popped into my head):
-from the telemetry they can determine how exactly the materials and structure failed. From this better material and structure design for slower aircraft making them more survivable;
-from the telemetry they can determine the high stress points on a craft travelling at such a speed (I can imagine, the leading edges of the control surfaces, the wingtips and the nose will get stupendously hot and massive vortices spilling from the trailing edges may have had something to do with the failure of the superstructure). Again, this leads to improvements in aircraft design;
-from observation and telemetry they can determine the aerodynamic stresses at the moment of failure.
As lessons previously learned: in reinforced carbon composite skinning, it is known that several thin and continuous layers are far stronger than a single thick, segmented layer. This principle is used in hulls on sporting boats, as hull integrity at speed is kinda important. When we learn how to spin alloys into a contiguous undulating skin we'll be doing well.
Consider also that without such pioneers as Chuck Yeager we would not have transsonic or supersonic airliners. We would not know how to compensate for TS turbulence, or how differently control surfaces behave across the sound barrier, or how baffles slow intake air enough so as not to shatter fan blades, or most importantly, how the human body reacts to such unnatural velocities.
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Consider also that without such pioneers as Chuck Yeager we would not have transsonic or supersonic airliners.
Umm... we don't. That 1970s french/brit thingy crashed, and that was that. It just costs to damn much to fly an airliner past Mach-1. It's like commuting 30 miles to work every day in a Bugatti Veyron at 2 mpg.
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The point is, we did. We not only had the Anglo-French Concorde, the Russians also developed the Tupolev TU-144, AKA "Concordski". OK, Concordski only completed just over a hundred commercial flights but it was still in use by NASA (among others) as test platforms, until 1999. Boeing started (but did not complete) two prototypes for its 2707 SST project. A-F Concorde had only three times the fuel running costs per passenger than the Boeing 747-400, which isn't a big deal when you consider that there were pe
The point is: attack and destroy (Score:2)
Any target, anywhere on earth, within less than an hour, without condemning the attack missle to a predictable and easily observable flight path in orbit. (Compare that to the pathetic "threat" of a North Korean satellite launch.)
Science it ain't.