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Blackswift Spaceplane  (Source: Image Via Danger Room)
DARPA revives Reagan era hypersonic aircraft dreams with Blackswift

Back in the 1980's during the Reagan administration plans were announced for a new Orient Express, which amounted to a plane that would take off and land like a normal aircraft, but cruise at Mach 25 making runs into low Earth orbit as it went from Dulles airport to Tokyo in two hours.

Obviously, since the flight still takes most of a day to make, the plan for the new Orient Express didn’t pan out as hoped. DARPA is coming back around to the idea of a hypersonic vehicle, but not to the extreme the Regan era government tried to undertake.

The new hypersonic project, dubbed Blackswift, shares the same take off and land normally approach. It aims for a more achievable speed of a Mach 6. Blackswift came from a DARPA project called Falcon that originally intended to build a family of hypersonic test vehicles.

Details of the project point to the famed Lockheed Skunk Works as the main contractor for the vehicle. Reports are saying information gleaned from several sources point to Blackswift being a fighter sized unmanned aircraft.

The propulsion system to take Blackswift to the Mach 6 speeds is a hybrid power plant consisting of a combination turbine engine and ramjet. The turbine engine would take the aircraft up to Mach 3 where the ramjet would kick in and carry the craft up to the Mach 6 cruise speed. Blackswift reportedly doesn’t have the backing of the Air Force at this time, which will obviously be crucial to the project reaching maturity.

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By PaxtonFettel on 8/14/2007 4:36:25 AM , Rating: 5
You got me all excited! The headline makes it sound as if they've already achieved it, should be more like 'Blackswift Hypersonic Aircraft To cruise at Mach 6' to stop fellows like me getting their knickers in a twist.

And a real question: How the hell does this thing turn? I'm guessing it has to leave cruise for even the slightest manoevre as the angular momentum from even a small turn at M6 would be immense. Is it even meant to?

RE: Misleading!
By MGSsancho on 8/14/2007 5:19:39 AM , Rating: 3
it can turn, just its turning radius will be huge, the SR71 had a turning radius of 72 miles. im to lazy to do the math, but i would not be surprised it it could not turn with in the state of California.

RE: Misleading!
By alifbaa on 8/14/2007 9:15:24 AM , Rating: 5
The rule of thumb I use to calculate turn radii when I'm flying is "Miles per minute minus 2." In my much more normal case of cruising at bout 500 knots, that's something like (500/60)-2=6.33 miles. Using that formula, an aircraft traveling at Mach 6 would be (3970/60)-2=64 miles.

The 72 mile figure you quoted for the SR-71 (3.3 mach region) is likely a turning diameter, not a radius. Applying the formula, we get (2180/60)-2=34 miles. Multiply that by two, and you get a 68 mile turn diameter, which is very close to the 72 mile figure. At mach 6, we'd be talking about a 128 mile wide area needed to turn around!

As for the earlier comment about angular momentum tearing the plane apart in a turn, that wouldn't be a problem. To put it simplistically, G loading is what both turns an aircraft and can tear it apart. An aircraft moving at this speed and trying to turn as tight as a fighter would generate enormous G-loads, and would likely either break apart or be built too heavy to fly efficiently. The only solution is to decrease your max G-load, thus increasing your minimum turning radius. As you said, any aircraft can turn, it's just a question of how much room it needs to do so. At mach 6, a person sitting in an airplane turning at the same rate as an airliner traveling at .8ish would notice absolutely no difference between the two.

RE: Misleading!
By MGSsancho on 8/14/2007 10:26:38 PM , Rating: 2
check out this book,
page 128, turn radius in a level turn is R = V^2/(g*sqrt(n^2-1)), where V = flight velocity, G acceleration due to gravity, and n is load factor. so your rule of thumb does not quite work. but works as a good estimation. The number i got was probably correct, and you are probably right. I remember reading here that due to the force of acceleration, you can not pull more than 3Gs in a turn or the engine breaks off.

RE: Misleading!
By alifbaa on 8/14/2007 10:56:25 PM , Rating: 2
Yeah, I looked that one up after I posted and found the real formula again. I don't know about you, but I'm barely capable of doing that with a calculator on the ground, much less doing square roots in my head while simultaneously navigating, flying an aircraft, and talking on the radio! I settle for the in-precision of an easy calculation and call it good enough. I leave the real formula for the engineers.

Regarding the 3G limit, that's a pretty cool link. The 3G limit is a design factor the engineers decided upon. Like I think I said earlier, the trade off is essentially between weight and performance. In a fighter, (typically stressed to 12+ g's) you can design for performance, and put a big ass engine on it to develop enough speed to overcome the bulk of the strong structure required to sustain high G's. In an airliner, maneuverability isn't as important, but efficiency and payload are. The result is that most airliners are only stressed to 2.0 or 2.5G.

The SR-71 was probably designed with either a little maneuverability or less safety in mind, and thus had a higher G loading. With the engines being mounted outboard, it wouldn't surprise me at all if they were the limiting factor. That's a lot of weight and therefore a huge moment arm out there just waiting to break free.

As a frame of reference, a normal airliner turn will be at a maximum of 30 degrees of bank, generating 1.1G's in a level turn. At 45 degrees, the plane will be loaded to 1.3G's. At 60 it's 2.0. At 75 it's 4 or 4.5 (I can't remember. It's been a while since I've been past 60,) :-(

It's also common for designers to attach engines in a way that ensures they melt their mounts before burning into the wing in the event of an uncontrolled fire. This often leads to weaker engine mounting structures than would otherwise be present. I have no idea if the SR-71 was designed that way, but I know all medium and large aircraft that I've ever been involved with have had that feature.

RE: Misleading!
By MGSsancho on 8/15/2007 2:53:06 AM , Rating: 2
you are correct on everything, when i posted to your reply, my buddy is an aerospace engineer and he was standing over my shoulder at the time. yeah the SR-71 wasn't very maneuverable at all. but at those speeds I do not think it would be.

anyways, in the reading of the engines, if the front end of the J58 engines were designed today, they could overcome some design difficulties. i heard that with modern tools, the engine could do mach 6. although I find it hard to believe,
Those bad boys get extremely hot. from my aerospace engineer buddy, its more of a materials problem. oh well I can not wait to hear more on this no fantastic plane. some pics of it taking off and turning would be awesome. I don't know care about sensors. the plane itself is amazing. Also and lastly, if a commercial version could be made. Los Angeles to Tokyo in a few hours would be great. and yeah yeah I know at higher altitudes speed of sound is slower and yadda yadda... i just want to fly one.... and do an aileron turn

RE: Misleading!
By dougdaniel on 8/15/2007 11:26:34 AM , Rating: 2
I need a little help understanding your comment about the outboard mounting of the engines. You said,"...That's a lot of weight and therefore a huge moment arm out there just waiting to break free. ..."

It seems to me that outboard engines would be closer to the spanwise center of lift of the wing than engines in the fuselage. I would think that that would reduce the moment rather and increase it.

Where did I go wrong?

RE: Misleading!
By timmiser on 8/14/2007 5:59:41 AM , Rating: 3
I would think that at that speed, it would be kind of important to be pointed in the right direction before you light the fires so that you don't have to turn more than minor corrections. (Kind of like space travel)

If you want to turn around, I believe the theory would be similar to your car on the highway; slow down to nearly a stop and pull a U turn.

RE: Misleading!
By Misty Dingos on 8/14/2007 9:06:18 AM , Rating: 2
The AF is not going to back this thing. They already have a replacement for the Blackbird. Look up 'string of pearls contrails' and 'uncorrelated seismic events in California' then you will have some idea of why the Blackbird was retired. Since the AF already has a high-speed ultra-high altitude surveillance aircraft why would the dilute their money on this quasi commercial venture?

No I am not wearing a tin-foil hat. And aluminum hats don't work.

RE: Misleading!
By ToeCutter on 8/14/2007 10:16:01 AM , Rating: 4
No I am not wearing a tin-foil hat.

You sure about that?

Google's first return on your suggested search string is a website called ;-)

RE: Misleading!
By Misty Dingos on 8/14/2007 10:44:12 AM , Rating: 2
Nope just checked. Unless I am being controlled by THE CONSPRIACY to mislead you all!


pitter patter of little feet as I run screaming from the room....

RE: Misleading!
By geddarkstorm on 8/14/2007 1:24:27 PM , Rating: 2
You don't need conspiracies to know the Air Force already has something. They would never have retired the blackbird unless they had a successor, obviously--and look at how long the blackbird was a secret from the public. I believe the successor is the Aurora, if I remember correctly. This thing will definitely not be used as a spy plane since it has been publicly announced, which totally defeats the purpose of being an unknown, secret craft necessary for spying.

RE: Misleading!
By GoatMonkey on 8/14/2007 3:00:27 PM , Rating: 2
I'm sure they could come up with a use for this plane. Never underestimate the government's willingness to spend your money.

RE: Misleading!
By timmiser on 8/14/2007 5:30:45 PM , Rating: 1
It's no secret why the SR71 was retired. The network of spy satillites are always up there, have much higher resolution, don't put a pilot in harm's way, and don't have the cost associated with maintaining an aging and expensive bird.

RE: Misleading!
By Cygni on 8/14/2007 7:15:04 PM , Rating: 2
Bingo. Whats the point of incredibly expensive aircraft when youve got satalites watching 24/7 anyway?

Im sure the Air Force has various high speed, high altitude projects. They would be foolish not to. But i can guarantee that none of them involve spying or bombing. Infact, i find it far more likely that they are involved in ICBM interdiction.

RE: Misleading!
By Fritzr on 8/15/2007 9:23:14 PM , Rating: 2
The satellites are also in mapped carefully watched orbits. USAF has an unannounced spy plane of some kind.

Don't need a tinfoil hat for that one :D

RE: Misleading!
By Anonymous Freak on 8/16/2007 12:59:55 AM , Rating: 2
"Aurora" is not a currently flying craft, and was never what the popular media described it as.

Blackswift is something in active development.

Yes, I have friends that work, or are retired from, the Lockheed Skunk Works, and the Intelligence departments of the Air Force, and while they can't give me 'real' details, they have confirmed beyond "cannot confirm or deny" that "Aurora", as it was popularized by Popular Science and Popular Mechanics, did not exist.

The Air Force has been without high speed, high altitude reconnaissance aircraft since the retirement of the SR-71.

The Skunks Works contacts have similarly confirmed that there is (or was as of a couple years ago,) an Air Force project under way for airborne high speed, non-satellite, reconnaissance. Based on the details I have gleaned, this new project sounds like exactly what has been described to me. (I was never told the codename Blackswift, however.)

These are two sources that are 100% independent of each other. While it is possible that the two knew each other (one was just starting at the Skunks Works right before the other retired,) I am about 99% certain that neither realizes that the other knows me. (The retired one moved away from SoCal after retiring, and I met him/her after the move; the other I know from college.) (And the positive "there is an SR-71 replacement under development" quote was given while under extreme drunkenness, but this person has never lied while drunk before.)

RE: Misleading!
By murphyslabrat on 8/20/2007 7:25:07 PM , Rating: 2
No I am not wearing a tin-foil hat. And aluminum hats don't work.

Good thing too, as the aluminum foil actually works as an antena within the government-reserved radio frequencies.

RE: Misleading!
By rushfan2006 on 8/20/2007 12:31:01 PM , Rating: 2
AS luck would have it, I actually had issues sleeping last night so at like 1 or 2 AM I was watching the Military Channel and the special show was all about jet technology. In the show they talked about the progressive technologies --- conventional jet engines (good for just about Mach 3), then the next step up is Ram Jet technology (good for about mach 3 - mach 5, maybe a little more)....and the latest and greatest is Scram Jet technology which the show's narrator simply left at "Mach 5 and beyond".

Anyway the show claimed the was an aircraft just last yet they tested trying to hit mach 5 -- but it actually hit mach unless the Military Channel is full of it -- actually they DID go past Mach 6 already and this article has their information wrong.

I wish I rememberd the name of the aircraft or the show - but at the time I didn't think it would be relevant for retention and I was kind of miserable for not being a sleep.

The show did say scramjet is the way to go and the wave of the future.

And for the other poster or posters who say "why do we need this technology when we have satellites"....well because its how they advance jet technology for more than just military that's why.

The goal (again from this same show) is one day realizing a commercial passenger air craft that can take you from NY to China in just under 2 hours.

By Gul Westfale on 8/14/2007 2:23:51 AM , Rating: 2
a worthy successor to the concorde? let's hope it sees the light of day...

RE: concorde
By CrystalBay on 8/14/2007 2:30:10 AM , Rating: 2
It's not very big is it ,past predictions have stumbled a little it seems...

RE: concorde
By cb62fcni on 8/14/2007 9:06:03 AM , Rating: 4
I KNOW! Look at the people in the background. What is this, a plane for ANTS!?!?!

RE: concorde
By drank12quartsstrohsbeer on 8/14/07, Rating: -1
RE: concorde
By lumbergeek on 8/14/2007 12:19:31 PM , Rating: 2
It's a UAV - nobody will be onboard. On the other hand, if you make one that can drop a tactical nuke, well even Osama can't run faster than Mach 6......

RE: concorde
By lumbergeek on 8/14/2007 12:21:25 PM , Rating: 2
Oh yeah, reference to my UAV comment - read the article fully and you'll come across the sentence: "Reports are saying information gleaned from several sources point to Blackswift being a fighter sized unmanned aircraft."

Unmanned Aerial Vehicle - UAV.

RE: concorde
By GoatMonkey on 8/14/2007 3:02:34 PM , Rating: 2

RE: concorde
By drank12quartsstrohsbeer on 8/14/2007 3:52:34 PM , Rating: 2
That may be, but the one in the picture is a wind tunnel model.

RE: concorde
By 3kliksphilip on 8/14/2007 7:19:45 AM , Rating: 3
mach 6 = 2 041.74 m / s

= roughly 2 Km / s

= 1.27 miles per second
= 4567 miles per hour

It's time you updated your brand, Gillette.

RE: concorde
By MGSsancho on 8/15/2007 2:03:22 PM , Rating: 2
mach 1 is the speed of sound. and the speed of sound is very dependent on temperature. As you increase in altitude, temp drops and the density of air decreases. So from simply using mach 6 to figure out the ground speed is impossible. unless you happen to know the outside temp of the air and altitude. However, 4,500mph is not a bad estimate

Speed of Light?
By GhandiInstinct on 8/14/2007 10:25:20 AM , Rating: 2
What Mach is the speed of light?

18,000 MPH right?

RE: Speed of Light?
By vortmax on 8/14/2007 10:41:06 AM , Rating: 2
You're a little off:

The speed of light would be about Mach 880,726 or so.

That's about 670,415,504 mph.

RE: Speed of Light?
By GhandiInstinct on 8/14/2007 11:58:28 AM , Rating: 2
So we've got a long way to go..maybe fusion engines will get us near that 600k mph mark.

RE: Speed of Light?
By lemonadesoda on 8/14/2007 8:23:39 PM , Rating: 2
It would take you a LONG TIME to reach that speed. Remember than the human body has a limited acceleration/deceleration capacity. It would take YEARS to reach those speeds. (And years to slow down)

RE: Speed of Light?
By JonnyDough on 8/15/07, Rating: 0
RE: Speed of Light?
By Doormat on 8/14/2007 10:59:29 AM , Rating: 3
182,000 miles per second isn't just a good idea, ITS THE LAW.

I saw that on a bumper sticker once. I laughed and no one else in the car got it.

RE: Speed of Light?
By lumbergeek on 8/14/2007 12:16:16 PM , Rating: 2
I remember that sticker - laughed my ass off the first time I saw it.

RE: Speed of Light?
By johnsonx on 8/14/2007 1:00:18 PM , Rating: 2
They probably didn't laugh because it's 18 6 ,000 miles per second!

Actually, 186,282 miles per second, but who can count mile markers at that speed anyway...

RE: Speed of Light?
By InsaneScientist on 8/14/2007 3:26:28 PM , Rating: 2
186,282.3971 to be even more precise. :D
Can anyone go further in the imperial system?

Or we could cheat and use metric, since c is exactly 299,762,458 meters per second.
A meter is defined as the distance light travels in a vacuum in 1/299,762,458th of a second (Why couldn't they have made it an even 300,000,000 >_<).

RE: Speed of Light?
By rcc on 8/14/2007 6:39:23 PM , Rating: 1
How about if we stick with the original definition, then we don't need silly numbers.

1 meter = 1/10000000 the distance from the pole to the equator. On earth of course. I'm sure they started jockeying with the definition because they realized that might not be an immutable standard. : )

However, that should answer the question as to why it wasn't an even type number. They were adapting the definition to the measure, not the other way round.

RE: Speed of Light?
By InsaneScientist on 8/15/2007 2:31:50 AM , Rating: 2
Yeah, I know they were adapting the measure to the definition... I was just complaining because it's a pain.

I have to admit, I didn't know what the original definition was... Why couldn't they have stuck with that?

I swear, sometimes I think that scientists like changing things just to drive normal people crazy (I.E. Pluto).

old tech
By MGSsancho on 8/14/2007 4:02:46 AM , Rating: 2
the SR-71 had hybrid engines.
Fantastic engines. I was hoping to read more on the powerplant system of this new plane. for more reading on ramjets and scramjets,

RE: old tech
By CBRf4i on 8/14/2007 1:56:20 PM , Rating: 2
yeah scramjets and ramjets are old, They should go with a PULSE DETONATION engine like what the aurora uses.

RE: old tech
By BladeVenom on 8/14/2007 2:33:31 PM , Rating: 2
Pulse detonation engines are even older. That's what the V-1 rockets in WW2 used.

RE: old tech
By InsaneScientist on 8/14/2007 3:33:43 PM , Rating: 2
V-1s actually used pulsejet engines. Similar concept to a Pulse Detonation Engine, but a whole lot less complicated to make and considerably less powerful.

To answer the question as to why they don't use a PDE on this thing, the answer is simple: no (unclassified) non proof of concept PDE has ever been built.

And they sure as heck aren't going to declassify the Aurora's engine just so we can get supersonic (or even hypersonic) commercial travel.

RE: old tech
By CBRf4i on 8/14/2007 3:47:16 PM , Rating: 2
Yeah that's how they get their concentric rings trailing behind, I meant "to go with the newer pulse jet engines" Like the combustible automobile engine hasn't fundamentally changed much since it's invention, but todays car engines are way more powerful, refined and effecient. So yes the pulse detonation jet is older technology, but using todays' spaced aged alloys, composites, polemers; etc... the pulse jet would be a more effienct engine i believe imo, since there is no afterburn to achieve sonic flight and sustain it.

RE: old tech
By InsaneScientist on 8/15/2007 2:54:46 AM , Rating: 2
Pulse Jet Engines are not the same thing as Pulse Detonation Engines.

They're a similar concept, but there are key aspects that are very different, leading to very different results. (Faster, more stable, etc...)

I don't feel like going into detail here, but the Wikipedia entry on the Pulse Detonation Engine has a decent comparison, though a few of the minor details are ignored.
Although, in all fairness, since there are no practial PDEs in production (that aren't black projects that we don't know about, anyway), as they're still in development, it's somewhat difficult to get exact info on the technology.

There's also a Popular Science article from a while back called "After Combustion - Detonation" (I think) that gives some good info. Unfortunately I can't find the issue, so I don't know which one it was.

The point is that, while Pulse Jets have been in use for quite some time, PDEs have not. They are new technology.

RE: old tech
By CBRf4i on 8/15/2007 10:43:29 AM , Rating: 2
I thought so.

RE: old tech
By DublinGunner on 8/16/2007 10:45:15 AM , Rating: 2
Would someone mind explaining what need there is for high altitude reconaissance craft in this day and age?

Satellite imagery has made the role redundant.

RE: old tech
By jjmcubed on 8/17/2007 11:59:11 PM , Rating: 2
Satellites go over at a certain time everyday. The people who don't want to be seen will be hidden at those times. Or so they say.... my foil hat isn't fitting as well as i would like.... /gets ducttape

never happen
By Treckin on 8/14/2007 9:13:37 AM , Rating: 2
This will never see commercial application. The way oil prices go, there is just no way that it will ever be viable to carry people at M6... even at 1000 dollars a ticket, and at 100 passengers, thats only $100,000. The fuel requirements are far to high at that rate of speed. I wouldn;t be surprised if we saw some of this technology in the next space shuttle revision. It's quite similar to the x plane concept.

There is also that little law against supersonic travel over populated areas, such as the United states... So supersonic travel to Japan seems unlikely, especially given that the wind currents over the arctic forbid such travel, the plane would have to traverse the continental US

RE: never happen
By alifbaa on 8/14/2007 9:23:52 AM , Rating: 2
Assuming some sort of hypothetical commercial, passenger carrying version of this were ever to take flight, it would likely fly supersonic at extremely high altitudes. If it flies high enough, like in the mid to upper 40k ft range, it could probably get the rules changed. If it flies above 50k ft, the current rules don't apply since it would be operating in uncontrolled airspace.

Having said that, the life support requirements when you fly above 50k are enormous. A sudden depressurization at those altitudes will cause unconsciousness in less than a second and boiling blood very soon thereafter. This will only increase the already enormous fuel costs such a craft would endure. I can't foresee a commercially viable version of this aircraft any time in the next 20-30 years.

RE: never happen
By omnicronx on 8/14/2007 9:55:12 AM , Rating: 2
Remember even the concord was only able to take travel to certain cities, usually right on the coastline. The sonic boom created when the plane hits the speed of sound is much too loud to be flying over land. So i wonder if this plane is capable of flying at very low speeds, especially at take off so that maybe it can be used as a commercial aircraft?

RE: never happen
By alifbaa on 8/14/2007 10:24:41 AM , Rating: 2
Right, and it went supersonic in the low to mid 40's, making its noise a lot louder at ground level. It also wasn't an American plane, and it came as jet travel had gotten really widespread only relatively recently. At the time, jets were literally 97% louder than they are today. Needless to say, people were much more sensitive to aircraft noise than they are today, and "window shattering" sonic booms was a politically expedient thing to ban. In reality, even the Concorde probably could have flown across the US without disturbing people. The ban was a response to largely unfounded fears. Planes regularly go supersonic over Nevada, and I have several friends that have inadvertently gone supersonic over far more populated areas without causing damage or disturbance. I even saw a boom get thrown during a blue angels show a few years ago. The plane was at about 500' and a quarter mile away. It didn't break anything and was nothing so loud that being separated by 40k feet of air wouldn't solve.

RE: never happen
By omnicronx on 8/14/2007 11:11:03 AM , Rating: 2
I have heard the sonic boom of a CF-18 (f-18) before too and its not that loud. But would a larger plane not make a louder noise? I am obviously not knowledgeable on the subject, i just wanted to know, as that was the reasoning for waiting until they were over the Atlantic before the concord could go supersonic.

RE: never happen
By stromgald on 8/14/2007 11:47:24 AM , Rating: 2
It depends more on nose shape than on size. However, generally speaking for most nose shapes, if you increase the size, the force of the sonic boom should go up.

RE: never happen
By jjmcubed on 8/18/2007 12:03:39 AM , Rating: 2
Saw an SR-71 at a show before it was retired and heard three sonic booms. The announcer says "Listen up in just a moment you will here three booms from the plane." You could BARLEY see the contrails in the sky... The booms were lower than I expected and I was quite disappointed. Think that was about 1986 at Beale AFB.

RE: never happen
By dougdaniel on 8/14/2007 1:22:31 PM , Rating: 2
There are some simple, back of the envelop calculations that would show (if I weren't too lazy to do them) that if the airplane stalled in cruise configuration at 200Kt CAS (calibrated air speed), that it would have to go supersonic about where the Concorde had to. Since the ram pressure on the leading edges of the airframe would be about 25 times ambient air pressure at M5.0, this bird will have to cruise much higher than Concorde to reach M6.0.

As far a U.S. laws about sonic boom; 1.) remember that they were passed after the SST project was cancelled, so the U.S. could reverse its position just as easily if we had a viable airplane; 2.) NASA has had some meaningful successes a reducing boom with an extendable probe in the nose of the aircraft which could mitigate the objections.

Wouldnt it be ironic if
By Shadowmaster625 on 8/14/2007 10:43:38 AM , Rating: 1
if one of these things flew by a deteriorating bridge, causing it to collapse? If the money that should have gone to fix the bridge instead went to pay for this thing...

RE: Wouldnt it be ironic if
By skyyspam on 8/14/2007 11:28:29 AM , Rating: 4
Put the bong down, dude.

By CBRf4i on 8/14/2007 2:23:25 PM , Rating: 2
If a jet can travel at the speed of light and turns on its headlights, do the lights ever come on?

RE: BUT!!?
By timmiser on 8/14/2007 5:39:32 PM , Rating: 2
Depends who you ask!

Great stuff!!
By DeepBlue1975 on 8/14/2007 8:20:21 AM , Rating: 2
Hope this project reaches maturity.
We've been crawling at subsonic speeds for decades, save for the short lived Concorde.
I wonder what altitude should this aircraft cruise at because, if mach 3 is a tough surface overheating test, at mach 6 I guess it should also be getting in some lower orbital plane (which would also help to keep fuel consumption lower).

Transforming powerplants
By dougdaniel on 8/14/2007 12:24:55 PM , Rating: 2
Let me predict that the power plant will be a hybrid low by-pass turbofan or pure turbojet whose intakes and exhausets can be closed off to form the plug of the inlet for a ramjet. I don't think that this configuration could get to mach 6 because at those speeds much (if not all) of the combustion must be supersonic. I believe the power plant must transform once again, this time into a scramjet.

just a single letter I know
By rdeegvainl on 8/20/2007 8:04:50 AM , Rating: 2
Sorry, but I am not familiar with the Regan era mentioned.. ;)
Though Regan's are great people, they don't have an elected president like the Reagan's do, and aren't related unless you go back several generations.

“And I don't know why [Apple is] acting like it’s superior. I don't even get it. What are they trying to say?” -- Bill Gates on the Mac ads
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