Lockheed Martin SR-72?

[flateric]

From May 2009 Skunk Works presentation. HTV-3X/BlackSwift heritage is obvious, as the fact that SR-72 name is truly generic and doesn't belong to specific design

 

[Ronny]

I know it's not popular to mention this but once an ballistic missile is exo-atmospheric it can launch hundreds of decoys (aluminized balloons as there's no air resistance up there) and on the descent phase they've got MIRVs (multiple independently targetable re-entry vehicles) - it's a bit like having a gun to shoot down your enemie's buckshot , but it's damn good business for the defense contractors since it will never be put to the real test.

So Wrong.

On MIRVs:

Multiple Independently-Targeted Re-Entry Vehicles (MIRVs)

Why they exist Although MIRVs are often regarded as a development of MRVs, in fact they come from a totally different logic. In a ballistic missile site, the missile itself represents only a small proportion of the cost of the system (usually 10 - 20 percent). The bulk of that cost is represented by the silo and the command control system that goes with it. That cost is dorectly related to the number of missiles, not the number of warheads on each missile. Therefore, it is much less expensive to built 100 missiles with ten warheads each that 1,000 missiles with one warhead each. All the money saved can be invested in making the silos much harder and thus more difficult to destroy (meaning the enemy must fire more missiles at them to guarantee their destruction).

How it works The missile bus containing the warheads is designed so that it can make changes in its attitude and pitch between discharging warheads. It is then programmed so that, at the appropriate time, it can make those changes before discharging a warhead and can, thus, aim each warhead at a separate target. In theory it can aim all its warheads at different targets, in reality things are much more complex.

The problem is that the system has to discharge its warheads one at a time. It cannot discharge the whole lot at once. This puts a limit on how many it can discharge in the time available. Also, the degree of manoeuvering is strictly limited. So, the targets engaged by a single MIRV missile are limited toa relatively restricted footprint. Also, there are a lot more variable, many random and unpredictable, in aiming and discharging the MIRV bus which mean that MIRV missile-delivered RVs are a LOT less accurate than unitary RVs. So much so that if the launch distance is too far back from the target, the MIRVs are likely to miss by so much that they will be useless. So the distance at which the MIRV can discharge is severely limited. It should also be noted that the MIRV bus is very complex and very sensitive.

Effects on ABM MIRVs are also often promoted as a way of beating an ABM defense by "swamping it", apparently on the assumption that each descending RV would have to be destroyed individually. In fact, this is, again, not the case. Using nuclear-tipped ABMs, the relatively tightly clustered MIRVs would be taken out by a single shot. However, the simplest technique of eliminating MIRVs is, once again, to kill the bus before it discharges its warheads. This needs some extended range - the effect of MIRVs on the Nike-Zeus program was to upgrade the Zeus interceptor so that it had the range necessary to kill the MIRV bus before it discharged its warheads. That's why the range was increased from 250km (more than adequate to kill an MRV bus) to 740km (way more than adequate to kill any projected MIRV bus. Also, as a bonus, it needed only tiny amounts of damage or disturbance to render the MIRV bus ineffective. Far from being a way of beating an ABM defense, MIRVs were only credible in the absence of ABMs of adequate range.

and

Put in a nutshell, decoys don't work. That's about as simple as it gets. There are more than three dozen technologies available to distinguise decoys from real warheads. The decoy question was throughly investigated in the early 1960s and all the practical forms of decoy were discounted. By 1964, the decoy problem was essentially solved. Since that time, decoy developers have been trying to produce better decoys and the counter-decoy people have been devising ways of distinguising between the decoys and the real thing. At the moment, the filtration techniques are so far ahead that decoys have been discounted as a viable technique.

To work, a decoy would have to be exactly the same size, shape, weight, weight distribution, appearance, thermal characteristics and thermal distribution as a real warhead; if one's going to do that, why not just use a real warhead? By the way, before anybody repeats the old line "don't make the decoy look like a warhead, make the warhead look like a decoy", that was one of the earliest ideas that was tested. It doesn't work.

The British based an entire Polaris update around the use of decoys (it was called Chevaline). Chevaline ran years late and was horribly over-cost, the problems with the decoys being the primary and largest single cause of the problems. In fact, those problems were never solved. By the way, even using decoys from a ballistic missile is not as easy as it sounds; there's quite a few problems there that have never been solved either. Mostly because it wasn't worth spending money solving those problems when the decoys wouldn't work anyway.

A bit off topic but where did you found that?

 

[Conspirator]

has anyone thought about the compression and air friction heat problem? how would they deal with that? an object traveling at mach 5 would create surface temps of over 1000 deg Celcius....... how would they achieve mach 6.6?? it would practically look like a meteor flying at that speed. if they were able to make it survive. i was thinking like... the bottom material used on the shuttle but lighter and better placed. would that work?

 

[In_A_Dream]

has anyone thought about the compression and air friction heat problem? how would they deal with that? an object traveling at mach 5 would create surface temps of over 1000 deg Celcius....... how would they achieve mach 6.6?? it would practically look like a meteor flying at that speed. if they were able to make it survive. i was thinking like... the bottom material used on the shuttle but lighter and better placed. would that work?

Fly faster where there's less air friction.

 

[_Del_]

It doesn't quite work that way. The same max temperature will eventually be reached for a given shape and velocity. The altitude simply changes the rate of heat transfer. Which is fine and dandy if you are on a terminal flight, or a short duration rocket trip. Quite another when you want to go cruising some distance at Mach 5.

 

[CJGibson]

has anyone thought about the compression and air friction heat problem?

Off and on for the last 70 years. It's called the thermal thicket. That's one of the many reasons it hasn't been done. Oh, and the air doesn't work as advertised above Mach 4.5.

Chris

 

[Archibald]

It doesn't quite work that way. The same max temperature will eventually be reached for a given shape and velocity. The altitude simply changes the rate of heat transfer. Which is fine and dandy if you are on a terminal flight, or a short duration rocket trip. Quite another when you want to go cruising some distance at Mach 5.

What's more: whatever the speed, above 100 000 feet there is no longer enough air to produce any lift. Airbreathing is not possible above that limit. This is known since the 60's, with the subsonic U-2s, RB-57s and the Ryan drones (COMPASS ARROW); and all the Mach 3+ bombers and SR aircraft and proposals.
The highest numbers I've ever seen are Convair ISINGLASS: 110 000 feet and Mach 4.5 - above this, it's "rocket thrust or nothing".

Note that even the faster scramjet proposals - beyond Mach 6 - have difficulties flying at 100 000 feet or above without some kind of rocket boost, small or large.
Horizontal airbreathing flight upper limit still stands at 100 000 ft whatever the vehicle speed.

 

[Hood]

It's called the thermal thicket.

Sounds prickly. Maybe its misdiagnosed prickly heat? *grabs coat*

 

[Deleted member 2278]

Oh, and the air doesn't work as advertised above Mach 4.5.

You have to keep a fairly wary eye on it above Mach 0.9. I'd rather not think what it was getting up to at Mach 4.5!

 

[Archibald]

It's called the thermal thicket.

Sounds prickly. Maybe its misdiagnosed prickly heat? *grabs coat*

You have won a thicket to the door, I would say (grabs my own coat).

 

[kaiserd]

A joke so bad it should be against the rules of the forum…..

 

[Archibald]

Which one ?

 

[UpForce]

You have won a thicket to the door, I would say

Only after having had a few, perhapsh? (Outta my way, I need my coat)

 

[_Del_]

What's more: whatever the speed, above 100 000 feet there is no longer enough air to produce any lift. Airbreathing is not possible above that limit.

Mostly, it's a problem of air for combustion. Because of the great speeds potentially involved, transatmospheric flight at well above that is at least theoretically possible.
Lift increases as the square of velocity. So if we double the velocity from Mach 3 to 6, we get four times at much lift from the wing. The tiny X-43 lofted it up to 110,000 feet. The X-15 used aerodynamic controls up to 150,000 feet, if I remember correctly. The X-30 was aiming for 150,000-200,000 at one point.

Mostly it's thermal management. Both for airframe and engine.

 

[dark sidius]

View: https://www.youtube.com/watch?v=xbqWdXzV-Bk&t=139s

Sr-72 at the end of the video ?

 

[In_A_Dream]

View: https://www.youtube.com/watch?v=xbqWdXzV-Bk&t=139s

Sr-72 at the end of the video ?

Good catch!

 

[UpForce]

Sr-72 at the end of the video ?

Thought it might be as well but was unsure enough not to post about it. Good to know it got others thinking as well.

 

[RavenOne]

View: https://www.youtube.com/watch?v=xbqWdXzV-Bk&t=139s

Sr-72 at the end of the video ?

L-M announces its being developed,front cover of their official Skunk Works book published few years back shows something similar then L-M retracts the statement they are devloping SR-72. There has been sightings of subscale unmanned demonstrator inbound to Palmdale around the same time with T-38 Talon chase plane.

This coupled with N-G recent video of mystery airframe....

Me thinks there is something even more interesting in development and the likes of the B-21, RQ-180 and seceretive next generation fighter that are being slolwy teased to us will be small fry.

Cheers

 

[CJGibson]

Should I be polishing my tyre-kicking shoes?

Chris

 

[Hanz2k]

“…The future is coming at Mach 18?…”

 

[jsport]

includes vid

A recent US Air Force promotional video hints at 2 new secretive spy aircraft

Several interesting projects are featured in a short US Air Force promotional video released this month.

www.businessinsider.com

 

[Colonial-Marine]

While l always appreciated the SR-71 and the A-12 Blackbird for the awesome reconnaissance aircraft they were I was always more intrigued by other perspective uses of the design. The F-12B interceptor almost made it to service but IIRC there was consideration of using the design for the fast delivery of a tactical nuclear weapon or two.

I'm sure the anti-nuke crowd would go ballistic over the idea of using the supposed SR-72 in that role but what else besides for strategic reconnaissance might such an aircraft be used for? Launch aircraft for an anti-satellite missile? suppose the F-15 could do that again if needed though? High priority precision strike?

 

[sferrin]

While l always appreciated the SR-71 and the A-12 Blackbird for the awesome reconnaissance aircraft they were I was always more intrigued by other perspective uses of the design. The F-12B interceptor almost made it to service but IIRC there was consideration of using the design for the fast delivery of a tactical nuclear weapon or two.

I'm sure the anti-nuke crowd would go ballistic over the idea of using the supposed SR-72 in that role but what else besides for strategic reconnaissance might such an aircraft be used for? Launch aircraft for an anti-satellite missile? suppose the F-15 could do that again if needed though? High priority precision strike?

Anti-shipping missions in the Pacific.

 

[_Del_]

Dr. Czysz talked about using such a craft to help close the GIUK gap, as well. Same principle.

 

[RavenOne]

Should I be polishing my tyre-kicking shoes?

Chris

Magic question here, with Top Gun 2 depicting the mythical Aurora could it be a tease for the 72 or whatever it is to be revealed? Pentagon and dept of the navy would not back help out Hollywood this far as if your recall with Independence day, the Pentagon were all up for providing bases , a/c if the producers took Area 51 out of the script but Hollywood Said nope and the Pentagon politely declined.

cheers

 

[Archibald]

Maybe Lockheed is feeling some pressure from that HERMEUS thing ? if an insignificant startup claims "we will beat that old A-12 Mach 3.4 speed record, and also the SR-71 horizontal flight altitude record of 23 km" - maybe Lockheed will react ?

I'm really not a die hard fan of Mach 4+ flight or hypersonics (suborbital skip-glide / boost glide / ricochet is so much easier) but a Hermeus - Lockheed "race to mach 5" would be interesting to watch...

 

[iverson]

While l always appreciated the SR-71 and the A-12 Blackbird for the awesome reconnaissance aircraft they were I was always more intrigued by other perspective uses of the design. The F-12B interceptor almost made it to service but IIRC there was consideration of using the design for the fast delivery of a tactical nuclear weapon or two.

I'm sure the anti-nuke crowd would go ballistic over the idea of using the supposed SR-72 in that role but what else besides for strategic reconnaissance might such an aircraft be used for? Launch aircraft for an anti-satellite missile? suppose the F-15 could do that again if needed though? High priority precision strike?

While this could be apocryphal, I have read that the "SR-" prefix ("Strategic Reconnaissance") originated in the idea of using a larger, two-man, nuclear-capable version of the A-12 as as a sop to US right-wing politicians who were outraged by the cancellation B-70. The proposal called it the "RS-71" (for "Reconnaissance Strike"). But somewhere during the roll-out of the idea, the letters got transposed. The nuclear role was never really practical/serious (heat problems and reduced range, I think, plus the superiority of missiles). The aircraft continued as a reconnaissance airplane.

 

[iverson]

Maybe Lockheed is feeling some pressure from that HERMEUS thing ? if an insignificant startup claims "we will beat that old A-12 Mach 3.4 speed record, and also the SR-71 horizontal flight altitude record of 23 km" - maybe Lockheed will react ?

I'm really not a die hard fan of Mach 4+ flight or hypersonics (suborbital skip-glide / boost glide / ricochet is so much easier) but a Hermeus - Lockheed "race to mach 5" would be interesting to watch...

I can't see who would put up the money for something like this or why. I think that the days of pure prestige technology and records for records' sake are past us, at least for the moment. For anyone to do it, there would have to be a practical requirement that made hypersonics essential. I can't see what that would be.

Reconnaissance is the only plausible mission for such a craft, and it is far from clear that fast manned aircraft are a viable solution. Satellites--even commercial satellites--can provide generally superior recon and sigint coverage now, without the complexities and unknowns of hypersonic flight. On other end of the spectrum, drones can do anything that satellites cannot, without risking a pilot and without incurring the costs that come with even high sonic performance. Stealth is also the fad of the moment and the big consumer of aerospace research and development funding. If stealth turns out to live up to its publicity, then hypersonics are unnecessary and do nothing but make stealthing more difficult.

I think history shows that hypersonics have had their 15 minutes of fame. If manned Mach 4+ aircraft were going to happen, they could have and would have during the Cold War, when there appeared to be a mission for them. The technology was there, if only just--witness the A-12, SR-71, B-70, and MiG-25. But the money was not, simply because no one could see any plausible return on the investment. Demand and answering technologies--military and civilian--have moved on and in new directions.

 

[Archibald]

Maybe Lockheed is feeling some pressure from that HERMEUS thing ? if an insignificant startup claims "we will beat that old A-12 Mach 3.4 speed record, and also the SR-71 horizontal flight altitude record of 23 km" - maybe Lockheed will react ?

I'm really not a die hard fan of Mach 4+ flight or hypersonics (suborbital skip-glide / boost glide / ricochet is so much easier) but a Hermeus - Lockheed "race to mach 5" would be interesting to watch...

I can't see who would put up the money for something like this or why. I think that the days of pure prestige technology and records for records' sake are past us, at least for the moment. For anyone to do it, there would have to be a practical requirement that made hypersonics essential. I can't see what that would be.

Reconnaissance is the only plausible mission for such a craft, and it is far from clear that fast manned aircraft are a viable solution. Satellites--even commercial satellites--can provide generally superior recon and sigint coverage now, without the complexities and unknowns of hypersonic flight. On other end of the spectrum, drones can do anything that satellites cannot, without risking a pilot and without incurring the costs that come with even high sonic performance. Stealth is also the fad of the moment and the big consumer of aerospace research and development funding. If stealth turns out to live up to its publicity, then hypersonics are unnecessary and do nothing but make stealthing more difficult.

I think history shows that hypersonics have had their 15 minutes of fame. If manned Mach 4+ aircraft were going to happen, they could have and would have during the Cold War, when there appeared to be a mission for them. The technology was there, if only just--witness the A-12, SR-71, B-70, and MiG-25. But the money was not, simply because no one could see any plausible return on the investment. Demand and answering technologies--military and civilian--have moved on and in new directions.

Make no mistake, I share the same feelings ... never been convinced by hypersonics (beware in passing, some will tell you it all starts at Mach 6, not Mach 4 - leaving a semantic no man's land between the two speeds... "high supersonics ?" or "low hypersonics" ?

 

[Hydroman]

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

 

[In_A_Dream]

I think what hurts the acceptability of such realities is that many technological breakthroughs have been hidden from the public in the interest of national security.

Your reality is a byproduct of the information you've been exposed to and how you digest that information. Without key knowledge milestones, how would you ever think anyone could achieve X without pushing through Y first?

On July 16th, 1945, the culmination of significant nuclear engineering work resulted in something that no one could of ever thought was possible. Exercise some degree of imaginative extrapolation to consider the possibilities of what we have access to today.

 

[TomS]

While this could be apocryphal, I have read that the "SR-" prefix ("Strategic Reconnaissance") originated in the idea of using a larger, two-man, nuclear-capable version of the A-12 as as a sop to US right-wing politicians who were outraged by the cancellation B-70. The proposal called it the "RS-71" (for "Reconnaissance Strike"). But somewhere during the roll-out of the idea, the letters got transposed. The nuclear role was never really practical/serious (heat problems and reduced range, I think, plus the superiority of missiles). The aircraft continued as a reconnaissance airplane.

It's not hard to find the true version of this story. The SR-71 was designated as RS-71 until just before the public announcement, when the name was swapped at Curtis LeMay's request.

Non-Standard DOD Aircraft Designations

 

[Fluff]

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

I'm hoping for giant jet propelled Airships, launching manned hypersonic strike aircraft.

 

[Archibald]

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

I'm hoping for giant jet propelled Airships, launching manned hypersonic strike aircraft.

(I've posted this silly thing way too often, I know...)

View: https://www.youtube.com/watch?v=E7W9a9tNhvA

 

[Hydroman]

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

I'm hoping for giant jet propelled Airships, launching manned hypersonic strike aircraft.

The individuals who know are the individuals cleared and have access to the work the programs.

 

[iverson]

I think what hurts the acceptability of such realities is that many technological breakthroughs have been hidden from the public in the interest of national security.

Your reality is a byproduct of the information you've been exposed to and how you digest that information. Without key knowledge milestones, how would you ever think anyone could achieve X without pushing through Y first?

On July 16th, 1945, the culmination of significant nuclear engineering work resulted in something that no one could of ever thought was possible. Exercise some degree of imaginative extrapolation to consider the possibilities of what we have access to today.

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

You both raise two points: that the secrecy of the project may mean that reality is different than I imagine and that technologies must be implemented in order to advance to future technologies. Let's call the latter the "march of technology" argument.

[1] Secrecy:

Secrecy does not just hide advances. More often, it hides bad decisions and corruption that might otherwise create scandal and protects the careers of the military and political leaders that made them. It hides projects from critical eyes and thus facilitates long, pointless excursions down technological rabbit holes, like Teller's notorious X-ray laser. It can even help to smother a promising but organizationally unpopular technology. Often, in fact, it serves mainly to keep those who have the authority to cut off funding and punish corruption (notably one's own voters or superior officers) from knowing enough to do so. The survival of the F-35 in the face of all of its design compromises, developmental problems, costing scandals may well prove to be a case where secrecy merely protected profits and careers. Or it may not. As long as details are secret, we cannot draw reliable conclusions either way.

In any case, secrecy does not generally (if ever) hide major advances. At its best, secrecy hides critical, non-obvious implementation details from an external enemy. But even then, it can't hide the the nature of a technology or the existence of a program. The existence of stealth programs were fairly well known before the F-117 was revealed and the outlines of the possible technical approaches had been known since WW2. The nuclear bomb is even a better example. The Manhattan Project was probably the most secure possible in modern history. But it could not hide the existence of the project itself or of the technology pursued from enemies. Both Japan and Germany had active programs. Happily, secrecy was just enough to keep them from finding out exactly how the bomb was put together.

Most importantly, though, the secrecy argument in this case requires us to assume facts not in evidence, essentially on faith, simply because doing so facilitates belief in a technological advance regarded as a necessary and inevitable next step.

[2] The March of Technology

The fallacy in the "march of technology" argument is the unstated assumption that technology Y is an inevitable, necessary, natural, first "step" on the way to a predestined technology X. This is a teleological argument: it assumes that historically observed changes are expressions of a purpose and direction inherent in the sequence of events themselves. The classic example of this is the seed that implicitly "contains" the full grown flower. Under this argument, every step in the process of germination, flowering, pollination, fruiting, and going to seed serves the "purpose" of producing the flower. Biology does not, of course, show much sign of actually working this way, no matter how much Hegel and the German Romantic philosophers would like it to. The "purpose" of the seed, the fruit, and the seedling is very much in the eye of the beholder, who in their case simply happens to value flowers more than seeds or fruit or seedlings.

If anything, the history of technology gives even less evidence of "necessary" steps or stages and none whatsoever of any goal towards which technology is striving, speed-based or otherwise. In engineering, requirements drive technology, not vice versa. China had the oil well and the blast furnace--everything needed for an industrial revolution--in 500 BC. But they were drilling for salt, rather than oil (which was a waste product), and casting iron bowls, rather than engine blocks, per the requirements of the time. Subsonics, supersonics, and hypersonics are, like blast furnaces and deep drilling rigs, just techniques. How and when they develop depends on the people that implement them and their requirements, not on their inherent nature or some supposed march of time.

Supersonic engines and airplanes came about because of the need to fly higher and faster in WW2. But requirements changed. Once air forces had supersonic planes, they faced a new set of realities and trade-offs. First, contemporary surface-to-air missiles could always go higher and faster than airplanes. So bombers had to fly low, where the air was thick and turbulent and where supersonic speed only hurt your kidneys made it harder not to hit the ground. Mach 0.9 or less was ideal. Fighters that could reach Mach 2.2-2.5 seldom did in service and never in actual combat, where difficulties identifying and engaging a maneuvering enemy made excess speed a handicap. So fourth-generation fighters were designed to be slower and more maneuverable. Mach 1.8 became more or less the norm. After some trials, commercial aviation also found supersonics not worth the tradeoffs and settled on something like Mach 0.8-0.9 as the optimum.

The SR-71 and the Mach-3 generation arrived during this shift in requirements, just as it became clear that there was nothing for them to do: No fleets of Mach 3 bombers to intercept over the Pole. No denied territory to fly over with impunity. Attempts were made to adapt them to the new requirements--notably the M-12/D-12 drone program--but it was quickly seen that the old design was not compatible with the new needs. These aircraft ended their days prematurely in various research programs. So while we undoubtedly could fly faster than the SR-71 now. Why would we want to? Just being able to do it is not a reason.

[3] Conclusion

The totality of the evidence--what is known not merely conjectured--is that there are no secret hypersonic airplanes. History indicates that there has been no requirement for a successor to the SR-71 in the subsequent 40-50 years. There are lots of requirements for other things. But not that. So, unless someone can articulate an unsatisfied need that SR-72/Aurora/?? addresses, show how the cost/benefit ratios work out when meeting that need, and then show signs that budgeting or sourcing indicate implementation, I remain skepical.

 

[iverson]

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

I'm hoping for giant jet propelled Airships, launching manned hypersonic strike aircraft.

Actually, nowadays, my requirements run more towards giant electric airships with deck chairs and no cell coverage. Quiet. Restful. Slow. Plenty of fresh air. Plenty of naps.

 

[Fluff]

I think what hurts the acceptability of such realities is that many technological breakthroughs have been hidden from the public in the interest of national security.

Your reality is a byproduct of the information you've been exposed to and how you digest that information. Without key knowledge milestones, how would you ever think anyone could achieve X without pushing through Y first?

On July 16th, 1945, the culmination of significant nuclear engineering work resulted in something that no one could of ever thought was possible. Exercise some degree of imaginative extrapolation to consider the possibilities of what we have access to today.

In my opinion, if we could fly the Blackbird family at Mach 3+ in the early 1960's, I'm sure we can fly much faster now, just sensitive programs and technology. Remember, Have Blue, Tacit Blue and F-117 were rumors, kept highly classified then saw the light of day eventually.

You both raise two points: that the secrecy of the project may mean that reality is different than I imagine and that technologies must be implemented in order to advance to future technologies. Let's call the latter the "march of technology" argument.

[1] Secrecy:

Secrecy does not just hide advances. More often, it hides bad decisions and corruption that might otherwise create scandal and protects the careers of the military and political leaders that made them. It hides projects from critical eyes and thus facilitates long, pointless excursions down technological rabbit holes, like Teller's notorious X-ray laser. It can even help to smother a promising but organizationally unpopular technology. Often, in fact, it serves mainly to keep those who have the authority to cut off funding and punish corruption (notably one's own voters or superior officers) from knowing enough to do so. The survival of the F-35 in the face of all of its design compromises, developmental problems, costing scandals may well prove to be a case where secrecy merely protected profits and careers. Or it may not. As long as details are secret, we cannot draw reliable conclusions either way.

In any case, secrecy does not generally (if ever) hide major advances. At its best, secrecy hides critical, non-obvious implementation details from an external enemy. But even then, it can't hide the the nature of a technology or the existence of a program. The existence of stealth programs were fairly well known before the F-117 was revealed and the outlines of the possible technical approaches had been known since WW2. The nuclear bomb is even a better example. The Manhattan Project was probably the most secure possible in modern history. But it could not hide the existence of the project itself or of the technology pursued from enemies. Both Japan and Germany had active programs. Happily, secrecy was just enough to keep them from finding out exactly how the bomb was put together.

Most importantly, though, the secrecy argument in this case requires us to assume facts not in evidence, essentially on faith, simply because doing so facilitates belief in a technological advance regarded as a necessary and inevitable next step.

[2] The March of Technology

The fallacy in the "march of technology" argument is the unstated assumption that technology Y is an inevitable, necessary, natural, first "step" on the way to a predestined technology X. This is a teleological argument: it assumes that historically observed changes are expressions of a purpose and direction inherent in the sequence of events themselves. The classic example of this is the seed that implicitly "contains" the full grown flower. Under this argument, every step in the process of germination, flowering, pollination, fruiting, and going to seed serves the "purpose" of producing the flower. Biology does not, of course, show much sign of actually working this way, no matter how much Hegel and the German Romantic philosophers would like it to. The "purpose" of the seed, the fruit, and the seedling is very much in the eye of the beholder, who in their case simply happens to value flowers more than seeds or fruit or seedlings.

If anything, the history of technology gives even less evidence of "necessary" steps or stages and none whatsoever of any goal towards which technology is striving, speed-based or otherwise. In engineering, requirements drive technology, not vice versa. China had the oil well and the blast furnace--everything needed for an industrial revolution--in 500 BC. But they were drilling for salt, rather than oil (which was a waste product), and casting iron bowls, rather than engine blocks, per the requirements of the time. Subsonics, supersonics, and hypersonics are, like blast furnaces and deep drilling rigs, just techniques. How and when they develop depends on the people that implement them and their requirements, not on their inherent nature or some supposed march of time.

Supersonic engines and airplanes came about because of the need to fly higher and faster in WW2. But requirements changed. Once air forces had supersonic planes, they faced a new set of realities and trade-offs. First, contemporary surface-to-air missiles could always go higher and faster than airplanes. So bombers had to fly low, where the air was thick and turbulent and where supersonic speed only hurt your kidneys made it harder not to hit the ground. Mach 0.9 or less was ideal. Fighters that could reach Mach 2.2-2.5 seldom did in service and never in actual combat, where difficulties identifying and engaging a maneuvering enemy made excess speed a handicap. So fourth-generation fighters were designed to be slower and more maneuverable. Mach 1.8 became more or less the norm. After some trials, commercial aviation also found supersonics not worth the tradeoffs and settled on something like Mach 0.8-0.9 as the optimum.

The SR-71 and the Mach-3 generation arrived during this shift in requirements, just as it became clear that there was nothing for them to do: No fleets of Mach 3 bombers to intercept over the Pole. No denied territory to fly over with impunity. Attempts were made to adapt them to the new requirements--notably the M-12/D-12 drone program--but it was quickly seen that the old design was not compatible with the new needs. These aircraft ended their days prematurely in various research programs. So while we undoubtedly could fly faster than the SR-71 now. Why would we want to? Just being able to do it is not a reason.

[3] Conclusion

The totality of the evidence--what is known not merely conjectured--is that there are no secret hypersonic airplanes. History indicates that there has been no requirement for a successor to the SR-71 in the subsequent 40-50 years. There are lots of requirements for other things. But not that. So, unless someone can articulate an unsatisfied need that SR-72/Aurora/?? addresses, show how the cost/benefit ratios work out when meeting that need, and then show signs that budgeting or sourcing indicate implementation, I remain skepical.

Yes, but, as the great Donald made clear, there are known knowns, and known unknowns, but there are also unknown unknowns, so just because there shouldn’t be a Mach 5 program, doesn’t mean there wasn’t.

Simulators could allow just a couple of test flights, then bury 30 of them in the Nevada deserts, just In case.

Let’s be careful out there….

 

[In_A_Dream]

[3] Conclusion

The totality of the evidence--what is known not merely conjectured--is that there are no secret hypersonic airplanes. History indicates that there has been no requirement for a successor to the SR-71 in the subsequent 40-50 years. There are lots of requirements for other things. But not that. So, unless someone can articulate an unsatisfied need that SR-72/Aurora/?? addresses, show how the cost/benefit ratios work out when meeting that need, and then show signs that budgeting or sourcing indicate implementation, I remain skepical.

It's good to be skeptical and you are right, there are no officially recognized programs that operate hypersonic aircraft for both the DOD or Intelligence Community.

But there is always a need for time-sensitive ISR, ISR that doesn't always include photo-reconnaissance. And in the interest of major national security priorities, cost/benefit analysis is what you do for programs to decide whether they need a black budget or not.

 

[iverson]

[3] Conclusion

The totality of the evidence--what is known not merely conjectured--is that there are no secret hypersonic airplanes. History indicates that there has been no requirement for a successor to the SR-71 in the subsequent 40-50 years. There are lots of requirements for other things. But not that. So, unless someone can articulate an unsatisfied need that SR-72/Aurora/?? addresses, show how the cost/benefit ratios work out when meeting that need, and then show signs that budgeting or sourcing indicate implementation, I remain skepical.

It's good to be skeptical and you are right, there are no officially recognized programs that operate hypersonic aircraft for both the DOD or Intelligence Community.

But there is always a need for time-sensitive ISR, ISR that doesn't always include photo-reconnaissance. And in the interest of major national security priorities, cost/benefit analysis is what you do for programs to decide whether they need a black budget or not.

Agreed. But satellite coverage is not what it was even a decade ago. It is getting close to continuous and omnipresent. Commercial imagery satellites pass over pretty much every part of the world ever day now and have the ability to reposition themselves for customers that will pay. And customers will. Vast amounts of online and new-agency imagery are now available free or at nominal cost because the data was gathered while a satellite was in transit to a job for a deep-pocketed customer. So even much of the time-sensitive strategic intelligence gathering can be done from orbit, with none of the dangers of overflight.

In addition, the nature of intelligence gathering has, I suspect, shifted, given modern communications. Processing open-source data alone is probably a major task. Much more resources probably go into communications and network surveillance now. With care, it can be done covertly and remotely. When its clumsy, the blowback still seems less erious than a downed plane. When you can listen to, record, and photograph leadership simply by activating favorite telephones that they carry with them and can disable a secret nuclear facility by putting a virus on an entire nation's home computers, you have less need for overflights. What few requirements that remain then have to justify their costs that much more.