back to article Hypersonic plane project confirmed by DARPA

The US Air Force (USAF) has inked a deal with DARPA* - the famously luncheoning-elsewhere Pentagon boffinry outfit - to collaborate on a "combined cycle hypersonic vehicle that could take off and land like a plane", according to reports. Rumours and whispers of a secret American hypersonic aircraft have, of course, been kicking …

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ICBM?

"As an alternative to spyplane work, a Blackswift hypersonic bomber could offer the ability to strike anywhere in the world at fairly short notice, but then so does an existing ICBM."

I suspect you've missed the point here. The only use the US has for ICBMs is to deliver strategic nuke - you know, city killers - not conventional weapons or tactical strike weapons. Cruise missiles can deliver conventional or nuclear strikes in a tactical role, typically being launched from very close to theatre. The reason the US keeps trying to develop aircraft like this is because they only have the blanket option of the ICBM or the in-theatre option of the cruise missile. A hypothetical super-fast jet could deliver a tactical weapon, such as a bunker buster, to a target from the other side of the planet with the added advantage of being able to re-assign its target en-route, which can't be done with a cruise missile.

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Problems with ICBMs

Is that they pop up on radars of countries like China, Russia, India and Pakistan making them all nervous that they're about to be wiped out in a thermonuclear barbecue.

Some of these countries have such poor command and control systems that the threshold for them to launch their own missiles at the enemy du jour is very low. By the time they realise the American missile was actually heading somewhere else, they've inadvertently started a nuclear war.

Which would be a bad thing.

This was the reason the Pentagon recently shelved plans to refit Trident missiles with conventional warheads.

A hypersonic bomber (how Gerry Anderson is that???) won't risk us all developing body cancer when Hillary Clinton's successor decides to bomb a random country in Central Asia.

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Stealthiness not an issue

Once it was built, no-one cared if the Blackbird was stealthy or not. Initially they tried to make it radar-stealthy, but they forgot that two stonking great engines made it the biggest heat source around!

Part of the reason for stealth would be deniability. But if you get to the point where you want to use a Blackbird, you're probably already at war with the country concerned. Or if it's peace-time then you're using it for detailed info on ship/plane movements *and* to send a message to their owner saying "I know where your fleet is, so don't try any funny stuff" - in which case stealth would erase one benefit (the "now you know that I know" part).

The other part, of course, is protection from being shot down. But at the speed the Blackbird travels (or "travelled" if they've really stopped using it), this was never an issue. Remember that it was originally fitted with a small cannon, but that was removed later because they realised the plane would catch up with its own shells! If anyone shot at them, they simply hit the throttle and outran the missile.

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Stealthy or not?

"Being very fast, very hot, very high and made of exotic refractory material, it won't be at all stealthy - which could limit its usefulness as a spy plane."

This is essentially irrelevant. As Bill Sweetman points out in the article you linked to, anything travelling at Mach 6.5 and 100k ft is going to be an absolute sod to hit with a SAM, and no fighter is ever going to be able to get close to that. A degree of stealth shouldn't be ruled out either - the SR-71 had a greatly reduced radar signature through clever construction, despite its extreme performance envelope. Not enough to be deemed truly stealthy perhaps, but certainly enough to make the defender's job even tougher.

Mike

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There is a very valuable niche for a non-ICBM weapon with near ICBM world-wide reach & speed

The first two comments about ICBMs above are valid. There are treaties which limit the ability to use non-nuclear tipped ICBMs - mainly they have to count the same as nuclear tipped ICBMs against nuclear stockpile limits as there is no way short of detonation to distinguish between them.

Prior to World War II, there were treaties in place between the major powers limiting the building of battle ships, because in WW I and earlier, battle ships were the epitome of naval power. Japan & the US built many aircraft carriers just prior to WWII as these were not covered by treaties, and as everyone saw in WWII, aircraft carriers made battle ships look like row boats.

There is a very valuable niche for a non-ICBM weapon with near ICBM world-wide reach & speed. Such a weapon would have as large of an impact on air power as the aircraft carrier had on naval power.

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Anonymous Coward

Ever hear of the XB-70????

Folks,

For what it is worth, the XB-70 (predecessor of the Concord) was a supersonic bomber developed in the 50's. See the link below.

http://www.unrealaircraft.com/classics/xb70.php

My dad worked for a company that was researching the possibility of combined cycle scramjet capability for this aircraft, using a rather unstable radioactive liquid oxidizer call uranium pentoxide. Oxidizers (usually used in liquid fueled rockets) are helpful for high speed flight in oxygen starved atmosphere 70,000 ft or higher. Just close off the air intake and inject them into the turbine with the fuel, kind of like NOS injection in sports cars. Uranium Pentoxide has alot of oxygen contained in a relatively small molecule.

The fuel was NOT liquid hydrogen, but standard jet fuel which has more btu's per (American) gallon than hydrogen and does not require the special handling, cryogenics and compression of LH.

Testing of this engine system was minimal due to the lovely "glow" it produced. Talk about potential for global warming, eh?

Strangely enough, this aircraft would have been capable of "sub-orbital" flight in the mid 70's. Only DARPA and the NSA know, and they can't tell or they'd have to kill you.

The XB-70 "Valkyrie" never made it into battle, only a few planes were built.

I guess the French bought the plans and "developed" the Concord (Flamebait).

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XB70

That's a *very* unusual view of the SST development, which I rather feel could only have come from a citizen of the USA. Although its true that the Concord shares many design features with the XB70. After all from what I can see only the engines, the aerodynamics, the control surfaces, the engine layout and a few other minor features are radically different... But it is true that one of each crashed and both projects were exceedingly late getting to first flight.

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Anonymous Coward

@flamebait

"I guess the French bought the plans and "developed" the Concord" ....

Nooo - the plans were stolen by the villains at Ferrari, with the aid of the evil FIA. How did they get from Italy to France ? well we all know that all of "old europe" are one and the same country !

ps I assume that the French input to the concorde was the non-Lucas electrics, while the English contributed in-flight meals.

..coat, hat, door

Adrian

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Anonymous Coward

Re: XB70

>more btu's per (American) gallon

Does it matter what gallon you're using?

>I guess the French bought the plans and "developed" the Concord

Everyone knows that Concord was copied from the Tu-144

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Complicated SR-71 operations?

"SR-71 operations were actually highly involved, requiring a two-day lead in and multiple prearranged air-to-air refuellings"

You're not kidding. AFAIK, the thermal expansion of the plane at it's maximum performance meant that when the thing was stationary on the ground, its parts contracted so that nothing was sealed anymore. Fully fueled on the ground, it leaked like a sieve - by the time it took off and reached reasonable altitude it needed an air-to-air refuelling almost immediately to carry on. Mind you, once up to speed, it had a rather good fuel economy.

But hell, I still love that plane. Can't believe it first flew in the 60's! Anyone know of a good flight sim featuring it?...

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Anonymous Coward

History...

"I guess the French bought the plans and "developed" the Concord (Flamebait)."

The original design came from the Canadian cf-105 Avro Arrow. When the project was cancelled, it's designers went to different directions. Some went to france and made the concorde, some went to nasa and worked on the apollo and some went and designed the blackbird.

Btw, you could build a simple hypersonic combined cycle (ram/scram/rocket) engine based the original Argus As 014 concept. (well known from the WW2 V-1 flying bombs) It's noisy but cheap, low weight and could switch between operation modes based on the average pressure differene between the intake and the combustion chamber.

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The U-2 proved more useful - feed the flames!

The US binned the SR-71A but kept the developed U-2 instead. The reasons were that the U-2 didn't attract as much attention in operation, was a darn sight cheaper to operate, and could be flown off USN aircraft carriers for true global reach. An added bouns was that it could be modified relatively easily with add-on recce pods to suit the tactical recce role as well, whereas any change to the SR-71A was a major redesign exercise.

The Valkyrie was a technical step too far, where the Americans were unable to create what they thought they needed. Interestingly, the Soviets used pretty simple brute-force tech in the MiG-25 Foxbat to get perfromance that would have rendered the Valkyrie pretty ineffective anyway.

In comparison, Concorde was a technical success, and it used a lot of knowledge gleaned from the TSR.2 program and nothing to do with the Valkyrie failure. The TSR.2 was also a major technical success and would have been largely immune to the MiG-25 (the TSR.2 was designed to operate at very low level below the MiG's radar), but it didn't need the Soviets to kill it, just moronic politicians like Duncan Sandys and the interference of the F-111 salesteam.

The General Dynamics salesteam (led by Lord Mountbatten in the UK!) managed to convince governments that the F-111 (another US aircraft that didn't deliver) was a cheaper and better option. The Australians fell for it hook, line and sinker, and had to wait years to get an aircraft that was half as good as the TSR.2. The British Government gave up on waiting and the RAF eventually used subsonic Blackburn Buccaneers (which regularly scored higher than F-111s on NATO Red Flag exercises).

For recon, the RAF just carried on (and still uses) modified Canberras, not bothering with the U-2 or the SR-71A. Actually, the Canberra was so good it was license-built by Martin as th B-57 and much used by the USAF in Vietnam (and the Australians, who were still waiting for the F-111 to work....).

So, I make that a clean sweep for the British aircraft industry over the best efforts of the Yanks! :P

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Anonymous Coward

XB70 Flamebait works...

Folks, Where is your sense of humor?

In reply to all who took the bait.

The (American gallon) comment was due to the excessive "units of measurement" threads. Gotta define your units of measurement on this site or your worth could be related to "Bulgarian Airbags" in some way!

Yes, I am a bloody Yank. And that matters why? (Obvious Flamebait)

Did anybody actually try the link I included? Does the XB-70 NOT look to be 90% of a Concorde? That it flew in 1962-3 not early enough? That it flew BEFORE the TU-144 not enough? Ever hear of cold war espionage?

The US Military had a policy of leaking unsuccessful project data to the Russians for years (if for nothing else to find internal leaks). The end result was the collapse of the Soviet Union due to their playing "catchup with the Joneses".

BTW the CF-105 Avro Arrow was a delta wing 2 engine interceptor, NOT a colossal bomber like the XB-70 or the TU-144. The only thing the Avro Arrow had in common with the Concorde is the wing shape and we have the Germans to thank for that (and entire space programs of every country).

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Try looking for Westland Pteradactyl or Curtiss-Wright XP-55 amongst others....

The XB-70 looks nothing like Concorde. The Tu-144 "Concordski" used stolen technology which the Tupolev design team didn't really understand, hence the poor fuel efficiency and poor structural strength. The latter resulted in the -1G failure at Le Bourget, an incident that even the Russians admit Concorde would have survived without breakup.

Even before WW2 was over, American politicians were trying to create the myth of the German Uberscientist in an attempt to excuse the perceived quality gap between some of the desperate designs the Germans tried over the efficient designs of the Allies. In reality, deltas and tailess designs were around before the Lippisch work, and rocket and jet technology also. Whilst the American aircraft industry had little interest in deltas and therefore found the German work fascinating, there was plenty of prior work in Europe, some dating back to the 17th century!

Yes, the majority of the US space program early on concentrated on development of the German V2 as a launch platform design, but a lot of the theory the Germans used was based on work pre-dating the War and from many origins (even American!). The wasteful, desperate hunt for superweapons was one of the factors in the fall of the Third Reich, whilst the Allies concentrated on realistic projects leading to solutions like the atom bomb. Britain and most of Europe was too poor to really push space programs after WW2, it had nothing to do with a lack of knowledge.

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Back to those ICBMs...

Using an ICBM to service bomber-type targets is, as already noted, politically insensitive and inflammatory, it's also *really* inefficient, and surprisingly inaccurate in today's world. ICBMs loft about 1000x the mass of the warhead itself to get the warhead where it's going, can only be used once, have CEPs measuring from score to hundreds of feet, and can only service a maximum of ten targets per launch. Further, they're fire-and-forget, and cannot be retargeted or recalled once you push the button.

A bomber re-uses most of the delivery platform over and over and over again, can service many, many targets (depending on load out) per run, can load a mix of munitions for a variety of targets or for a variety of options for the same target, and can deliver everything from dumb gravity bombs to precision laser/GPS/thermal homing weapons with CEPs measuring from tens of feet to fractions of feet. In addition, bombers can be *retargeted* in mid-flight, can loiter looking or waiting for a target, can be *recalled* in mid-flight, and are in all ways vastly more flexible (and less expensive, in the long run) than the inflammatory and provocative ICBMs.

The chief advantage the ICBM has is speed of delivery, and a MACH 6+ bomber removes much of that advantage.

That the author actually suggested such a use for ICBMs suggests a profound lack of critical thinking and/or a profound lack of understanding of the subject.

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