fredymac said:
The USAF follows a haphazard and unfocused scramjet technology program because they have secretly achieved hypersonic flight at Area 51 and are trying to fool the world into thinking we are still decades from obtaining an operational capability so as to maximize combat effectiveness should war ever break out.

Or

The USAF follows a haphazard and unfocused scramjet technology program because they are bunch of dithering bureaucrats who actually don’t care and are more interested in office politics.

Tough call but I’m leaning to the later interpretation. I suppose it’s possible it may also be a case of factionalism where some bureaucrats would like to proceed expeditiously while others work to sabotage such efforts since they have pre-determined the technology can’t work, or worse, might work and upset international relationships.

I'm guessing it's a combination of Keystone Cops and "we don't want to scare the other guy into arming up".
 
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.
 
Grey Havoc said:
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.

Yep.
 
Grey Havoc said:
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.
They're spending a whole heap of money explicitly to counter someone they supposedly don't fear.
 
Grey Havoc said:
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.

Show me evidence to support this theory.
 
Moose said:
Grey Havoc said:
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.
They're spending a whole heap of money explicitly to counter someone they supposedly don't fear.

No, they are spending money to permanently cement their newly gained (or in the case of Russia, regained) supremacy over the United States.

Sundog said:
Grey Havoc said:
Unfortunately for the supporters of the latter policy, the 'other guys' are all arming up with abandon, especially since they believe that they don't have anything to fear from the United States.

Show me evidence to support this theory.

:eek:

I would submit that the proof is in the global pudding, so to speak.
 
The X-51 case is going to be a problem, this appears to be the curse of "breakthrough technology" which haunts the US military procurement.

It is quite likely that the X-51 represents an old-fashioned scramjet design in several fundamental areas. With that being the case, it is very easy to imagine somebody telling a USAF general that the AF should move on beyond the X-51. The USAF, seeing the new and more efficient scramjet designs, decides to go with the state-of-the-art instead of advancing an older design. This sounds very reasonable, except for the fact that there is minimal experience in the US flying scramjets. As the basics of the technology does not exist, any advances will still be a fundamental research project.

This is, to abuse the old WW2 parallels, similar to the Me-262 story. Instead of accepting something reasonable now and simultaneously advancing the technology, the USAF is pushing for the advanced technology without any concern for something now. Given that the timeline to an updated scramjet is likely to be around a decade, there is a long time until the USAF gest the capability.

This decade represents a time of US advantage in airbreathing scramjets. Other countries will work on this problem and we have no reason to expect them to take much longer than a decade either to get their capability. The USAF is trading an advantage now for some moderate performance improvement in the future. Even that performance improvement is unlikely to be permanent, as other countries will build off X-51 experience too...

What was that short-story posted yesterday about a space empire which loses a war by constantly pursuing the next technology? That seems to be very pertinent here.
 
DrRansom said:
The X-51 case is going to be a problem, this appears to be the curse of "breakthrough technology" which haunts the US military procurement.

It is quite likely that the X-51 represents an old-fashioned scramjet design in several fundamental areas. With that being the case, it is very easy to imagine somebody telling a USAF general that the AF should move on beyond the X-51. The USAF, seeing the new and more efficient scramjet designs, decides to go with the state-of-the-art instead of advancing an older design. This sounds very reasonable, except for the fact that there is minimal experience in the US flying scramjets. As the basics of the technology does not exist, any advances will still be a fundamental research project.

This is, to abuse the old WW2 parallels, similar to the Me-262 story. Instead of accepting something reasonable now and simultaneously advancing the technology, the USAF is pushing for the advanced technology without any concern for something now. Given that the timeline to an updated scramjet is likely to be around a decade, there is a long time until the USAF gest the capability.

This decade represents a time of US advantage in airbreathing scramjets. Other countries will work on this problem and we have no reason to expect them to take much longer than a decade either to get their capability. The USAF is trading an advantage now for some moderate performance improvement in the future. Even that performance improvement is unlikely to be permanent, as other countries will build off X-51 experience too...

What was that short-story posted yesterday about a space empire which loses a war by constantly pursuing the next technology? That seems to be very pertinent here.

The Me-262 story is instructive in that the Germans could get jet fuel from their abundant brown coal supplies but not high octane gasoline.

The X-51 demonstrated that a hydrocarbon (JP-7) could propel and cool a scramjet. The downside is that there are no volume production JP-7 refineries on Planet Earth.

OTOH, the Air Force buys bulk quantites of RP-2, JP-10, JP-8+100 and JPTS all of which (when used in conjunction with thermal stabilizing additives or onboard treatments) could be suitable scramjet fuels.
 
I seriously doubt that JP-7 production couldn't be scaled enough to support an Initial Operating Capability for hypersonic cruise missiles. Or, at least, an ongoing test program to experiment with different development tool weaknesses.
 
DrRansom said:
I seriously doubt that JP-7 production couldn't be scaled enough to support an Initial Operating Capability for hypersonic cruise missiles. Or, at least, an ongoing test program to experiment with different development tool weaknesses.

This is the same Air Force that spent money to conduct a study to authorize a life extension of JP-10 fuel stocks rather than buying new fuel stock from the world's only JP-10 refinery.
And that's for a fuel that serves other customers (MALD, Tomahawk etc).
 
http://www.airforcetimes.com/story/military/2016/03/01/hypersonics-could-help-us-air-force-thwart-enemy-anti-air-defenses/81156854/

Mitchell Institute download top right "Hypersonic Weapons and US National Security"

http://www.mitchellaerospacepower.org/#!mitchell-studies/k006t
 
http://www.airforcemag.com/MagazineArchive/Magazine%20Documents/2016/March%202016/0316weapons.pdf
 
bobbymike said:
http://www.airforcemag.com/MagazineArchive/Magazine%20Documents/2016/March%202016/0316weapons.pdf

Great post. I especially like the historical milleu.

The 1958 NACA paper (cited above) on Supersonic Combustion Ramjets by Weber and MacKay used an IBM 650 to do the calculations.
An integer multiplication took 13 milliseonds compared to about 1 nanosecond on a modern commodity CPU.
 

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https://info.aiaa.org/Regions/Western/Orange_County/ASAT%20Conference%202014%20Presentations/Jorris_412TW-PA-14077-Hypersonic_Space_Transit_and_Space_Access_Flight_Test.pdf
 
quellish said:
https://info.aiaa.org/Regions/Western/Orange_County/ASAT%20Conference%202014%20Presentations/Jorris_412TW-PA-14077-Hypersonic_Space_Transit_and_Space_Access_Flight_Test.pdf

Thanks. Slide 9 is very illustrative; launching before the JP-7 freezes (higher freezing point than for example JP-8) and before the X-51 avionics overheat.
 
Slides 20, 21, and 22 are interesting. I wonder if they have actual flight test video where the slide shows the "watch" buttons? Those would be very interesting.

Slide 21 isn't fully explained. Is this an example of China translating the slide or re-using the artwork for their own program?
 
Probably pointing to the idea that the Chinese program isn't as real as people think it is. The linked story at the Free Beacon uncritcally accepts as fact the idea that this slide illustrates a Chinese program well in advance of US capabilities.
 
TomS said:
Probably pointing to the idea that the Chinese program isn't as real as people think it is.

It's been flight tested more than the HTV-2 and Army's program combined. Seems pretty real to me.
 
Even if the X-51 was difficult to launch, it still is the only hypersonic flight program. Notable, the Mitchell Institute paper strongly suggests continued development work, not a series of discrete and overly ambitious programs. Stopping X-51 flight tests to wait for the next scramjet falls into that deplorable pattern.


China has active flight tests on Wu-14, US does not actively test army missile and HTV-2 was cancelled (I suspect for good reasons...). I'd say china's hypersonic program is advancing faster than the US.

The overall problem is that nobody has a big lead in hypersonics. The US has two decades lead in stealth and at least a decade lead in turbojets. In hypersonics, the lead is five years in scramjets, negative in ramjets and even to falling behind in gliders. For Russia and China, hypersonics are a very promising area to draw even or ahead of the US.
 
DrRansom said:
China has active flight tests on Wu-14, US does not actively test army missile and HTV-2 was cancelled (I suspect for good reasons...).

One flight was successful and one partially so. I don't know that I'd call that a good reason for cancelling it. (Though in today's risk-averse environment in the west it's par for the course.)
 
http://www.defensenews.com/story/defense/air-space/2016/03/16/lockheeds-marilyn-hewson-touts-breakthroughs-hypersonic-weapons/81836070/

Although it is extremely difficult to reach and maintain such speeds due to extreme temperatures and thermal loadings, the US has had the ability to build boost glide and boost cruise weapons for six decades. NASA’s X-15 effort in the 1960s was able to achieve speeds of Mach 5, and in 2013 the Air Force’s X-51 Waverider air vehicle, launched from a B-52 bomber, reached Mach 5.1 at 60,000 feet
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I've been preaching the "historical" solution just plain old rocket technology to produce a high speed weapon now and R&D on more exotic air-breathers down the road.
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To meet this need, Lockheed is working on a number of innovative technologies to enable long-duration, maneuverable, hypersonic flight, company CEO Marillyn Hewson told reporters March 15. These breakthroughs include new thermal protection systems, innovative aerodynamic shapes, navigation guidance and control improvements, and long-range communication capabilities, she said.

Lockheed has previously supported work on hypersonics. In 2011, a joint Lockheed-Defense Advanced Research Projects Agency effort tested HTV-2, a hypersonic vehicle designed to travel at Mach 20. But the friction and heat burned through the test vehicle’s outer shelf, and it crashed into the Pacific Ocean.

Based on lessons learned from HTV-2, Lockheed is currently supporting two new customer efforts in hypersonics: the Hypersonic Air-breathing Weapon Concept, or HAWC, and the Tactical Boost Glide vehicle, Hewson said.

“The technology could also enable hypersonic passenger flights, and, even easier, access to space,” Hewson said. “I am confident that Lockheed Martin has the technical expertise to make it happen.”

Lockheed’s secretive Skunkworks arms is working with Aerojet Rocketdyne to mature technologies for HAWC, a joint DARPA-US Air Force effort, according to Skunkworks executive vice president Rob Weiss. Lockheed’s HAWC uses a booster to get up to altitude and then fires a “scramjet” engine that funnels in oxygen from the outside air to reach upwards of Mach 5, Weiss said March 15.

Lockheed will submit a proposal later this month, and expects a contract award in the middle of the year, Weiss said. A demonstrator aircraft will fly in the 2018 timeframe, he said.

Lockheed, along with Raytheon, also recently won a contract for the initial phase of the Tactical Boost Glide, another joint DARPA-Air Force program. The TBG is boosted up to high altitudes and speeds over Mach 5, and then glides to its target, Weiss explained.

“We actually feel that we’ve made substantial progress in all the technologies associated with hypersonics,” Weiss said. “There’s a number of challenges in the technologies, the propulsion, the materials that have to deal with the high temperatures, and we’re at a point now where those technologies are mature, and therefore we feel very confident that we can field and successfully fly a hypersonic vehicle.”

Hewson also showed an image of a third hypersonic concept, similar to the HAWC but with a recoverable “turbine-based combined cycle” engine, Weiss explained. The HAWC’s booster is designed for a single use, he stressed. There is not yet a DARPA project for this capability, and Lockheed still needs to mature the propulsion technology, he said.

Such an aircraft could be produced for less than $1 billion, Hewson said.

“Most importantly, we’re proving a hypersonic aircraft can be produced at an affordable price,” Hewson said. “We estimate it will cost less than $1 billion to develop, build and fly a demonstrator aircraft the size of an F-22.”
 
bobbymike said:
http://www.defensenews.com/story/defense/air-space/2016/03/16/lockheeds-marilyn-hewson-touts-breakthroughs-hypersonic-weapons/81836070/

Although it is extremely difficult to reach and maintain such speeds due to extreme temperatures and thermal loadings, the US has had the ability to build boost glide and boost cruise weapons for six decades. NASA’s X-15 effort in the 1960s was able to achieve speeds of Mach 5, and in 2013 the Air Force’s X-51 Waverider air vehicle, launched from a B-52 bomber, reached Mach 5.1 at 60,000 feet
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I've been preaching the "historical" solution just plain old rocket technology to produce a high speed weapon now and R&D on more exotic air-breathers down the road.

I wonder why they didn't mention that the X-15 actually reached Mach 6.7, or why they didn't mention the plain old ramjet powered ASALM reached Mach 5.4. ;) As for using rockets to achieve high speeds in the short term, I'm right there with ya.

https://www.youtube.com/watch?v=UFG-gJcNVGA

https://en.wikipedia.org/wiki/Shaurya_(missile)

Granted, that's a fairly large missile (nearly as big/heavy as a Pershing II), but they'd fit nicely 4 to a tube on an Ohio SSGN, or one or two on a 10-wheel Oshkosh truck.
 
sferrin said:
bobbymike said:
http://www.defensenews.com/story/defense/air-space/2016/03/16/lockheeds-marilyn-hewson-touts-breakthroughs-hypersonic-weapons/81836070/

Although it is extremely difficult to reach and maintain such speeds due to extreme temperatures and thermal loadings, the US has had the ability to build boost glide and boost cruise weapons for six decades. NASA’s X-15 effort in the 1960s was able to achieve speeds of Mach 5, and in 2013 the Air Force’s X-51 Waverider air vehicle, launched from a B-52 bomber, reached Mach 5.1 at 60,000 feet
-----------------------------------------------------------------------------------------------
I've been preaching the "historical" solution just plain old rocket technology to produce a high speed weapon now and R&D on more exotic air-breathers down the road.

I wonder why they didn't mention that the X-15 actually reached Mach 6.7, or why they didn't mention the plain old ramjet powered ASALM reached Mach 5.4. ;) As for using rockets to achieve high speeds in the short term, I'm right there with ya.

https://en.wikipedia.org/wiki/Shaurya_(missile)

Granted, that's a fairly large missile (nearly as big/heavy as a Pershing II), but they'd fit nicely 4 to a tube on an Ohio SSGN, or one or two on a 10-wheel Oshkosh truck.
Or a couple hundred on a converted LHA? :eek:

th
 
sferrin said:
I wonder why they didn't mention that the X-15 actually reached Mach 6.7, or why they didn't mention the plain old ramjet powered ASALM reached Mach 5.4. ;) As for using rockets to achieve high speeds in the short term, I'm right there with ya.

https://www.youtube.com/watch?v=UFG-gJcNVGA

https://en.wikipedia.org/wiki/Shaurya_(missile)

Granted, that's a fairly large missile (nearly as big/heavy as a Pershing II), but they'd fit nicely 4 to a tube on an Ohio SSGN, or one or two on a 10-wheel Oshkosh truck.

Or that Skybolt could reach Mach 15 and was conveniently portable via several hundred off-the-shelf subsonic platforms.
 
Yep. They'd have used the crap out of Skybolts in a conventional role by now.
 
sferrin said:
Yep. They'd have used the crap out of Skybolts in a conventional role by now.
Should there be a thread, probably not because it would get political by necessity of what transpired, called "How the US Gave Away Its' Strategic Advantage By Not Building These Weapons"
 
I would be very surprised if there exists the technology to build a hypersonic vehicle the size of a F-22. From what I know of the field, there are several major theoretical and modeling gaps which have yet to be solved.
 
Did you ever consider that the issue isn't building a vehicle of such speed, but something else? Too many disparaging statements on what we can't do today etc., without even considering what they are actually trying to do. What's the point of comparing a scramjet research vehicle with a glide vehicle, and now apparently ballistic missiles? Other than the usual "lets complain about everything".
 
http://breakingdefense.com/2016/03/3d-printing-key-to-hypersonic-weapons-raytheon/

http://www.raytheon.com/news/feature/3d_printing.html
 
http://www.daytondailynews.com/news/news/local-military/afrl-future-tech-key-to-warfare-strategydrones-las/nq6Nm/
 
bobbymike said:
http://www.daytondailynews.com/news/news/local-military/afrl-future-tech-key-to-warfare-strategydrones-las/nq6Nm/

From this and other articles I've read on this topic recently it sounds like LM are pushing on an open door when it comes to the proposed SR-72.
 
bipa said:
sferrin said:
bipa said:
sferrin: reference about that ASALM Mach 5.6+ flight 30+ years ago ??

It was on one of the USAF research labs sites history section. About 10 years ago. It was a one-paragraph blurb.
http://www.designation-systems.net/dusrm/app4/asalm.html
http://www.secretprojects.co.uk/forum/index.php/topic,466.0.html

If you felt ambitious you could probably dig through the AIAA and Flight International archives to find more information.

Thanks.
I already knew those references, but I have always been skeptical about this story of a vehicle "accidentally" reaching M=5.5 while its design was for M=4 to 4.5, so I was wondering whether you had other references.

http://exrocketman.blogspot.com/2012/08/third-x-51a-scramjet-test-not-successful.html
 
quellish said:
https://info.aiaa.org/Regions/Western/Orange_County/ASAT%20Conference%202014%20Presentations/Jorris_412TW-PA-14077-Hypersonic_Space_Transit_and_Space_Access_Flight_Test.pdf

Interesting how small the B-52/X-51 operational envelope overlap is. It's a shame a few B-58s aren't still around. Even if they got permission to use the external hard points on a B-1B I don't know that it would have been very useful.
 
http://www.defensetech.org/2016/11/09/air-force-seeks-hypersonic-cruise-missiles/?ESRC=dod-bz.nl
 
It's an X-51 ?
 

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A small model of the X-51A on display at the Boeing Future of Flight museum, 28 February 2018.
 

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