ASALM

DSE said:
sferrin said:
Boy, you certainly don't read about high speed airbreathing programs being that successful today, even with our fancy computers, CFD, "experience" etc. A shame. In hindsight, given the timeframe, I'm wondering if maybe they were thinking about stealth aircraft dealing with SUAWACS instead.

While there have been programs which faltered, I think the two NASA programs, Hyper-X and HiFIRE-2(partnered with AFRL), would be thought of as successes in this light, no?

Do you really want me to list all the failed/cancelled programs that should have been slam dunks, or at the very least, doable had they stuck it out instead of quitting?
 
Puttering around last night. . .


Not sure what's going on in the circled area below. As you can see, they'd already planned on using the MK72 booster to launch the thing. At first I thought they'd just stretched the ASALM design for LRASM-B to maximize the volume usage of a Mk41 cell but in the shot below the "stretch" almost looks like a separate module. ???



(Anybody else wondering if maybe PTV/ASALM/SLAT/LRASM-B topics ought to be combined?)
 

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The VLS-compatible LRASM-B was maxing out the launch cell, they had to shrink the diameter of the weapon in that area to fit the folding fins against the airframe.
 
Thought I posted this but apparently not:

http://exrocketman.blogspot.com/2012/08/third-x-51a-scramjet-test-not-successful.html

"Back about 1980, a technology-demonstrator flight test vehicle called ASALM-PTV accidentally accelerated to Mach 6 at 20,000 feet on its very first flight test. This was due to a fuel control “failure” that was nothing but a stupid assembly error, there was nothing really wrong with the design. It was only designed to cruise at Mach 4, and to power-dive at Mach 5. The other 6 flights were perfect. Its design mission was as a cruise missile effectively invulnerable to defense: subsonic launch, supersonic climb to 80,000 feet (24 km), pullover and accelerate to a Mach 4 cruise, then suddenly dive at Mach 5 onto target.

ASALM was not scramjet at all, it was just an ordinary subsonic combustion ramjet, with part of its technological roots dating all the way back to World War 2. It had a supersonic inlet, a large but mild-expansion nozzle, and a dump combustor for its flame stabilization. It was fueled with RJ-5, a synthetic strongly resembling kerosene.

Unlike the two scramjets, ASALM had an “integral booster” packaged entirely within its engine, not a huge booster stage out behind, to be dropped off. The takeover Mach number with ASALM was Mach 2.5, so the booster could be much smaller in any event.

It was not a waverider, but it did fly on supersonic body lift without any wings. ASALM had a very clean, low-drag "dart" shape, which is a part of how it accidentally reached Mach 6 in that runaway test flight.

I got to work on several related technology projects associated with ASALM, and to participate in the engineering done around the booster inside that combustor. A lot of the same technology went into other ramjet engines I worked on.

The NASA X-43A guys named ASALM as the setter of the record they finally broke in 2004, but they didn't know what ASALM was, or what kind of engine it had. I guess they were just too young: ASALM was well before their time.

Opinion

USAF's design mission for that scramjet missile technology could be done easier, cheaper, and "right now" by marrying existing ICBM technology with existing ramjet cruise missile technology (like ASALM). Put your supersonic ramjet cruise missile inside a re-entry shroud, and stick that on top of an ordinary ICBM. Flight time is 17 minutes to the other side of the world, then you cruise to target in the Mach 3 to 4 range, at around 60-80,000 feet, and finally you dive onto your target at around Mach 5 to 6. If you are attacking fixed geographic coordinates, there is not time for simple inertial guidance to drift.

As I said before, simple. Easy. Cheap.

My question to USAF is: why cruise hypersonic down in the air with all that friction heat and shock loss nonsense, when you don't have to? Actually, the very same question applies to supersonic/hypersonic transport aircraft proposals, too."
 
sferrin said:
USAF's design mission for that scramjet missile technology could be done easier, cheaper, and "right now" by marrying existing ICBM technology with existing ramjet cruise missile technology (like ASALM). Put your supersonic ramjet cruise missile inside a re-entry shroud, and stick that on top of an ordinary ICBM. Flight time is 17 minutes to the other side of the world, then you cruise to target in the Mach 3 to 4 range, at around 60-80,000 feet, and finally you dive onto your target at around Mach 5 to 6. If you are attacking fixed geographic coordinates, there is not time for simple inertial guidance to drift.
sferrin said:

My question to USAF is: why cruise hypersonic down in the air with all that friction heat and shock loss nonsense, when you don't have to? Actually, the very same question applies to supersonic/hypersonic transport aircraft proposals, too."



So instead the author is proposing to go down in the air with all the friction and heat and shock *at over Mach 20* to decelerate to Mach 4? And then start an air breathing engine which would then have to accelerate to Mach 5?


I am not seeing how this is cheaper, easier, or more effective.


ASALM-PTV was propulsion risk reduction - it was very limited in scope. The ASALM program itself had a number of technical risks associated with it, propulsion was only one of them. At the time ASALM was cancelled it was competing for missions with high profile programs - the little missile was a threat to the ATB and ATF programs.
When it was later resurrected as a target with more limited technical requirements it still had plenty of problems and was not fielded.
 
And they were still scared of it when they (briefly) tried to resurrect it again as LRASM-B. One can't help but wonder what the problem is, given that at least it's propulsion seems to work. Considering the trouble they've had getting any kind of supersonic airbreathing missile to work I'd think that would be a huge plus. (RATTLRS and HyFly, seem to have been failures and even X-51 could barely be considered a "success".)
 
George Allegrezza said:
I do agree with the idea that trying to integrate a propulsion system in a ballistic/glide vehicle adds a lot of unwanted complexity. There’s a lot of energy in ballistic or boost-glide profiles that can be exploited without trying to start an RJ at the far end of the trajectory. Way off topic from ASALM, but in “Lightning Bugs”, William Yengst describes the McDonnell 122E BGRV as having 4000 mi range, or up to 2000 mi cross-range capability, at 110-130,000 ft, with low-level run-in at 100ish ft AGL at Mach 5 for the final 50 miles of flight. Of course, the BGRV was launched by an Atlas F, and was a 2500-3000 lb. vehicle with a water-cooled nose cap and all sorts of other exotica, so it’s not totally relevant to the intermediate-range and tactical-range needs in the western Pacific.

Rockets and subsonic ramjets provide a lot of attractive options in this class of weapons, and scramjets are an attractive but very difficult-to-achieve vision that stubbornly seems to remain well down the TRL list. Hopefully we are reaching the point where we realize we have to proceed with achievable hypersonic systems rather than waiting for the scramjet nirvana to arrive. Maybe the TBG guys are thinking along these lines.

I suppose if I were running for office, my defense policy bumper sticker would read “500 bombers, 200 subs, and Skybolts for everyone.”

I'm starting an exploratory committee for your election. ;D
 
Enjoy!
 

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Advanced version of Martin Marietta ASALM designed by
Martin Hollmann.

The center section of the advanced air launched cruise missile was design by Hollmann out of Inconel 718 and welded together. Inconel is a super alloy which can take temperatures up to 1,800 deg. F.
The working layout from which the center section was built is the 2nd drawing down. The cruise missile used a solid booster for take off. Once on its way, the engine operated as a ram jet. The air inlet is shown on the front. The advanced version designed by Hollmann was the Delta configured tank which would provide more lift during flight from its tank section and hold more fuel. See drawing below. Once the missile was ejected from the B-1 weapon’s bay, the vans would open by using pyrotechnic squibes as shown by Hollmann on the last drawing.
 

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sferrin said:
Awesome! One of my all time favorite might-have-beens.
Mine as well make a nice high speed strike weapon that we could have had for decades
 
...
 

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Anti AWACS ? with or without a nuke ? and from what aircraft ?
I imagine that the Aircraft that can launch it list is far longer then those that cant since it was tested on a A-7.

So a F15 and F16 should more then able to launch this. And since it does have an active radar seeker as well it can be both honestly.
 
I think that the ASALM design should be dusted off, updated, tested and put into production.
 
@overscan (PaulMM) linked to a blog post on the ramjet of the SA-6 Gainful over on the Propulsion section of the forum, by a US engineer who was tasked reverse-engineering the engine from missiles cpatured during the Yom Kippur War.

The same engineer also worked on ASALM, and has another post on the missile in question.

 
The one that could only fit six was McD. The one that can fit eight was MM. You can see six on the rotary launcher with spots for two more.
 
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