ASALM (Advanced Strategic Air-Launched Missile)

[Forest Green]

I'm thinking that Mach 3 at ground level may actually be more useful than Mach 8-10 at 20+km.

 

[zjz]

With all of the renewed focus in the past five years or so on high supersonic and low hypersonic weapons I wonder if someone will dust off the ASALM programme and then restart it but taking into account all the advances in the relevant areas of aerodynamic research, material sciences, manufacturing technology, avionics and programming?

It would have been LRASM-B, but the program was dropped in favor of putting all effort on LRASM-A aka JASSM-based AShM .....

 

[zjz]

I'm thinking that Mach 3 at ground level may actually be more useful than Mach 8-10 at 20+km.

If you look at systems capable of sea-skim (Russian AShM), max Mach is around 2.5+ at sea level .... this probably marks the material (aluminium alloy, steel) limits to aerodynamic heating ....

Of course you can argue the use of composites, but that would probably make it expensive to be considered for one-shot devices .....

 

[NMaude]

Of course you can argue the use of composites, but that would probably make it expensive to be considered for one-shot devices ...

Or a titanium-alloy airframe for low-level M3 cruise.

 

[Forest Green]

If you look at systems capable of sea-skim (Russian AShM), max Mach is around 2.5+ at sea level .... this probably marks the material (aluminium alloy, steel) limits to aerodynamic heating ....

Of course you can argue the use of composites, but that would probably make it expensive to be considered for one-shot devices .....

What's the limit of the same material at 20km altitude? Can it do Mach 10? Probably not. So it's likely to be composites either way.

 

[NMaude]

What's the limit of the same material at 20km altitude? Can it do Mach 10? Probably not. So it's likely to be composites either way.

There are titanium-alloys too.

 

[Joaquin]

ASALM chapter from Nuclear Weapons Databook, Volume I

Hey I have that book!

This site is amazing.

 

[sferrin]

If you look at systems capable of sea-skim (Russian AShM), max Mach is around 2.5+ at sea level .... this probably marks the material (aluminium alloy, steel) limits to aerodynamic heating ....

Of course you can argue the use of composites, but that would probably make it expensive to be considered for one-shot devices .....

SLAM was intended to fly at Mach 3+ on the deck. It had gold-plated inconel skin.

 

[Scott Kenny]

SLAM was intended to fly at Mach 3+ on the deck. It had gold-plated inconel skin.

And was designed in a price-no-object time period as an unmanned bomber more than a missile. (multiple warheads, all being dropped in different locations)

Gotta admit, I do kinda like Charles Stross' idea for why SLAM was made: as an attempt to deal with shoggoths.

 

[harpoonjoe]

enjoy

I believe I have the original artwork for this. Do you know anymore about it?

 

[flateric]

Rockwell International ASALM entry

 

[harpoonjoe]

My grandfather was director of engineering for McDonnell Aircraft and later worked on the ASALM project. I was given this artwork (which proudly hangs in my office) after his passing, which I believe to be the original.

 

[flateric]

Martin Marietta ASALM team logo

 

[Dew]

Some bits & pieces:


from Unfolding the air vanes on a supersonic air-launched missile


Propulsion Technology Validation program belt buckle on eBay

 

[iwantmoresources]

Would the ASALM have fit into a VLS as found on the Ticonderoga/Arleigh Burke or into an Armoured Box Launcher? It seems to be a strong contender for the supersonic low altitude AShCM niche.

 

[zjz]

Would the ASALM have fit into a VLS as found on the Ticonderoga/Arleigh Burke or into an Armoured Box Launcher? It seems to be a strong contender for the supersonic low altitude AShCM niche.

See post #1

https://www.secretprojects.co.uk/threads/asalm-advanced-strategic-air-launched-missile.466/#post-3224

 

[Dew]

ASALM flight sequence

Similar from TELEMETRY FOR ASALM-PTV MISSILE

 

[iwantmoresources]

Looking at this concept, it seems that this was the ideal Triservice medium range cruise missile. Compatible with rotary launchers, VLS, ABLs, high cruise speed and thus low reaction time, and if fitted with a conventional warhead, its impact speed probably would be able to compensate for the lack of boom. PLUS the fact that it could be used as an LACM, AShCM, AAM and SAM with very little changes.

 

[sferrin]

Looking at this concept, it seems that this was the ideal Triservice medium range cruise missile. Compatible with rotary launchers, VLS, ABLs, high cruise speed and thus low reaction time, and if fitted with a conventional warhead, its impact speed probably would be able to compensate for the lack of boom. PLUS the fact that it could be used as an LACM, AShCM, AAM and SAM with very little changes.

And test articles flew well above Mach 5. With a ramjet.

 

[iwantmoresources]

And test articles flew well above Mach 5. With a ramjet.

Would that not cause structural issues though?

In any case, i wonder what the Triservice designation would have been. I’m going to guess and say AGM-115, with the speculative variants being BGM/RGM/AIM/RIM-115.

This neat “little” missile could also be a great Foxbat/Foxhound chaser- 300 nm range, an average speed of Mach 4.5 = very easy Foxhound kill.

 

[iwantmoresources]

Would that not cause structural issues though?

In any case, i wonder what the Triservice designation would have been. I’m going to guess and say AGM-115, with the speculative variants being BGM/RGM/AIM/RIM-115.

This neat “little” missile could also be a great Foxbat/Foxhound chaser- 300 nm range, an average speed of Mach 4.5 = very easy Foxhound kill.

Although with the AIM-115i am not sure what would be able to carry it fully fueled on a single pylon.

 

[sferrin]

Would that not cause structural issues though?

Why?

 

[apparition13]

Why?

It wasn't designed to. The missile just kept accelerating. You posted the story in this thread back in 2015. It was designed to fly at Mach 4, but a fuel control problem sent it to Mach 6. Too much speed might cause structural failure due to excessive heating and/or pressure, and too much fuel burn might reduce range.

 

[Dew]

And test articles flew well above Mach 5. With a ramjet.

..at low level!

I love the following section from GW Johnson's blog post :

The final telemetry from the vehicle just before we lost it, translated as "I am at Mach 6 and still accelerating as my skin begins to melt. I just ran out of fuel. Goodbye."

 

[Firefinder]

Although with the AIM-115i am not sure what would be able to carry it fully fueled on a single pylon.

That was literally how the Tesr articles were fired.

Right off of a A7 hardpoint.

Most US tac craft hardpoints are rated for 3000 to 4000 pounds. The ASALM was around 1800 fully kitted out.

 

[Forest Green]

..at low level!

I love the following section from GW Johnson's blog post :

Not this?

The final telemetry from the vehicle just before we lost it, translated as "I am at Mach 6 and still accelerating as my skin begins to melt. Owww! It burns... it burns...."

 

[Dew]

Charlie French, Aeronautical Engineer
Charlie French worked 36 years for Martin Marietta (now Lockheed Martin) and served on the following projects before retiring in 1985.

ABOVE: Congratulations after another successful and last ASALM-PTV flight. Martin Marietta built 7 test missiles and flew all 7 successfully. From left to right: Frank Webster from Systems Dept., “Charlie” French from Aerodynamics, Jim Bucy from Propulsion, and Marty Koshar who was Project Manager.

ABOVE: SLAT: Supersonic Low Altitude Target. Pictured here are (left to right) Charlie French (Areodynamics), Mendel Mullinax (Model Mechanic) and Lawrence Gilbert (Aerodynamics.)

 

[NMaude]

It perturbs me how neither the ASALM nor the SLAT entered production, the ASALM would no doubt had the Soviets shitting bricks if it had entered service.

 

[TomS]

It perturbs how neither the ASALM nor the SLAT entered production, the ASALM would no doubt had the Soviets shitting bricks if it had entered service.

Well, if SLAT had actually worked, I'm pretty sure it would have gone to production. But it went 1-for-7 in flight testing, which is a very bad sign. Makes me suspect that ASALM probably wasn't as much of a sure thing as everyone seems to think.

 

[Moose]

Looking at this concept, it seems that this was the ideal Triservice medium range cruise missile. Compatible with rotary launchers, VLS, ABLs, high cruise speed and thus low reaction time, and if fitted with a conventional warhead, its impact speed probably would be able to compensate for the lack of boom. PLUS the fact that it could be used as an LACM, AShCM, AAM and SAM with very little changes.

By the time this was in testing, Navy had no interest in liquid fuel missiles on ships.

 

[NMaude]

Navy had no interest in liquid fuel missiles on ships.

Really? Then explain the presence of R/UGM-84 Harpoons and R/UGM-109 Tomahawk cruise-missiles on USN warships? Both use jet-fuel not solid-propellant.

 

[sferrin]

Well, if SLAT had actually worked, I'm pretty sure it would have gone to production. But it went 1-for-7 in flight testing, which is a very bad sign. Makes me suspect that ASALM probably wasn't as much of a sure thing as everyone seems to think.

Wonder why they picked it for LRASM-B? (And then cancelled it almost before the ink was dry.)

 

[sferrin]

By the time this was in testing, Navy had no interest in liquid fuel missiles on ships.

Harpoon, Tomahawk. . .

 

[TomS]

Wonder why they picked it for LRASM-B? (And then cancelled it almost before the ink was dry.)

Because the other proposals were worse? Just a guess.

 

[TomS]

Really? Then explain the presence of R/UGM-84 Harpoons and R/UGM-109 Tomahawk cruise-missiles on USN warships? Both use jet-fuel not solid-propellant.

Kerosene is easy. ASALM used a much trickier high-density fuel called Shelldyne-H. It was hard to ignite when cold, and apparently tended to congeal on the sides of the fuel tanks rather than flowing into the engine. Probably not insurmountable problems, but definitely complications.

 

[sferrin]

Well, if SLAT had actually worked, I'm pretty sure it would have gone to production. But it went 1-for-7 in flight testing, which is a very bad sign. Makes me suspect that ASALM probably wasn't as much of a sure thing as everyone seems to think.

Depends on why it failed. As we've seen in many hypersonic launch attempts it's possible to fail many times and not even get a chance to test the flight vehicle. ASALM (the PTV anyway) was apparently very successful.

"ASALM-PTV flew 7 times in flight tests at Eglin AFB in the 1979-1980 time frame. The first test experienced a throttle runaway incident, and so it unintentionally set a hypersonic speed record for vehicles powered by airbreathing propulsion, and furthermore it did that at low altitude! That speed record stood for nearly a quarter century, until NASA broke it with its X-43A scramjet test article in 2004, at very high altitude with a brief 3-second airbreathing burn, rocket-boosted all the way to test speed at Mach 7.

ASALM-PTV accidentally reached about Mach 6 in that runaway ramjet burn, starting from a Mach 2.5 ramjet takeover at end of rocket boost, after a 20,000 foot launch for that first test. The original intent for the first test was for the vehicle to fly a racetrack pattern, at 20,000 feet and a sedate Mach 2.5, to fuel exhaustion, using simple timed turns, in order to check out the ramjet systems. Because of the throttle runaway problem, it left the range and reached fuel exhaustion at hypersonic speed, before the first timed turn could occur.

We found it 3-4 days later, stuck like a big steel dart, in a farmer's field, about 10 miles outside the airbase. The final telemetry from the vehicle just before we lost it, translated as "I am at Mach 6 and still accelerating as my skin begins to melt. I just ran out of fuel. Goodbye." Well, at least the other ramjet systems besides the throttle control worked just fine, obviously. So we counted that one as "half-successful".

The other 6 ASALM-PTV flight tests were letter-perfect, including the design cruise missile mission: subsonic air launch, supersonic climb to cruise altitude (80,000 feet), high supersonic cruise (Mach 4) for a long range, and high-supersonic dive (terminal about Mach 5) onto its target. With the first one "half-successful", that made us 6.5 for 7. Not too bad!"

An Ex Rocket Man's Take On It

The ravings of a trained mind.

exrocketman.blogspot.com

 

[NMaude]

ASALM used a much trickier high-density fuel called Shelldyne-H. It was hard to ignite when cold, and apparently tended to congeal on the sides of the fuel tanks rather than flowing into the engine.

Wouldn't friction heating of the skin make the fuel more liquid and easier to pump into the combustion chamber?

 

[Hanz2k]

Wouldn't friction heating of the skin make the fuel more liquid and easier to pump into the combustion chamber?

I assume later in the flight it helps. But you need the same fuel to get to this moment

 

[NMaude]

But you need the same fuel to get to this moment

Don't forget that it had a solid-propellant boost-phase so aerodynamic friction would've heated up the fuel nicely.

 

[Scott Kenny]

By the time this was in testing, Navy had no interest in liquid fuel missiles on ships.

No, the Navy has no interest in exotic/dangerous liquid fuels like hydrazine on ships.

Standard kerosene is not particularly dangerous, and is used for ship fuel anyways.