US Army - Lockheed Martin Long Range Precision Fires (LRPF)

[Scott Kenny]

I was not aware there were any problems with air breathing hypersonics, though I agree the LRHW should be put into service. I do not think they will ever exist in sufficient number to be decisive, but they still represent a nearly unstoppable capability against very high value targets. The ARRW on the other hand does not seem to really fill a useful niche; it requires B-52s to carry a non useful number of them in lieu of other long range payloads. HACM is the real winning technology, longer run.

And "longer run" is the key statement there.

Do a run of a hundred or so ARRWs, assuming the stupid things will actually launch right. That's the "we have a hypersonic capability RIGHT NOW" answer, while we work the bugs out of HACM. Also, I believe that the B-21 bomb bay is long enough to carry ARRW sized weapons, but I think just 4 in 2+2 columns. 8 or even 4 is probably way too wide a load on a rotary launcher.

And same for LRHW, to have hypersonics deployed on ship until HACM is ready.

 

[bobbymike]

Army artillery needs more range, mobility and autonomy, study finds

The Army's conventional fires study is leading the service to focus on munitions range and capacity as well as more mobile and autonomous systems.

www.defensenews.com

 

[Josh_TN]

And "longer run" is the key statement there.

Do a run of a hundred or so ARRWs, assuming the stupid things will actually launch right. That's the "we have a hypersonic capability RIGHT NOW" answer, while we work the bugs out of HACM. Also, I believe that the B-21 bomb bay is long enough to carry ARRW sized weapons, but I think just 4 in 2+2 columns. 8 or even 4 is probably way too wide a load on a rotary launcher.

And same for LRHW, to have hypersonics deployed on ship until HACM is ready.

how often is a B-52 going to available to fire ARRW in theater? Would four of that missile be worth more than twenty JASSM? How many AGM-183s can be built in the next several years before HAVM enters production? I just do not see the value.

 

[Cordy]

In how often is a B-52 going to available to fire ARRW in theater? Would four of that missile be worth more than twenty JASSM? How many AGM-183s can be built in the next several years before HAVM enters production? I just do not see the value.

April 2017 US Navy launched 59 Tomahawk cruise missiles from the Mediterranean Sea into Syria, aimed at Shayrat Airbase and had zero impact so think a token 100 ARRWs launched against China, a much, much larger country than Syria the outcome would be any different.

 

[Scott Kenny]

how often is a B-52 going to available to fire ARRW in theater? Would four of that missile be worth more than twenty JASSM? How many AGM-183s can be built in the next several years before HAVM enters production? I just do not see the value.

8x per BUFF, I think, plus whatever is in the bomb bay (volume wise, another 4x, I think). 4 ARRW under each wing and 4 in the belly is what I'm leaning towards, and is almost 80,000lbs.

So you make about 240 missiles in one year, and another 240 the next year. That's enough to arm 40 BUFFS with 12x ARRW each.

 

[Josh_TN]

8x per BUFF, I think, plus whatever is in the bomb bay (volume wise, another 4x, I think). 4 ARRW under each wing and 4 in the belly is what I'm leaning towards, and is almost 80,000lbs.

So you make about 240 missiles in one year, and another 240 the next year. That's enough to arm 40 BUFFS with 12x ARRW each.

The current rack seems to only accept two per external station. Internal carriage and launch probably would require more testing to confirm separation characteristics, assuming the rotary launcher can accommodate the weapon without modification. 4 seems like the practical limitation for the next year or two even if they were purchased. Also I think some kind of adapter is needed for the standard heavy store station.

The new JSM line is producing all of ~50 missiles a year; there is no way that more than a couple dozen ARRW are going to be able to be produced a year, especially if the program is a dead end at a hundred or two. It is just a niche technology that turned out not to have much real world use: it is a light payload likely with no terminal guidance that costs tens of millions of dollars which can only be carried in fleetingly small numbers on one type of strategic bomber. I can understand why the USAF pulled the plug. In fact I think the reason test results have not been forthcoming is not to cover up failures but rather to cover up success: they don’t want to be forced to buy a missile that just does not fill a useful operational need.

 

[Kat Tsun]

Considering that we can get working BGVs right now and air-breathing hypersonics don't seem to be working so well, I'd rather get a small number of BGVs as the temporary solution till the air breathers are working.

Problem being that the scramjet airbreathers are more reliable than air-launched boost-glide weapons right now. Yeah it's weird.

 

[Josh_TN]

Problem being that the scramjet airbreathers are more reliable than air-launched boost-glide weapons right now. Yeah it's weird.

Well they are certainly dramatically more efficient, less expensive, and lighter weight. Boost glide weapons require a huge amount of energy that is rapidly bled off due to the log relationship of speed and drag: you have to boost to incredibly high speeds (and likely high minimum ranges) to get your glider to have an average travel speed far lower than the burnout speed. And you need an object that can survive that peak speed even though it technically might not even be hypersonic when it arrives over the target. Where as a pure scramjet boosts to a minimum effective speed and altitude to be then accelerates to its cruise speed, which is also its maximum speed. It does not need to survive harsher thermal stress than its cruise speed. X-51 was just aluminum and titanium, with a little bit of space shuttle tile material on the nose. The whole stack was like 4000lbs, using old technology milling for the engine, a flow through four foot long interstage, and an off shelf ATACMS engine. A massed produced HACM need not be much more expensive than an SM-6 or LRASM and is probably only a 3000 lb class weapon. F-15 is the threshold carrier.

EDIT: and the slower peak speed of a scramjet means that using a terminal sensor is probably not that problematic; it would not be operating in a flight regime dramatically different than an BVR AAM launched by a fighter moving supersonic. You might have to be a little creative with radome placement, but an AESA seeker would allow for dorsal or ventral positioning, with ventral being a lot more practical for a high flying weapon.

 

[Scott Kenny]

Problem being that the scramjet airbreathers are more reliable than air-launched boost-glide weapons right now. Yeah it's weird.

Very.

 

[Firefinder]

Problem being that the scramjet airbreathers are more reliable than air-launched boost-glide weapons right now. Yeah it's weird.

Not really if you stop to think bout it.

We been messing around with Ram/Scramjets types since what the 50s? With multiple different designs that just missed making it prime time due to multiple reasons ranging from do we need this to budget. We have loads of experience with thise that we can just look over at the old file cabinet and pull out a design to dust off. Like hell isn't HAWC basically the unholy hybrid of the ASLAM and X43?

While the boost gliders always been a fairly niche deal due to their inherent limitations. That one always been a cool trick to mess around with and rarely a serious weapon idea til recently. Even the old Pershing and Starbolt was more of a MARV then a hypersonic.

 

[Josh_TN]

Very.

Why? Air breathing hypersonics do not have to operate at anything like the speed and heat extremes of a boost glider. I think the hardest part of the engineering is keeping the vehicle stable and keeping the flame lit. But HAWC seems to have already achieved that with two different contractors.

 

[Scott Kenny]

Why? Air breathing hypersonics do not have to operate at anything like the speed and heat extremes of a boost glider. I think the hardest part of the engineering is keeping the vehicle stable and keeping the flame lit. But HAWC seems to have already achieved that with two different contractors.

Because the air breather needs to produce continuous thrust at Mach 8, while a Boost Glider gets punted up to Mach 10 ish and then glides.

 

[Josh_TN]

Because the air breather needs to produce continuous thrust at Mach 8, while a Boost Glider gets punted up to Mach 10 ish and then glides.

They seemed to have solved that problem. 3D printing inconel seems to have allowed for easy production of the complex flame holder geometry of the combustion chamber.

 

[Scott Kenny]

They seemed to have solved that problem. 3D printing inconel seems to have allowed for easy production of the complex flame holder geometry of the combustion chamber.

Definitely makes it easier to try new shapes. But Inconel is an (expletives deleted) to work with in general.

 

[Josh_TN]

Definitely makes it easier to try new shapes. But Inconel is an (expletives deleted) to work with in general.

They can apparently print the entire combustion chamber as a single piece now, so hopefully little additional work is required.

 

[Kat Tsun]

Not really if you stop to think bout it.

We been messing around with Ram/Scramjets types since what the 50s?

Reliable, proven hypergliders existed decades before reliable, proven scramjets first burned. The TPS on C-HGB functions fine.

The "weird" part is that the same company that had fairly little trouble adapting Tomahawk to ground launch, developing a ground launched boost-glide missile, and are making the Zumwalts into hypersonic missile cruisers somehow can't make a B-52 drop a rocket reliably.

ARRW's problems all stemmed from relatively more simple things like shroud separation, shackle release failure, and booster ignition issues.

 

[Scott Kenny]

Reliable, proven hypergliders existed decades before reliable, proven scramjets first burned.

Didn't the US test a HGV off an Atlas in the early 1960s? or was that just a paper project?

The "weird" part is that the same company that had fairly little trouble adapting Tomahawk to ground launch, developing a ground launched boost-glide missile, and are making the Zumwalts into hypersonic missile cruisers somehow can't make a B-52 drop a rocket reliably.

ARRW's problems all stemmed from relatively more simple things like shroud separation, shackle release failure, and booster ignition issues.

Yeah, that's what I don't get. At all.

 

[Kat Tsun]

Didn't the US test a HGV off an Atlas in the early 1960s? or was that just a paper project?

X-23 PRIME was testing thermal protection I think. I was specifically thinking of the Avangard and the Prompt Global Strike hypergliders.

Yeah, that's what I don't get. At all.

It could be as simple as an inexperienced team of fresh engineers grouped with a slightly out of practice oldster who forgot some stuff about the B-52 since he last worked on it. D.K. Brown talks about how the Castle-class OPVs were done as a training exercise to build up to a new ASW warship, but were still produced as a weapon system. He talks about it a bit and mentions him, having been "18 years out of practice", was still the most experienced member on the team.

That's the most charitable explanation.

LRHW didn't run into these issues. Neither did SMRF/Typhon. CPS likely won't either, but it may run into issues with the Zumwalt itself, who knows. Lockheed is doing/has done all three of these.

FWIW once ARRW finally solved the release, booster ignition, shroud separation, and hyperglider release problems, the actual hyperglider worked fine, too. It's just that ARRW's early failures tanked the program. MTA is pretty strict, because it's explicitly meant to bring prototypes to production, and well designed prototypes have few failures.

 

[GeorgeA]

Didn't the US test a HGV off an Atlas in the early 1960s? or was that just a paper project?

Yes, the McDonnell Model 122E BGRV. Four flight attempts in 1967-68 using Atlas launchers from VAFB. Two were considered successes. 4000 mi range, 2000 mi crossrange.

 

[Firefinder]

Reliable, proven hypergliders existed decades before reliable, proven scramjets first burned. The TPS on C-HGB functions fine.

The "weird" part is that the same company that had fairly little trouble adapting Tomahawk to ground launch, developing a ground launched boost-glide missile, and are making the Zumwalts into hypersonic missile cruisers somehow can't make a B-52 drop a rocket reliably.

ARRW's problems all stemmed from relatively more simple things like shroud separation, shackle release failure, and booster ignition issues.

There no weirdness in making a Tomahawk Ground launchable. Thats an literally an original feature of the system with the Air Force version the BGM109 Gryphon, through everyone called it the Tomahawk Inservice apparently. The difference between launching from Sea and land is basically nil. Like so long as you avoid exceeding the generous viberation loading the Tomahawk will not care if its a Burke VLS or a Truck VLS its sitting in. And considering they basically took the MK41 cell holding structure and blast deflector and welded it to a hydro jack to lift it verticle for launching? Whats the weirdness, fucking that up be weird cause it so easy since we know all the parts work. Apperantly it was largely Raytheon making the thing work.

The Zumwalts are not being modded by Lockmart. Its being all done by Ingalls Shipbuilding. Which has nothing to do with Lockheed. They are basically under Northrop Grumman, completely different company. Only thing Lockmart doing is supplying the missile and making sure the coding plays nice. Everything else is on Hill.

While the LRHW has been having its own issues since it has yet have an all up test from its fielding launcher that the Army going to USE. Its been suffering numerous issues with said launcher that result in the main test last September being Cancel. Nor has the complete stack flew together yet which may make issues for the Navy since they are using the same missile for the Zumwalts. That Programs is having similar issues with getting the thing to launch.

So no Weirdness there.

Lockmart just been having issue getting their new shit to fly.

 

[Scott Kenny]

Yes, the McDonnell Model 122E BGRV. Four flight attempts in 1967-68 using Atlas launchers from VAFB. Two were considered successes. 4000 mi range, 2000 mi crossrange.

Okay, didn't have the timeline quite right. Thanks!

 

[Kat Tsun]

Lockmart just been having issue getting their new shit to fly.

...exactly.

All failures of ARRW were related to the missile, designed by Lockheed. Literally nothing else.

The B-52s did not have pylons break off and drop ARRWs into the sea, the thermal protection system of the hyperglider did not fail on reentry except when it was carried into atmosphere by the booster itself, the kinetic warhead and guidance systems functioned properly when the booster deigned to detach and fall back to Earth.

A rocket that goes fast and drops a warhead that hits something with a metal rod is not hard to make. We've been doing it for decades with ICBMs like Minuteman, IRBMs like Pershing, and to a lesser extent with GMLRS and Alternative Warhead. There is nothing here unknown or novel, or at least that shouldn't be, assuming the engineers are competent. The novelty was the payload of the rocket the engineers were making, which was a known quantity, because it has been in a state of development for almost 20 years now beginning with the FALCON.

A cruise missile that breathes at supersonic speeds, and travels through atmosphere while maneuvering at high supersonics is hard to make, or at least it used to be. This seems to no longer be the case given how successful X-43, X-51, and HAWC were in general, but it's very much a novel piece of equipment compared to even FALCON. The only real novelty of FALCON and its progeny was trying to get the TPS to go from "exotic superalloys" to "carbon" for the duration of a atmospheric glide.

It can only really be explained by a lack of experience with either missile design in general, since the missile kept failing, or something to do with the B-52 integration since a lot of early problems were related to things like release from pylons. I suspect the former was the predominant issue, because of the test that failed due to improper shroud deployment and subsequent failure to release the BGV on 13 MAR 24, though.

The good news is that by the end of it all the Lockheed team had managed to gain sufficient competence to actually fire a complete prototype unit, one remnisicent of a operational weapon, and it succeeded on the first try. The bad news is that they were too incompetent to meet the initial fielding timeline and ran out of alloted budget and hours for further testing. For all anyone knows, at least for now, ARRW may still be an unreliable hunk of junk that just got a lucky last shot in.

 

[Josh_TN]

I think ARRW was always doomed as a concept, once HAWC was successful. I think the USAF was pleasantly surprised by how achievable scramjet technology was after that, and buying a super expensive niche strategic bomber system as a temporary measure was never going to fly. That is not to say the two systems are equivalent - ARRW had longer ranges and higher speeds. But by being deployed on tactical aircraft, being far cheaper to produce, and potentially having a terminal seeker, HACM became a much more attractive development path once HAWC proved the concept. I suspect the 3D printing technology (and likely very exquisite computer modeling for design) used in both demonstration items was the breakthrough that caused scramjet to jump in front of boost glide. Of course for the next several years there is still an unfulfilled gap, but ARRW likely could not be fielded in enough numbers to be relevant.

 

[Forest Green]

I think ARRW was always doomed as a concept, once HAWC was successful. I think the USAF was pleasantly surprised by how achievable scramjet technology was after that, and buying a super expensive niche strategic bomber system as a temporary measure was never going to fly. That is not to say the two systems are equivalent - ARRW had longer ranges and higher speeds. But by being deployed on tactical aircraft, being far cheaper to produce, and potentially having a terminal seeker, HACM became a much more attractive development path once HAWC proved the concept. I suspect the 3D printing technology (and likely very exquisite computer modeling for design) used in both demonstration items was the breakthrough that caused scramjet to jump in front of boost glide. Of course for the next several years there is still an unfulfilled gap, but ARRW likely could not be fielded in enough numbers to be relevant.

They could have launched ARRW off F-15EX centreline pylons too probably though? There are other theories about the cancellation of the project, in that missile itself was too expensive for an expendable system and instead they will drop the same RV out of a hypersonic aircraft, which will then RTB.

 

[Kat Tsun]

I think ARRW was always doomed as a concept, once HAWC was successful. I think the USAF was pleasantly surprised by how achievable scramjet technology was after that, and buying a super expensive niche strategic bomber system as a temporary measure was never going to fly. That is not to say the two systems are equivalent - ARRW had longer ranges and higher speeds. But by being deployed on tactical aircraft, being far cheaper to produce, and potentially having a terminal seeker, HACM became a much more attractive development path once HAWC proved the concept. I suspect the 3D printing technology (and likely very exquisite computer modeling for design) used in both demonstration items was the breakthrough that caused scramjet to jump in front of boost glide. Of course for the next several years there is still an unfulfilled gap, but ARRW likely could not be fielded in enough numbers to be relevant.

I'm still under the impression that ARRW was meant to be a stopgap to give Air Force a hypersonics delivery capability for the joint fight. Nothing more, nothing less, just something Air Force generals could tack on a box in the bureaucratic fights that joint planning involves. Less of a necessary capability and more of a "me too" following in the footsteps of the Army and Navy. HACM was always the intended full monty.

The USN might need both for its warships and aircraft, but planes are fast, so the need for ARRW's long range is dubious for the USAF.

ARRW may go unfilled forever and I doubt its absence would be felt by the joint force. LRSO seems far more important for the B-52s than a kinetic energy TEL buster tbh. OTOH HACM seems flexible enough that it provides a useful utility, and is less a Air Force thing and more a joint Air Force-Navy thing, to give the carriers some relevance in that regard.

 

[Josh_TN]

I suspect HACM will have a terminal sensor, probably AESA radar based. And if that is the case, then it can likely be used against ships and multi engined aircraft, on top of land attack. In which case it will be an almost unstoppable weapon against most any high value target. If so, you can see why ARRW just is not the money.

 

[Scott Kenny]

I suspect HACM will have a terminal sensor, probably AESA radar based. And if that is the case, then it can likely be used against ships and multi engined aircraft, on top of land attack. In which case it will be an almost unstoppable weapon against most any high value target. If so, you can see why ARRW just is not the money.

I cannot imagine a modern missile without terminal guidance.

 

[Kat Tsun]

I suspect HACM will have a terminal sensor, probably AESA radar based. And if that is the case, then it can likely be used against ships and multi engined aircraft, on top of land attack. In which case it will be an almost unstoppable weapon against most any high value target. If so, you can see why ARRW just is not the money.

Pretty sure ARRW's hyperglider had terminal guidance too. Both TBG and C-HGB do the same thing: hit moving targets before they duck into a culvert or protective bunker, destroy SAM sites and headquarters command posts, and attack warships. TBG is just derived from DARPA's HTV-2, while C-HGB is derived from Sandia's SWERVE, and that's about the only difference AIUI.

I cannot imagine a modern missile without terminal guidance.

GMLRS comes to mind. Ditto TLAM-Ds which are still kicking around.

I guess it depends on if you define "modern" as "in combat use today" or "entering combat service maybe today, maybe tomorrow".

 

[Josh_TN]

I cannot imagine a modern missile without terminal guidance.

I suspect ARRW did not have one, given the speed envelope. I think that was part of the problem.

 

[Josh_TN]

Pretty sure ARRW's hyperglider had terminal guidance too. Both TBG and C-HGB do the same thing: hit moving targets before they duck into a culvert or protective bunker, destroy SAM sites and headquarters command posts, and attack warships. TBG is just derived from DARPA's HTV-2, while C-HGB is derived from Sandia's SWERVE, and that's about the only difference AIUI.



GMLRS comes to mind. Ditto TLAM-Ds which are still kicking around.

I guess it depends on if you define "modern" as "in combat use today" or "entering combat service maybe today, maybe tomorrow".

I have a hard time believing a glider boosted to those speeds had a terminal sensor, or at least one that worked reliably. Certainly a cruise missile that operates at Mach 5-6 would be a lot easier to accomplish.

 

[Scott Kenny]

I have a hard time believing a glider boosted to those speeds had a terminal sensor, or at least one that worked reliably. Certainly a cruise missile that operates at Mach 5-6 would be a lot easier to accomplish.

It's a glider. It slows down as it travels.

Significantly simpler than terminal guidance for an air-breather at Mach 9.

Crud, ballistic missile RVs end up dropping below about Mach 3 at 30kft, IIRC, due to the increased atmospheric drag.

 

[Josh_TN]

It's a glider. It slows down as it travels.

Significantly simpler than terminal guidance for an air-breather at Mach 9.

Crud, ballistic missile RVs end up dropping below about Mach 3 at 30kft, IIRC, due to the increased atmospheric drag.

Perhaps, but operating at Mach 5 is a pretty easy ask compared to anything faster.

 

[bobbymike]

Okay, didn't have the timeline quite right. Thanks!

This might be of interest

Lightning Bolts: First Maneuvering Reentry Vehicles
Book by William Yengst

 

[Kat Tsun]

I have a hard time believing a glider boosted to those speeds had a terminal sensor, or at least one that worked reliably. Certainly a cruise missile that operates at Mach 5-6 would be a lot easier to accomplish.

If TBG does have a terminal sensor, I'd imagine it's a radar, but more like the Pershing II's RV than a Hellfire. Granted this is an assumption based on the part that most U.S. hypergliders were designed under the expectation of attacking a mobile target, like an artillery piece or TEL. The exception is SWERVE which was for nuclear delivery and is contemporary with the Soviet Avangard.

A large area kinetic attack, like the GMLRS Alternative Warhead, would be able to achieve lethality against a TEL, SAM site, headquarters, or a artillery battery without a terminal seeker I guess.

Perhaps, but operating at Mach 5 is a pretty easy ask compared to anything faster.

This is ultimately why HTV-2 turned into ARRW's TBG-derived M5-7 glider, to be fair. HTV-2 kept disintegrating during its flight tests. ):

 

[Forest Green]

Should the U.S. Navy Adopt Precision Strike Missiles for the Mark 41 VLS? - Naval News

Naval News asked naval military analysts what are their thoughts on if the U.S. Navy should adopt the U.S Army’s Precision Strike Missile aboard their AEGIS warships equipped with the Mark 41 VLS.

www.navalnews.com

 

[NMaude]

Does anyone know how many LRIP phase PrSMs have been built So far?

 

[Forest Green]

Does anyone know how many LRIP phase PrSMs have been built So far?

An amount (unspecified) was procured for $219m in 2023. In 2022 there was a $77m order too.

https://twitter.com/x/status/1768241880196694287

View: https://x.com/AirPowerNEW1/status/1768241880196694287?s=20

 

[NMaude]

Given the events of the last two years in Ukraine I wonder if the US Army is trying accelerate production of the PrSM?

 

[Scott Kenny]

Given the events of the last two years in Ukraine I wonder if the US Army is trying accelerate production of the PrSM?

Be surprised if they weren't!

I mean, you get new missiles in hand replacing ATACMs, you can also "donate" the old stockpiled reloads of those ATACMs to Ukraine.

 

[NMaude]

you can also "donate" the old stockpiled reloads of those ATACMs to Ukraine.

Which also saves the US DOD money as they don't have to de-mil them after their retirement.