Post - B-21 long range strike capability

EmoBirb said:
Wasn't there also an LAP study/proposal? Basically high speed, low altitude flight, similar to what the B-1B was supposed to do?

Edit: found it, although I could have been sure I read somewhere that it was supposed to be supersonic
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Some more information on the low altitude penetrator. Acoustic detection seems much more feasible under current technological capabilities (the Ukrainians already used it to detect Shahed-136 drones).
 
Just pondering on the possibility of IR lamps and curing the skin on the wing itself but completely forgot the proessure side of the process.

I am in the end of life process with my cat tonight so possibly a bit distracted.

Sorry folks.
 
Scott Kenny said:
Probably better, but that would require a new design program starting now. More or less.
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B-52 is currently planned to stay on till early to mid 2050s. A 10 year EMD and 15-20 year overall program for a 'second bomber / long range strike aircraft' is a reasonable assumption. That means that a future LRS aircraft would need to enter EMD around the late 2030s after 5-10 years of technology development. Depending on what sort of long range planning and analysis of alternatives is done for the 2050-2100 long range strike portfolio we could be looking at a very different set of attributes than a long range payload truck (B-52). I would not rule out long range hypersonic strike as a potential source of investment for a 2050+ fielding timeframe.

View: https://youtu.be/GTIB4uWxpnI?t=250
 
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Foo Fighter said:
Just pondering on the possibility of IR lamps and curing the skin on the wing itself but completely forgot the proessure side of the process.

I am in the end of life process with my cat tonight so possibly a bit distracted.

Sorry folks.
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I'm sorry to hear that, boss.

*hugs for you, skritches for the cat*
 
Josh_TN said:
It is probably too early to plan for the next bomber. USAF is already hinting that B-21 might have a limited life span.
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In fairness though, if that's the case, it's in large part due to the B-21 being rather vulnerable as a large, not so agile, subsonic aircraft. So if it's primary defense mechanism is being degraded in two or three decades, it will be less survivable. But even then I could see the B-21 sticking around for a long time, just focusing even further on stand off munitions. I'd be surprised if the B-21 serves less than 40 years.
 
The ability to field, reconstitute and replace/replenish a multidozen network of X-37B-like spacecraft capable of achieving good coverage wrt deploying space based but earth bound munitions despite odd and changing orbital dynamics is to me a deterrent game changer, and the functional long term / aspirational goal of both China and the US.

Short of that, very hypersonic uncrewed aircraft capable of repeatedly pummeling something with relatively cheap ordnance, despite some vague sense youre about to knock on their door repeatedly, is the intermediate goal.

The short term goal is Raider. The ability to deliver B-2 or better LO explosive effect delivery via a more networked or distributed approach. People can’t focus on what 20 B-2s are doing with the same kind of operational predictabilliry vs those 20 B-2s plus150-200 Raiders deploying every which way, all the time. Oh BTW it’s worth reminding ourselves of what a stupidly large lead the US has in strategic bomber design it currently enjoys. Best spam that.
 
EmoBirb said:
One:
https://twitter.com/x/status/1879759689296343500
View: https://x.com/FaySue6/status/1879759689296343500


Two:
https://www.sinodefenceforum.com/t/h-20-bomber-with-h-x-jh-xx.6451/post-1154683
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Either it could be the enlarged version of J-36 or the stretched flying wings with 6 x WS-15 turbofans. It emphasizes, long range, stealth, large payload, high supercruise, and high survivability.
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It's hard to believe that a bomber fitted with six low-bypass-ratio engines, carrying heavy payloads, and flying at high cruise speeds, could deliver long range.
 
JoshuaH said:
Right…then we can probably start weighing different options. JASSM-XR offers twice the range (1000nmi) but is 6m+ in length, I don’t know how expensive it will be compared with the current JASSM-ERs. Would it be better settling with a shorter standoff and a faster bomber or use larger missiles on a subsonic platform (using the extended standoff to guarantee safety). Compatibility with larger missiles also enables better capacity for potential hypersonic weapons. Doing supersonic dash is also really, really bad for signature management. Afterburners of Soviet bombers could be seen from orbit in the 1980s. Would the warning time to the opponent actually increase due to this discovered by space factor instead of decrease by speed…? Could extended supercruise be a better option since we might not want to engage the burners thousands of miles from the release point…? There’s probably a lot of maths to do here…
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Hic Rhodus, hic salta, see https://en.wikipedia.org/wiki/Hic_Rhodus,_hic_salta
 
Foo Fighter said:
Just pondering on the possibility of IR lamps and curing the skin on the wing itself but completely forgot the proessure side of the process.

I am in the end of life process with my cat tonight so possibly a bit distracted.

Sorry folks.
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As a fellow dedicated cat servant, my sincere well wishes and condolences.
 
EmoBirb said:
In fairness though, if that's the case, it's in large part due to the B-21 being rather vulnerable as a large, not so agile, subsonic aircraft. So if it's primary defense mechanism is being degraded in two or three decades, it will be less survivable. But even then I could see the B-21 sticking around for a long time, just focusing even further on stand off munitions. I'd be surprised if the B-21 serves less than 40 years.
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I fail to see how making a larger, more vulnerable aircraft is a viable alternative. People here are talking about a four engined supersonic monster; I cannot fathom how that would be a survivable option. If you are thinking that a bomber can outrun the threat, I think you are operating in the wrong century.
 
Josh_TN said:
I fail to see how making a larger, more vulnerable aircraft is a viable alternative. People here are talking about a four engined supersonic monster; I cannot fathom how that would be a survivable option. If you are thinking that a bomber can outrun the threat, I think you are operating in the wrong century.
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Blackbirds demonstrated that it's really hard to intercept a bomber at Mach 3+ and 80,000ft.

However, that comes with a side order of an IRCS the size of the rising sun. And going hypersonic makes that IRCS even worse.

It'd be an interesting discussion to see if you could do low-RCS Mach 2.2 at 70,000ft+. It'd still have issues with IRCS, but no aircraft has the ability to precisely track an IR signature at range.


The attached file shows the rather dramatic improvement in down and cross ranges you get from launching an AGM-69 SRAM at different heights and speeds.
Supercruise Pg 16.JPG
This came from Lockheed in parts of the Blackbird development. I believe that the comparisons are against a B-52 down on the deck and a B-58 at M1.6.
 
Scott Kenny said:
Blackbirds demonstrated that it's really hard to intercept a bomber at Mach 3+ and 80,000ft.

However, that comes with a side order of an IRCS the size of the rising sun. And going hypersonic makes that IRCS even worse.

It'd be an interesting discussion to see if you could do low-RCS Mach 2.2 at 70,000ft+. It'd still have issues with IRCS, but no aircraft has the ability to precisely track an IR signature at range.


The attached file shows the rather dramatic improvement in down and cross ranges you get from launching an AGM-69 SRAM at different heights and speeds.
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This came from Lockheed in parts of the Blackbird development. I believe that the comparisons are against a B-52 down on the deck and a B-58 at M1.6.
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Missiles also get much much faster nowadays though…
 
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JoshuaH said:
Right…then we can probably start weighing different options. JASSM-XR offers twice the range (1000nmi) but is 6m+ in length, I don’t know how expensive it will be compared with the current JASSM-ERs. Would it be better settling with a shorter standoff and a faster bomber or use larger missiles on a subsonic platform (using the extended standoff to guarantee safety). Compatibility with larger missiles also enables better capacity for potential hypersonic weapons. Doing supersonic dash is also really, really bad for signature management. Afterburners of Soviet bombers could be seen from orbit in the 1980s. Would the warning time to the opponent actually increase due to this discovered by space factor instead of decrease by speed…? Could extended supercruise be a better option since we might not want to engage the burners thousands of miles from the release point…? There’s probably a lot of maths to do here…
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IMO speed and bombload for survivability are most useful in the naval context? If you're part of a strategic air campaign then you'll have escort, so speed is useful but not crucial.

When it comes to slow walkers, I feel like modern engines could ameliorate that, be it through supercruise, improved fuel blends/engine design (Tu-22M/NK-25 burns very distinctly), or arcane signature management techniques.

In terms of the kind of fashion you're looking at, I was back of the napkin looking at like 30-60min of dash before launch, I can't remember the details but it indicated that non-barrier CAP, even with Su-27's range and speed, would struggle to intercept just on geometry. It's been a minute though.

I'm on mobile and can't figure out how to insert quotes while editing, but RE: SR-71 survivability, it was pretty solidly in the SA-5 engagement envelope, if memory serves. I should have some graphics on my laptop.

My thought regarding speed is that sprint speed is useful, but it's a trade off space and I'm not sure how signature management, speed, range and payload all interact. Given what we may see from F/A-XX and F-47, it might be eminently possible to meet a 1.5M sprint on a quite low observable platform with like ±15m of bays (configurable as 3x 4.5m or 2x 6m with some wiggle room? I'm spitballing

Finally, the concern about enemy missile range is the advent of quite advanced datalinks. I'll point out that BOMARC was doing like 500-700nmi (iirc) intercepts in 1961, so these kinds of stand off aren't exactly unprecedented.
 
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whatismoo said:
but RE: SR-71 survivability, it was pretty solidly in the SA-5 engagement envelope, if memory serves. I should have some graphics on my laptop.
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It needs to be kept in mind that in addition to its high-speed, high-altitude flight the SR-71 was also equipped with a comprehensive ECM suite.
 
whatismoo said:
I'm on mobile and can't figure out how to insert quotes while editing, but RE: SR-71 survivability, it was pretty solidly in the SA-5 engagement envelope, if memory serves. I should have some graphics on my laptop.
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With the speed and height the launch crews had to be perfectly positioned. The slightest turn and throttle change would put the Blackbird outside the engagement envelope by the time the missile arrived at 80,000ft.

IIRC it was Brian Shul who said that Blackbird SOP was to turn slightly and push the throttles up when the missile warning system reported a launch.
 
whatismoo said:
When it comes to slow walkers, I feel like modern engines could ameliorate that, be it through supercruise, improved fuel blends/engine design (Tu-22M/NK-25 burns very distinctly), or arcane signature management techniques.
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I have a rather pessimistic view towards high speed aircraft avoiding infrared satellite detection though... Infrared technology came a really long way since the DSP era: using staring array instead of scanning linear array alone improves detection SNR by hundreds of folds, because each pixel on the sensor exposes for about the time of the entire frame without needing to scan across it. The advent of LEO constellations would further improve the SNR by the square of the distance reduced, potentially giving thousands of folds in SNR improvement...
 
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whatismoo said:
In terms of the kind of fashion you're looking at, I was back of the napkin looking at like 30-60min of dash before launch, I can't remember the details but it indicated that non-barrier CAP, even with Su-27's range and speed, would struggle to intercept just on geometry. It's been a minute though.
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30-60min of dash at Mach 1.5 means only 750-1500km in dash range, it seems that improving missile range by that much (JASSM-ER to -XR) might be the easier option since the launcher only needs to drop the missile and go instead of start dashing. Also Su-27 might not be a representative threat for future interceptors... Setting J-36 as the representative threat, I would expect at least F-22 level of super cruise capability with tanker support for the reach, paired with 300-400km range missiles (PL-17).
 
whatismoo said:
Finally, the concern about enemy missile range is the advent of quite advanced datalinks. I'll point out that BOMARC was doing like 500-700nmi (iirc) intercepts in 1961, so these kinds of stand off aren't exactly unprecedented.
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The Earth's curvature limits the maximum line-of-sight detection range from a 40kft radar to a 40kft target to be ~700km. Any longer than that you probably have to base the sensor forward no matter how advanced the datalink is. Then the sensor becomes a huge target that can be disabled first. Of course the sensor can also be space-based, I guess war is going to be really different once both sides have all-seeing, real time targeting LEO constellations...
 
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I think you need an uncrewed striker that’s persistently fast, and has the range to slash into and exit the first island chain across a wide range of vectors.

Could this be done with current conventional technology? Probably, but the old LM statements from the SR-72 days suggest that getting to Mach 5 was doable, but really going hypersonic was a lot tougher. Does this mean a TBCC approach? RDE? Something altogether different?

I also took that to mean that the customer thinks there is operational value in going higher than Mach 5. For me this maybe hints that in a world where everyone can see you coming, systems that require a hugely sophisticated AD network, near perfect execution and probably some non trivial luck to defend against seem like a good, if someplace obvious, place to explore solutions.
 
Scott Kenny said:
With the speed and height the launch crews had to be perfectly positioned. The slightest turn and throttle change would put the Blackbird outside the engagement envelope by the time the missile arrived at 80,000ft.

IIRC it was Brian Shul who said that Blackbird SOP was to turn slightly and push the throttles up when the missile warning system reported a launch.
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I've heard from others in the community that Shul is a PNG? On the other hand, the issue with "needs to be perfectly placed" is that you can do that more easily if you know where they're going (because you know the targets).

SA-5 was designed with XB-70 as the reference threat. IIRC the envelope was fairly substantial (80-160km iirc) even for 35km and 1200m/s. It's a pretty known quantity these days, and is part of why SRs used side looking sensors and didn't overfly the USSR. The flip side is that an SA-5 site is the size of a small town, and about the same population, but it's workable.

Anyway, to stay on topic, just altitude and range aren't the magic ticket for the future. It helps, but networked Radars that can forward pass missiles and a host of other things mean that I think a mix of speed, stealth, and a big defensive tool kit are the path forwards.
 
Training_Dummy said:
I also took that to mean that the customer thinks there is operational value in going higher than Mach 5. For me this maybe hints that in a world where everyone can see you coming, systems that require a hugely sophisticated AD network, near perfect execution and probably some non trivial luck to defend against seem like a good, if someplace obvious, place to explore solutions.
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And then promptly die from sticker shock, ensuring that the proposed systems never get built.



whatismoo said:
On the other hand, the issue with "needs to be perfectly placed" is that you can do that more easily if you know where they're going (because you know the targets).

SA-5 was designed with XB-70 as the reference threat. IIRC the envelope was fairly substantial (80-160km iirc) even for 35km and 1200m/s. It's a pretty known quantity these days, and is part of why SRs used side looking sensors and didn't overfly the USSR. The flip side is that an SA-5 site is the size of a small town, and about the same population, but it's workable.
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Thing is, the range and cross-range boost you get from starting a weapon comparable to SRAM at M3 and 80,000ft is such that the SA-5 base needs to be some 500nmi/1000km uprange of the target to be able to intercept the bomber before weapons separation.

It forces the defender to install SA5 sites ~50km apart at something like 600nmi/1200km from the targets and fire enough missiles to ensure that one or two will still be within envelope while the Blackbird bomber makes their turns. How expensive is an SA5 site? How many missiles are needed to successfully engage like that?

What happens when you take a weapon like HACM or ARRW, that have a 1000+km range from a subsonic launch at 30-50kft, and launch them fast and high? How much range does that add? Let's be nice and say it only doubles the range, instead of being an order of magnitude improvement like with SRAM.

Now that ring of SA5 sites every 50km needs to be at least 1200nmi/2400km out from the targets to engage the bombers. Or you're reduced to shooting SA5s at individual missiles.



whatismoo said:
Anyway, to stay on topic, just altitude and range aren't the magic ticket for the future. It helps, but networked Radars that can forward pass missiles and a host of other things mean that I think a mix of speed, stealth, and a big defensive tool kit are the path forwards.
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Fully agreed here.
 
whatismoo said:
I've heard from others in the community that Shul is a PNG? On the other hand, the issue with "needs to be perfectly placed" is that you can do that more easily if you know where they're going (because you know the targets).

SA-5 was designed with XB-70 as the reference threat. IIRC the envelope was fairly substantial (80-160km iirc) even for 35km and 1200m/s. It's a pretty known quantity these days, and is part of why SRs used side looking sensors and didn't overfly the USSR. The flip side is that an SA-5 site is the size of a small town, and about the same population, but it's workable.

Anyway, to stay on topic, just altitude and range aren't the magic ticket for the future. It helps, but networked Radars that can forward pass missiles and a host of other things mean that I think a mix of speed, stealth, and a big defensive tool kit are the path forwards.
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Scott Kenny said:
And then promptly die from sticker shock, ensuring that the proposed systems never get built.




Thing is, the range and cross-range boost you get from starting a weapon comparable to SRAM at M3 and 80,000ft is such that the SA-5 base needs to be some 500nmi/1000km uprange of the target to be able to intercept the bomber before weapons separation.

It forces the defender to install SA5 sites ~50km apart at something like 600nmi/1200km from the targets and fire enough missiles to ensure that one or two will still be within envelope while the Blackbird bomber makes their turns. How expensive is an SA5 site? How many missiles are needed to successfully engage like that?

What happens when you take a weapon like HACM or ARRW, that have a 1000+km range from a subsonic launch at 30-50kft, and launch them fast and high? How much range does that add? Let's be nice and say it only doubles the range, instead of being an order of magnitude improvement like with SRAM.

Now that ring of SA5 sites every 50km needs to be at least 1200nmi/2400km out from the targets to engage the bombers. Or you're reduced to shooting SA5s at individual missiles.




Fully agreed here.
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Sure, SR-71/SRAM would have been quite a monster, but it's also not impossible to work up an interceptor / SAM force that could work against it. On the other hand, this is why I really want SRAM-3! Or SRAM-2-2?
 
Scott Kenny said:
What happens when you take a weapon like HACM or ARRW, that have a 1000+km range from a subsonic launch at 30-50kft, and launch them fast and high? How much range does that add? Let's be nice and say it only doubles the range, instead of being an order of magnitude improvement like with SRAM.
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You won't get anything like the same improvement from an air-breather - and that's assuming a high speed/high altitude launch doesn't just melt the thing.
NMaude said:
If it had gone into production the aircraft's tri-services designation would've been the B-12A.
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The A-12 family was always weird for that kind of thing, presumably in part because of classification.

'F-12' wasn't actually assigned in the tri-service scheme, it was a Lockheed designation made official before the tri-service scheme was introduced. It may even have predated the F-110 and F-111 designations, making it a candidate for the F-109 slot...

'SR-71' meanwhile was in the USAF's 1924 bomber sequence, despite being ordered after the tri-service scheme was introduced, but didn't carry the 'B'.
 
Scott Kenny said:
IIRC, ASALM was not significantly bigger than SRAM. It may have been wider/deeper, but it still fit into more or less the same "1/8 of a CSRL" slot.
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SRAM didn't go on the CSRL, and I'm more interested in sticking it in the slot of a 2000lbs JDAM...
 
whatismoo said:
Sure, SR-71/SRAM would have been quite a monster, but it's also not impossible to work up an interceptor / SAM force that could work against it. On the other hand, this is why I really want SRAM-3! Or SRAM-2-2?
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Or ASALM. Faster than SRAM with more range than SRAM 2. And also would have worked from the Blackbird.
 
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How much could the blackbird based bomber have carried?
 
NMaude said:
IIRC the proposed B-12A would've carried four SRAM As.
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Which is a pretty pitiful payload.

I think it’s worth pointing out that you can have a subsonic bomb truck or a super cruiser with much more limited payload, but you can not have both without a high risk of cancellation (see NGB) or extremely high unit cost which limit build rates.

Again I question: what does 100-200 miles of super cruiser buy you in terms of protection, or if we are going Mach 3 plus, does that not mean B-21 is the cheaper platform with more range and payload?
 

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