USAF/US NAVY 6th Generation Fighter Programs - F/A-XX, F-X, NGAD, PCA, ASFS news

[icyplanetnhc (Steve)]

About the only possible benefit that I can see is that they might be able to use existing F-15C/E infrastructure to support the F100s. Frankly, even that is a stretch given that F110s are widespread in the F-16 fleet, and that even aside from the engines, the F-15EX is considerably different from current USAF F-15s in internal structure and mission systems.

I believe the F110-GE-129 has better dynamic thrust than the F100-PW-229, based on the performance differences between the F-16C Block 50 and 52.

 

[FighterJock]

About the only possible benefit that I can see is that they might be able to use existing F-15C/E infrastructure to support the F100s. Frankly, even that is a stretch given that F110s are widespread in the F-16 fleet, and that even aside from the engines, the F-15EX is considerably different from current USAF F-15s in internal structure and mission systems.

I believe the F110-GE-129 has better dynamic thrust than the F100-PW-229, based on the performance differences between the F-16C Block 50 and 52.

It is like the ATF engine competition all over again.

 

[sferrin]

Given that everybody buying Eagles these days is getting them with F110s I'd think that tells the tale. (Then again maybe they're just doing that for commonality with their F-16 fleets.)

 

[bobbymike]

Air Force expecting NGAD acquisition strategy by end of summer
The Next-Generation Air Dominance program office is aiming to complete its acquisition strategy by the end of this summer and is working now to better understand the potential life-cycle cost of the digital century series model as compared to that of legacy aircraft

 

[dark sidius]

Realy good news

 

[bring_it_on]

They seem to be slowly putting together the elements they need to get to Milestone A (assuming this follows the path of a traditional MDAP).

 

[BDF]

I hope that the "digital century series" Roper is championing works out. I'm skeptical that it will work the way he is intending. One of the big problems with the AF's O&M budget is with the large number of small platform fleets. This would seem to exacerbate the problem. Hope I'm wrong.

 

[bobbymike]

I hope that the "digital century series" Roper is championing works out. I'm skeptical that it will work the way he is intending. One of the big problems with the AF's O&M budget is with the large number of small platform fleets. This would seem to exacerbate the problem. Hope I'm wrong.

Would “digital” more mean much internal electronic updates out of the same airframes? I don’t think multiple aircraft types will work

 

[BDF]

Would “digital” more mean much internal electronic updates out of the same airframes? I don’t think multiple aircraft types will work

From what I've read its a rapid development and production initiative. Roper wants to rapidly develop and field smaller batches of airframes. So as new capabilities and technologies mature, say TRL 7 or 8, then a new design is initiated. I think he wants to also look at airframes that have shorter airframe life on them as well. Its a throwback to 50s and the century series of fighters than were rapidly developed and acquired.

 

[bring_it_on]

I hope that the "digital century series" Roper is championing works out. I'm skeptical that it will work the way he is intending. One of the big problems with the AF's O&M budget is with the large number of small platform fleets. This would seem to exacerbate the problem. Hope I'm wrong.

Would “digital” more mean much internal electronic updates out of the same airframes? I don’t think multiple aircraft types will work

The "digital" in the digital century series refers to utilization of digital design tools and the digital thread, Kubernetes and agile software development. What the AF is looking at is developing and funding the capability to rapidly develop high fidelity designs for systems (manned or unmanned) and then trying to bend the cost curve by maturing the design and making manufactering easier and efficient independent (to some extent) of scale. That's the goal or what I've been able to comprehend anyway.

 

[BDF]

The "digital" in the digital century series refers to utilization of digital design tools and the digital thread, Kubernetes and agile software development. What the AF is looking at is developing and funding the capability to rapidly develop high fidelity designs for systems (manned or unmanned) and then trying to bend the cost curve by maturing the design and making manufactering easier and efficient independent (to some extent) of scale. That's the goal or what I've been able to comprehend anyway.

Yes that's essentially my understanding, you've elucidated it better. I hope its viable, we can't keep taking 20yrs to develop a system. That being said, there's considerable skepticism both inside and outside the service that its viable. We certainly need a stand-in penetrator replacement or supplement to the F-22 fleet. Its interesting that CSBA believe it must be a manned standalone system. They content that any UAS that can supplement or support a PCA vehicle will require similar levels of survivability and range; ergo it will be big and expensive. If Roper is right then maybe that UAS stand-in vehicle will be more reasonable in cost for the capability. Time will tell...

 

[In_A_Dream]

Yes that's essentially my understanding, you've elucidated it better. I hope its viable, we can't keep taking 20yrs to develop a system. That being said, there's considerable skepticism both inside and outside the service that its viable. We certainly need a stand-in penetrator replacement or supplement to the F-22 fleet. Its interesting that CSBA believe it must be a manned standalone system. They content that any UAS that can supplement or support a PCA vehicle will require similar levels of survivability and range; ergo it will be big and expensive. If Roper is right then maybe that UAS stand-in vehicle will be more reasonable in cost for the capability. Time will tell...

Also have to think about when the DoD is going to start increasing its misinformation/disinformation campaign to cloud its future developments. There's been enough acknowledgment by defense officials, legislature, and think tanks about how transparent we are with where we are going and that's not always a good thing when someone is trying to +1 you.

 

[BDF]

Why the USAF is keen on car maker know-how for future fighter production

The service wants to mimic the way the car industry makes small improvements to car models year after year using digital design and engineering tools.

www.flightglobal.com

 

[jsport]

Why the USAF is keen on car maker know-how for future fighter production

The service wants to mimic the way the car industry makes small improvements to car models year after year using digital design and engineering tools.

www.flightglobal.com

Could there be an "ideal" scalable airframe and propusulor which generally could not be outpaced for +20yrs which is "peer reviewed" and agreed upon as baseline aircraft? Science not sizzle setting the pace.

 

[Sundog]

Could there be an "ideal" scalable airframe and propusulor which generally could not be outpaced for +20yrs which is "peer reviewed" and agreed upon as baseline aircraft? Science not sizzle setting the pace.

The main problem you run into there is the mission profiles for the U.S. Navy and USAF tend to be vastly different. In general, the Navy wants a fighter that can fly a certain distance from a carrier and then loiter in a racetrack pattern for a couple of hours, but be capable of dashing at supersonic speeds towards a target. Whereas the USAF generally wants an aircraft that can cruise at supersonic speeds and penetrate deep into enemy airspace. Those are very different mission profiles, in terms of what the propulsion needs to do. Now, I'm not saying they couldn't use variations of the same power-plant to do so, but it would still depend on how close the mass flows, etc, are to each other to be able to achieve that much commonality.

I think it will be interesting to see the trades on how much super-cruise and how much subsonic loiter ability the USAF wants, given the pivot to the Pacific.

 

[rooster]

Could there be an "ideal" scalable airframe and propusulor which generally could not be outpaced for +20yrs which is "peer reviewed" and agreed upon as baseline aircraft? Science not sizzle setting the pace.

The main problem you run into there is the mission profiles for the U.S. Navy and USAF tend to be vastly different. In general, the Navy wants a fighter that can fly a certain distance from a carrier and then loiter in a racetrack pattern for a couple of hours, but be capable of dashing at supersonic speeds towards a target. Whereas the USAF generally wants an aircraft that can cruise at supersonic speeds and penetrate deep into enemy airspace. Those are very different mission profiles, in terms of what the propulsion needs to do. Now, I'm not saying they couldn't use variations of the same power-plant to do so, but it would still depend on how close the mass flows, etc, are to each other to be able to achieve that much commonality.

I think it will be interesting to see the trades on how much super-cruise and how much subsonic loiter ability the USAF wants, given the pivot to the Pacific.

But it still seems like you could have a common airframe with different wings like the 35A and C and save billions. Heck you could even divide the production between 2 companies to maintain the industrial base.

I know the USAF wants a super-cruise machine but that doesn't mean it can't fly the navy profile outlined above.

Say what you will about the tomcat versus eagle debate, I think the know-how exits today to build a somewhat common aircraft for both services.

 

[sferrin]

Why the USAF is keen on car maker know-how for future fighter production

The service wants to mimic the way the car industry makes small improvements to car models year after year using digital design and engineering tools.

www.flightglobal.com

So instead of only taking something to D or F, like the F-teens, go all the way to S or more like the F-4, F-104, etc?

 

[sferrin]

Could there be an "ideal" scalable airframe and propusulor which generally could not be outpaced for +20yrs which is "peer reviewed" and agreed upon as baseline aircraft? Science not sizzle setting the pace.

The main problem you run into there is the mission profiles for the U.S. Navy and USAF tend to be vastly different. In general, the Navy wants a fighter that can fly a certain distance from a carrier and then loiter in a racetrack pattern for a couple of hours, but be capable of dashing at supersonic speeds towards a target. Whereas the USAF generally wants an aircraft that can cruise at supersonic speeds and penetrate deep into enemy airspace. Those are very different mission profiles, in terms of what the propulsion needs to do. Now, I'm not saying they couldn't use variations of the same power-plant to do so, but it would still depend on how close the mass flows, etc, are to each other to be able to achieve that much commonality.

I think it will be interesting to see the trades on how much super-cruise and how much subsonic loiter ability the USAF wants, given the pivot to the Pacific.

But it still seems like you could have a common airframe with different wings like the 35A and C and save billions. Heck you could even divide the production between 2 companies to maintain the industrial base.

I know the USAF wants a super-cruise machine but that doesn't mean it can't fly the navy profile outlined above.

Say what you will about the tomcat versus eagle debate, I think the know-how exits today to build a somewhat common aircraft for both services.

The F-14D, with -132s could have made an awesome Strike Tomcat in the vein of the Strike Eagle.

 

[jsport]

I hope that the "digital century series" Roper is championing works out. I'm skeptical that it will work the way he is intending. One of the big problems with the AF's O&M budget is with the large number of small platform fleets. This would seem to exacerbate the problem. Hope I'm wrong.

Would “digital” more mean much internal electronic updates out of the same airframes? I don’t think multiple aircraft types will work

The "digital" in the digital century series refers to utilization of digital design tools and the digital thread, Kubernetes and agile software development. What the AF is looking at is developing and funding the capability to rapidly develop high fidelity designs for systems (manned or unmanned) and then trying to bend the cost curve by maturing the design and making manufactering easier and efficient independent (to some extent) of scale. That's the goal or what I've been able to comprehend anyway.

is Kubernetes going to be safe given who the developer is? These designs must be remain TS or above clearance.

 

[BDF]

So instead of only taking something to D or F, like the F-teens, go all the way to S or more like the F-4, F-104, etc?

Literally like the F100, F-101 etc. Roper has spoken about buying as few as a wings worth of jets at a time. He want's the AF to be more "like a tech company" trying to rapidly innovate and push out a product, with perhaps a small production run, then as new technologies emerge, start production on the next system. They may have quite a bit in common in terms of subsystems but as you iterate further down away from the first design, the commonality may be substantially reduced. So we may see a hypothetical F-36 in 2032 (fingers crossed!), then maybe a F-37 in 2036, a F-38 in 2040 etc etc. It sounds innovative but as I've mentioned, one killer for the AF's budget has been the O&M Our O&M budget is now 35% of the topline which is insane. We have dozens on small fleet types n the inventory which really drives up budget. This doesn't address some other considerations with such small fleets , such as combat readiness , MCR rates, the training pipelines for pilots and maintainers etc.

 

[sferrin]

So instead of only taking something to D or F, like the F-teens, go all the way to S or more like the F-4, F-104, etc?

Literally like the F100, F-101 etc. Roper has spoken about buying as few as a wings worth of jets at a time. He want's the AF to be more "like a tech company" trying to rapidly innovate and push out a product, with perhaps a small production run, then as new technologies emerge, start production on the next system. They may have quite a bit in common in terms of subsystems but as you iterate further down away from the first design, the commonality may be substantially reduced. So we may see a hypothetical F-36 in 2032 (fingers crossed!), then maybe a F-37 in 2036, a F-38 in 2040 etc etc. It sounds innovative but as I've mentioned, one killer for the AF's budget has been the O&M Our O&M budget is now 35% of the topline which is insane. We have dozens on small fleet types n the inventory which really drives up budget. This doesn't address some other considerations with such small fleets , such as combat readiness , MCR rates, the training pipelines for pilots and maintainers etc.

With all the work gone into improving reliability, maintainability, etc. has it even made a dent? Or has added complexity sucked all that up? Compare say an F-4 to an F-35 in those regards.

 

[BDF]

With all the work gone into improving reliability, maintainability, etc. has it even made a dent? Or has added complexity sucked all that up? Compare say an F-4 to an F-35 in those regards.

Its not clear to me at least what impact those factors may have or had. CSBA did an analysis of the problem and determined that fleet age and sophistication have no correlation. What is interesting is that the MITRE report and CSBA did find a correlation between fleet size and total ownership costs (fixed + variable costs.) IOW as the fleet got smaller, the cost per unit (TAI) goes up. The equation is TOC = $160M X Sqrt(TAI). So as an example we're at 183 F-22s and our TOC for the fleet is $160 X Sqrt(183)= $2.1B. Or $11.8M per jet. If we get the F-35 fleet up to the full 1,765 buy for the AF, that's a TOC of $6.7B or $3.8M per jet.

Now looking forward to Roper's idea of small fleet buys, if we look at 4 wings worth of jets and break it down into 4 distinct types the TOC is $1.36B per wing or $18.8M per jet. For the total fleet of 288 that's $5.4B. If we were to buy two types that is a TOC of $1.9B each ($13.3M per jet) for a total $3.8B for the same 288 jets. If it we just buy one type and build 288 of them it drops to $2.7B or $9.4M per jet. So splitting the buy into 4 distinct types doubles the TOC for the same amount of airframes if we were to buy just one type. This is also indicative of why we need to accelerate the F-35 buy in addition to getting unit cost down from manufacturing efficiencies. I'd also argue we shouldn't be buying F-15EXs for the same reason, despite their supposed lower operating costs.

 

[trose213]

So instead of only taking something to D or F, like the F-teens, go all the way to S or more like the F-4, F-104, etc?

Literally like the F100, F-101 etc. Roper has spoken about buying as few as a wings worth of jets at a time. He want's the AF to be more "like a tech company" trying to rapidly innovate and push out a product, with perhaps a small production run, then as new technologies emerge, start production on the next system. They may have quite a bit in common in terms of subsystems but as you iterate further down away from the first design, the commonality may be substantially reduced. So we may see a hypothetical F-36 in 2032 (fingers crossed!), then maybe a F-37 in 2036, a F-38 in 2040 etc etc. It sounds innovative but as I've mentioned, one killer for the AF's budget has been the O&M Our O&M budget is now 35% of the topline which is insane. We have dozens on small fleet types n the inventory which really drives up budget. This doesn't address some other considerations with such small fleets , such as combat readiness , MCR rates, the training pipelines for pilots and maintainers etc.

It's about getting to the next F-4. They're trying to build small batches of planes in an iterative process, until one actually lives up to the hype. I wonder how many export opportunities there will be.

 

[TomcatViP]

@BDF : I think you forgot to factor-in the effect of having shared sub-systems and software across different airframe. That will translate into substantial cross-fleet economies. IMOHO you should add a K factor into the above equation and add fleet numbers:

With Ni the N number of airframe of type i fleet, TOC = $160M * K*Sqrt(N1+N2+...+Nn).
With K a function of the level of cross-integration of sub-systems (K>1 and lim(K) =1 when integration is fully optimal). K is an indice of Quality.

 

[BDF]

@BDF : I think you forgot to factor-in the effect of having shared sub-systems and software across different airframe. That will translate into substantial cross-fleet economies. IMOHO you should add a K factor into the above equation and add fleet numbers:

With Ni the N number of airframe of type i fleet, TOC = $160M * K*Sqrt(N1+N2+...+Nn).
With K a function of the level of cross-integration of sub-systems (K>1 and lim(K) =1 when integration is fully optimal). K is an indice of Quality.

So I didn't derive this equation, this came from Todd Harrison from a CSIS lecture featuring a panel with members from the CSBA and MITRE orgs. You are certainly right that one should have a coefficient in there to account for that but I haven't seen any data on that and would thus be speculative. They did discuss this however and it sounded like the cost savings are minimal.

Just messing around with some numbers, the annual TOC for the F-15C and F-22A fleets is currently $4.6B. For the same TOC, we could have 832 Raptors. Granted the acquisition costs would have to be factored in but one point they made during the lecture is that we never had a spike in acquisition for the introduction of 5th Gen fighters. We're spreading it out over decades instead of trying to acquire them rapidly. This is what killed the F-22. The production line was designed for 48, but could run effectively as low as 36 but we went on to average 20/yr. We need to get F-35's annual numbers up.

 

[BDF]

This summer could be a make or break moment for US Air Force’s next fighter program

The Next Generation Air Dominance program is set to have a finalized acquisition strategy within the next few months.

www.defensenews.com

 

[zebra159357]

You can watch the video from which those articles are sourced. Digital century series talk starts on 30 minute mark.

 

[TomcatViP]

Around 27':
"Next Gen pilot will Instinctively understand AI"
This is excellent when you think at it. Both humans and machine capitalizing on shared expectations to make AI relevant into the operational sphere "as a synergistic team".

Amazing also that the digital plane achievement milestone praised so much by Roper was reached on the T7 with the Swedes and not the Frenches with Dassault.
OK Swedes have one of the best multiphasics software outhere with Comsol but still.

 

[Hood]

You have to wonder how much the analysts and staff officers of today actually understand about historical programmes.
The Century series were built en mass, only two grossed under 800 airframes; around 300F-104s for the USAF and 342 F-106. So they could back up multiple types with some numbers for spreading production and service costs.
Of course four of the Century series were cancelled outright (F-103, F-107, F-108, F-109) and F-106 was an extension of the F-102, so really the Century series were a mixed bunch at best and designed for a range of roles and were remarkably adaptable for other roles, quite fortuitously for some of them. They also covered the outputs of five (six if you count the Bell F-109) companies, so there was research and development in depth.

All this sounds much like open-architecture, which I thought had been around for the last 20-30 years? Aircraft like the F-15, F-16 and F/A-18 have already accepted everything thrown at them in terms of new engines, avionics and materials. They are nothing like their A-models. I thought modern aircraft were always designed this way, to accept new subsystems with relatively little reworking? What this actually sounds more like is building monopolies so that certain companies will always supply certain items of equipment for the entire inventory.

The big worry of course is that the modern consumer industry loves 'built-in obsolesce' and talk of a digital-century series built on small increments with scrapping rather than upgrading could well lead to this if they are not careful.

 

[sferrin]

You have to wonder how much the analysts and staff officers of today actually understand about historical programmes.
The Century series were built en mass, only two grossed under 800 airframes; around 300F-104s

More like 2,578, the most numerous of the Century series.

 

[sublight_]

Say what you will about the tomcat versus eagle debate, I think the know-how exits today to build a somewhat common aircraft for both services.

Yes, but unfortunately there are the behind the scenes politics, the inter-service rivalries, and the personal vendettas which are the ultimate slient weapon, and can destroy any good program or platform in its path. The only way around this for F35 was to have suppliers in almost every congressional district of the USA.

 

[TomcatViP]

More like 2,578, the most numerous of the Century series.

Phantom production ran from 1958 to 1981, with a total of 5,195 built, making it the most produced American supersonic military aircraft.

Wiki (because 4=110 back in the time)

 

[sferrin]

More like 2,578, the most numerous of the Century series.

Phantom production ran from 1958 to 1981, with a total of 5,195 built, making it the most produced American supersonic military aircraft.

Wiki (because 4=110 back in the time)

The F-4 wasn't part of the Century series anymore than the F-111 or F-117 were.

 

[mkellytx]

More like 2,578, the most numerous of the Century series.

Phantom production ran from 1958 to 1981, with a total of 5,195 built, making it the most produced American supersonic military aircraft.

Wiki (because 4=110 back in the time)

The F-4 wasn't part of the Century series anymore than the F-111 or F-117 were.

Airframe: First Flight: Service Entry:
F-100 1953 1954
F-101 1954 1957
F-102 1953 1956
F-104 1954 1958
F-105B 1956 1958
F-107 1956 N/A
F4H-1/F-110 1958 1960

One could argue... It was only 2 years separate from the Thud and Zipper, and contemporaneous with D model Thud.

 

[sferrin]

More like 2,578, the most numerous of the Century series.

Phantom production ran from 1958 to 1981, with a total of 5,195 built, making it the most produced American supersonic military aircraft.

Wiki (because 4=110 back in the time)

The F-4 wasn't part of the Century series anymore than the F-111 or F-117 were.

Airframe: First Flight: Service Entry:
F-100 1953 1954
F-101 1954 1957
F-102 1953 1956
F-104 1954 1958
F-105B 1956 1958
F-107 1956 N/A
F4H-1/F-110 1958 1960

One could argue... It was only 2 years separate from the Thud and Zipper, and contemporaneous with D model Thud.

Uh, it was a NAVY plane. The Century series were USAF. The only thing "Century Series" about the F-4 was the painted "F-110" slapped on the side for a bit. May as well call the MiG-21 a Century Series aircraft too because the USAF called it the YF-110 as well:

4477th Test and Evaluation Squadron - Wikipedia

en.wikipedia.org

 

[Lc89]

Couldn't they use the piece cannibalization method for Digital Century Series? If there is commonality between platforms, it could save money.

 

[bobbymike]

Congress has questions about the Air Force’s and Navy’s next-generation fighter programs

The House Armed Services Committee wants an independent review of the Navy's and Air Force's Next Generation Air Dominance programs.

www.defensenews.com

———————————————————
But HASC intends to fence off 85 percent of the fiscal 2021 funding requested for the NGAD until the committee receives an independent review performed by the Pentagon’s director of cost assessment and program evaluation, according to the Tactical Air and Land Forces Subcommittee’s markup of the FY21 defense policy bill.

 

[dark sidius]

Congress has questions about the Air Force’s and Navy’s next-generation fighter programs

The House Armed Services Committee wants an independent review of the Navy's and Air Force's Next Generation Air Dominance programs.

www.defensenews.com

———————————————————
But HASC intends to fence off 85 percent of the fiscal 2021 funding requested for the NGAD until the committee receives an independent review performed by the Pentagon’s director of cost assessment and program evaluation, according to the Tactical Air and Land Forces Subcommittee’s markup of the FY21 defense policy bill.

Is it a normal process or something bad for the futur program ?

 

[latenlazy]

@BDF : I think you forgot to factor-in the effect of having shared sub-systems and software across different airframe. That will translate into substantial cross-fleet economies. IMOHO you should add a K factor into the above equation and add fleet numbers:

With Ni the N number of airframe of type i fleet, TOC = $160M * K*Sqrt(N1+N2+...+Nn).
With K a function of the level of cross-integration of sub-systems (K>1 and lim(K) =1 when integration is fully optimal). K is an indice of Quality.

This all sounds good in theory until you realize the standardized frameworks and interfaces you need to get your modularizable solution can end up imposing their own performance constraints, especially for hardware with a lot of integrated dependencies. There are serious problems in trying to adapt software development models, which tend to benefit from open ended and adaptive development paths for meeting performance parameters (both as a function of their level of abstraction and in no small part thanks to excess of computational power now available), as well as fast iterative workflows (updating code is a much less burdensome task than tinkering with physical hardware) to hardware domains where constraints are physically based and hitting performance targets require specific integration dependencies that are closed looped.

Often times what ends up happening when these models from software engineering are applied too zealously to hardware is that you end up compounding the cost problem when you find yourself spending time not so much updating components as you are wasting time trying to update the original frameworks to enable greater capability for future technology that works differently from the protocols that the framework was originally configured for. Modular iterative approaches are essentially vulnerable to greater technical debt that accumulates as the framework ages, and this technical debt tends to be a lot more costly when what you’re trying to fit together are complex physical objects rather than abstract logic represented by lines of code. This doesn’t mean that these kinds of iterative open ended program concepts can’t work, but there are a lot of ways they can go horribly wrong, amplifying the time, performance, and resource problems that were originally meant to be solved by its adoption.

 

[jsport]

@BDF : I think you forgot to factor-in the effect of having shared sub-systems and software across different airframe. That will translate into substantial cross-fleet economies. IMOHO you should add a K factor into the above equation and add fleet numbers:

With Ni the N number of airframe of type i fleet, TOC = $160M * K*Sqrt(N1+N2+...+Nn).
With K a function of the level of cross-integration of sub-systems (K>1 and lim(K) =1 when integration is fully optimal). K is an indice of Quality.

This all sounds good in theory until you realize the standardized frameworks and interfaces you need to get your modularizable solution can end up imposing their own performance constraints, especially for hardware with a lot of integrated dependencies. There are serious problems in trying to adapt software development models, which tend to benefit from open ended and adaptive development paths for meeting performance parameters (both as a function of their level of abstraction and in no small part thanks to excess of computational power now available), as well as fast iterative workflows (updating code is a much less burdensome task than tinkering with physical hardware) to hardware domains where constraints are physically based and hitting performance targets require specific integration dependencies that are closed looped.

Often times what ends up happening when these models from software engineering are applied too zealously to hardware is that you end up compounding the cost problem when you find yourself spending time not so much updating components as you are wasting time trying to update the original frameworks to enable greater capability for future technology that works differently from the protocols that the framework was originally configured for. Modular iterative approaches are essentially vulnerable to greater technical debt that accumulates as the framework ages, and this technical debt tends to be a lot more costly when what you’re trying to fit together are complex physical objects rather than abstract logic represented by lines of code. This doesn’t mean that these kinds of iterative open ended program concepts can’t work, but there are a lot of ways they can go horribly wrong, amplifying the time, performance, and resource problems that were originally meant to be solved by its adoption.

after reading this, it once again becomes a big issue...Why manned craft adding continual complication and cost?