New Mars Forums

tahanson43206,

Gas turbines and heat recuperators that are 10X smaller than steam equivalents are not an "almost negligible advantage".  All that metal and machining costs real money.  Even if the steel grades used in a steam turbine are modestly cheaper, they're not 10X cheaper than the steels used in SCO2 turbines.  The difference in sizing of the major pieces of plant equipment are "the entire city block" vs "one house on the block".  All the stuff in one house can be crammed into a Starship and shipped to Mars.  Shipping an entire city block's worth of equipment is not practical.  There is no reality-based scenario where any kind of steam turbine comes close to out-performing the SCO2 turbine.  It's not cheaper, it's not smaller, it's not easier to repair, it's not easier to assemble and disassemble for transport, it's not faster to ramp-up and ramp-down to load-follow, and it's definitely not minimizing CO2 emissions.

China National Nuclear Corporation already has their first grid-connected SCO2 power plant in Guizhou.  It's very small, only a pair of 15MW waste heat SCO2 turbo-generators, but that waste heat was otherwise at the wrong temperature for using steam, because it was waste heat from steel making.  Would you rather they burn more or less coal?

The first generation of any new technology will take time to establish its footing.  I don't judge combustion engines on the relative success or failure of Ford's Model T.  That engine and vehicle was a joke compared to any modern turbocharged inline 4 cylinder engine in a mini SUV.  Modern I4's produce as much horsepower and torque as a muscle car era V8, at less than half the weight and displacement.  Modern family vehicles are only possible because their turbo I4's deliver V8 torque and power at half the size and weight, all day long.

This article does a good job of indicating exactly how the Allam-Fetvedt Cycle works, why it's a significant improvement over what we presently have in the form of steam and conventional gas turbines, and why Net Power is pursuing it, despite cost overruns and delays, which are related to problems with the Air Separator Units, rather than the SCO2 gas turbines and heat exchangers:
This Power Plant Runs on CO2

One of the reasons it's "good far Mars", is that it recaptures and recirculates the exhaust effluent, instead of dumping it in the atmosphere.  It's the first power plant to demonstrate it can do that economically, meaning so much of the power isn't consumed trying to recompress the CO2 for storage that it's not worth the cost and energy involved.  It's a CO2 recycling system deliberately built into the power plant as an integral design feature, rather than as an afterthought.  Those Air Separator Units will also become critical life support infrastructure pieces for a Mars colony.

If it's not apparent yet from the photos provided above, all the "real money" spent on the F-35 program was dumped into the sensors and software to provide a "bubble" of spatial awareness, plus the computer program telling the pilot what to pay attention to and what can be safely ignored.  That's why it took so long to fully develop.  It had almost nothing to do with the flight control software or engine or airframe, even though all of those things are their own little technological marvels.  There is no other aircraft in existence that provides the same level of situational awareness as the F-35, to include the F-22.

We don't pay lip service to the idea of going back and fixing defects in components or software, either.  When we discover that something is broken, we commit to solving the problems until it "just works".  Denying that problems exist or hoping your enemy doesn't discover the flaws in the system is not an acceptable way to do business.  To their credit, Lockheed-Martin has worked with their team of contractors to find and fix all observed airframe, engine, and software problems.  Does it take them longer than we'd like it to?  Yes.  Is it cheap?  No.  Does it mean we have confidence that the platform is ready for combat by the time it sees combat?  Absolutely.  All effort is now directed at future enhancements and meeting the production (16 new tails per month) and repair schedules.

If you are not aware of what is going on around your plane at all times, against anyone who has a plane with the F-35s capabilities or modern air defense systems, you're as good as dead.  If someone hasn't come along to kill you yet, that's because you had no serious effect on their operations.  To this very day, most pilots who were shot down were either completely unaware that they were under attack, or so lacking in basic information about the direction that the threat was coming from that they couldn't do anything about it.

Here in the West, we spend so much time and effort training fighter pilots that we cannot afford to forfeit their lives, simply because some electronic gadget that could provide threat and target awareness wasn't installed in their jet due to cost-cutting measures.  We need them to survive their first 5 to 10 combat missions to gain the experience required to operate in the new threat environment.

If they fly prior generations of combat jets, then half of them get shot down on every mission they fly against enemy air defenses and fighters in virtually all of the war games conducted during the past 25 years.  Statistically speaking, that means none of them live long enough to see the end of their first combat deployment.  Nobody is left to train the next replacement group of pilots.  Worse than that, the production rates for modern combat jets are so low that there won't be replacements available in any meaningful period of time.  Absent complete destruction of enemy air defenses, an entire squadron of Vipers or Strike Eagles or Rafales or Typhoons could be lost on a single mission over heavily defended territory.  There's no way to conjure up replacement jets and aircrew.  Anyone who isn't already in the training pipeline is unlikely to see action before the war is over, and there are never enough tails once the shooting starts.

China is producing about 200 J-20s per year as of 2025, so only 16 planes per month spread across 5 different production lines.  Even for China it would now appear that there's a hard limit on resources devoted to any one piece of military equipment.  Russia hasn't even come close to replacing combat-related aircraft losses in the Ukraine War.  There's no reason to believe that America, China, Russia, or anyone else for that matter, ever could.  These combat jets are no longer Aluminum sheet metal bent into shape and riveted.  The tooling to make the airframes runs well into the tens of millions of dollars, and their engines are "OMG" expensive.  Trained and efficient production line workers cannot be summoned from the talent pool, either.  If money is no object, then sure, we could spend a major portion of GDP to produce more jet engines, but that is now as unrealistic as thinking you can afford to lose half your fighter jet squadron per mission.

Oddly enough, the Chinese are also starting to accept that this is how modern air combat really works.  They have just as many problems with training / retaining new pilots and meeting production schedules as we do.  They're not churning out their new J-20s or J-35s any faster than we are, and for the same reason.  These machines are hideously complex.  Each one is now so costly as to almost become a strategic asset.  Losing them to human error, inadequate training, or limited survivability in the threat environment are no longer viewed as practical, even during a war.  If you fail to swiftly establish air superiority and use it to wipe out the enemy's war machines, then you'll fight a desperate grinding war of attrition until one side breaks under the constant pressure, and that process could take years.  All the while, you're losing young men at frightening rates, money is being burned like there's no tomorrow, and in a very real sense, the opportunity cost of having the war drag on is more economically damaging than the deaths and national debts because it can keep taking from your people generations after the war is over.  I've yet to see ships produced quickly and effectively when the shipyard was under cruise missile attack, either.  The WWII production methods don't work with modern weapon systems.  The "quick and dirty" substitute weapons are iron bombs and artillery shells, which means you have to get close enough to use them.  Whoever is able to control the skies is going to dictate which pieces of military equipment remain usable.  Knock out the oil refineries or power plants and the entire war machine grinds to a halt.  Here in America, we've determined that we cannot afford to allow that to happen to us, so everything we develop for the air power domain is to ensure that happens to our enemies first.  Attrition warfare is a losing proposition, as both WWI and WWII already proved.

Lest we forget our automotive history, here are a few images of the Chrysler recuperated gas turbine car engine:

Engine installation at the factory:

Flow Path / Operating Diagram:

Recent photos of the engine and transmission:

Older photo of the intake side:

Engine Diagram:

Vehicle Powertrain Diagram:

Chrysler went through 7 generations of gas turbine engine technology in an attempt to make the tech reliable, durable, affordable, and fuel efficient enough to be worth manufacturing for the general public.  Unfortunately, their efforts never resulted in a saleable product.  When Lee Iacocca took the bailout from Uncle Sam, part of the deal was to kill this program because Chrysler sunk a huge amount of their R&D budget into its development.

General Motors had their own turbine powered concept car, but again, development was insufficient to result in a saleable product.

Jaguar attempted a gas turbine electric powered car, also amounting to nothing.  A few prototypes were built and tested, nothing more.

As an electric hybrid using a micro gas turbine + small battery + electric traction motors, the concept actually makes a lot more sense.

The LearJet bubbas worked on this thing:

In the 1960s, everyone thought gas turbines would power everything:

Bill Bessler built a steam powered car for General Motors in the 1970s.  It's primary claim to fame was dramatically reduced smog emission prior to catalytic converters, but fuel economy was only 15mpg.  Dutcher worked on a steam powered car for California in the 1970s as well.

US DoE tested a Stirling engine car in the 1980s to early 1990s:

Could we get better performance from gas turbine an external combustion engines using modern FADEC technology?

Probably.

Will they ever be as cheap and cost-effective as piston engines at output below about 550hp or so?

Possibly, but not likely.  The materials and manufacturing methods used to deal with the heat are expensive, full stop.

tahanson43206,

I'm not sure if he understands how significant the friction and Reynolds losses will be in the sort of machine he's proposing.  Have you noticed that all geared turbofans use reduction drives to power the fan or prop, but nobody puts anything like what he's envisioning in the hot section of the turbine where the hot gas is expanding?  Gears, hinges, and whatnot in the part of the machine that's hot enough to melt Iron typically don't last very long.  The only reason hot section components don't melt in modern turbines is that they use boundary layer cooling, thermal barrier coatings, and smooth flow through the core.

If someone thought they could extract significant additional power, they'd not-so-simply work out how to make a mechanical advantage device work.  Even in the context of steam turbines operating at more survivable temperatures, said mechanism is still likely to fail.  There are basic fluid and thermodynamic phenomenon that would "sap power" from the device he wants to create, even if the mechanical bits don't overheat and warp.

While it may not be technically impossible, there are easier and simpler ways to extract more power from expanding gas.  This kinda reminds me of the Librato (sp?) engine.  That guy actually built one, and technically it was more thermodynamically efficient than a conventional diesel piston engine due to the mechanical advantage the mechanism provided, but it also vibrated itself to death when scaled up, even though it kinda sorta worked at a very small scale.  There have been all manner of novel mechanical advantage engines designed to extract additional power, but most of them end up being more trouble than they're worth.

Whenever engineers want to increase energy conversion efficiency, they increase the temperature delta and/or add another row of blades to the expansion turbine to extract more power.  They stop when the mass / size of the expansion turbine becomes impractical, and instead use the hot exhaust effluent to flash water to steam to run a geared steam turbine in a secondary power transfer loop.  This is a good system for a stationary power plant of even a ship with a high quality heat source, such as a gas turbine engine.

Chrysler used a large recuperator stage to make their automotive gas turbine more efficient because more turbine blades were and are expensive, but had to stop when the thing filled the engine bay.  They also used "blade disks" or "blisks" vs traditional individual turbine blades, because a blisk is a single near-net-shape casting which minimizes finishing machining operations.  At 410lbs, the turbine was still lighter than an all-Iron V8, but not by a lot, it burned a more expensive fuel, even though it could technically run on Chanel No 5, and on top of that it was made from precision machined refractory metals that could not be repaired by shade tree mechanics.  Fuel economy at idle with a gas turbine is horrific, even today.  The turbine engine ultimately made 130hp and 425-450lb-ft of torque.  The torque was phenomenal for the time, so acceleration to highway speeds was very respectable, but total power was also very limited.  Once you're on the highway, passing a slower driver is more difficult.  It would've been fine for 55mph, but passing someone at 70mph going up a hill would be difficult.  Unfortunately, all of the materials tech added up to an engine that was much more expensive than an equally capable gasoline fueled piston engine.  I think it would still be more expensive using modern manufacturing tech.  Modern piston engines are mostly cast Iron moving bits / Aluminum for blocks or heads or covers / plastic for intake manifolds since it heats soaks less than Aluminum.  Those are the cheapest and lightest materials that get the job done, and they do the job admirably.

The all-Aluminum LS1 V8 engine from the turn of the century made 305-350hp and 335-365lb-ft of torque.  The most modern 6.6L L8T version of the LS engine architecture makes 401hp and 464lb-ft of torque.  These all-Aluminum engines also weigh about 400-425lbs, fully dressed, without fluids.  They're weight-equivalents of that Chrysler turbine, about the same size, make considerably more power, burn less fuel, burn gasoline instead of kerosene or diesel, and don't cost nearly as much to manufacture as a gas turbine because nearly every part of the engine is a casting or powdered metal part or plastic.  Modern casting and powdered metallurgy is so good that it's considerably stronger than the more expensive low-alloy steel forgings from the muscle car era.  The factory forged crankshafts and connecting rods from the muscle cars are not as strong as the modern stuff.  We used so many forgings for so long for sake of consistency of forged parts.

We quit considering small gas turbine engines because of the aforementioned idle fuel consumption problem combined with the fact that none of them are significantly lighter or smaller than equivalently powerful piston engines.  Modern turbocharged I4s are cranking out 200-250hp and 250-350lb-ft of torque and only weight about 250lbs with fluids and accessories.  Gas turbines can be made lighter, but only when idle fuel economy, service life, and cost considerations are tossed out the window.  Gas turbines still work great for mostly steady-state applications like aircraft and electric power plants.

If both range and supersonic speed are all-important, then why was the F-111 never adopted by Canada?

The TF-30 engines are significantly larger in diameter than the F-135, so a pair of F-135 engines should make it climb like the F-14D.  I've never heard anyone claim that a Tomcat couldn't climb well.  F-111F's initial climb rate was almost 26,000fpm, so increasing thrust by 71% should provide a 45,000fpm initial climb rate at 100,000lb MTOW, same as the F-14D.  It'll reach 40,000ft in less than 3 minutes.  At a realistic combat weight with full internal fuel and weapons only, it'll "only" climb as fast as any existing fighter.

While this proposed long range interceptor technically has sufficient thrust to hit Mach 3 at altitude, we'll ignore such fanciful nonsense in favor of an airframe that still maneuvers like a world class air superiority fighter because we don't have to make the entire airframe out of refractory metals to cope with Mach 3 heating.

The F-14D carried 2,916 gallons of internal and external fuel.  In combat configuration, F-14D was limited to 6.5g, whereas the F-111F was limited to 7.33g.  Using modern high strength steels and composites, a modernized F-111 would be an 8g capable plane with full internal fuel and air-to-air weapons loadout.  Empty weight would be nearly identical to the F-14D.  A notional CF-111 Thrust-to-Weight Ratio (TWR) with 5,043 gallons of internal fuel vs max fuel, 8X internal Peregrine, and 500lbs for the crew would put it at 1.08:1, which is sufficient to accelerate in a vertical climb after takeoff.

This notional CF-111 would be equipped with 2X F-135 engines, regular ejection seats for the crew vs the historical crew escape pod, and 8X Peregrines in the internal weapons bay.  The wing and fuselage skins would be CFRP, same as all other modern fighters.  This puts empty weight at the same as the F-14D Tomcat.

Empty Weight TWR Chart
CF-111: 1.97:1
Typhoon: 1.67:1
F-15EX (no CFTs): 1.66:1
F-22A: 1.62:1
Su-57: 1.57:1
Rafale-C: 1.57:1
Su-35S: 1.53:1
F-35A: 1.47:1
Gripen-E: 0.94-1:1

CF-111 combines "all the thrust" with "all the fuel", because you're not going anywhere without fuel.  It beats every modern and historical tactical fighter in existence at the TWR game by a considerable margin.

Did I mention that the CF-111's nose would have more space for a larger AESA radar array than any other tactical fighter?

The APG-77 X-band radar supposedly has a detection range of about 510km against a Tu-95, so a 50% larger and more modern / powerful array ought to be able to detect any Russian bomber that the radar has line-of-sight to.

However, more modern fighter jet radars like the APG-81 and APG-85 trade some detection range in favor of image detail:

UC Berkeley - Accelerating Ukraine Intelligence Analysis with Computer Vision on Synthetic Aperture Radar Imagery

Imagine having a fighter jet radar capable of providing very high resolution video imagery of inbound enemy aircraft, so that your interceptor pilot knows exactly what kind of aircraft he's shooting at, rather than simply seeing a "blip" on his screen.

F-22 pilots still see "blips" on their radar, with some limited imaging capability against ground targets, whereas F-35 pilots see this on their radar:

The F-22 pilot can technically "see" at greater distances because its radar operates in a lower frequency band, but has only limited information about what the radar is actually "looking at".

The F-35 pilot can "see" an image-correlated overlay of the combination of their imaging radar with IR and UV.  It's a black-and-white motion picture of threats, as-if the pilot has "eyes" in the X-band, IR band, and UV band, all at the same time.  The computers backing these sensors also automatically classify imagery targets as potential threats vs friendlies.  A Block IV F-35 pilot will "see" an even higher resolution correlated sensor imagery overlay.  When APG-85 rolls in, they will see very high-definition / very high-frame rate correlated sensor imagery.  This data can then be "shared" with friendly air defense assets, so that the platform which detects the target doesn't also have to fire at the target.  This capability is useful when your jet is out of missiles, but your wingman or a nearby AEGIS-equipped ship is not.

Knowing exactly what your sensors have detected is very important, because it tells you whether or not you're about to shoot down a Tu-160 vs an Airbus passenger jet.

This proposal is all the thrust that a pair of the most powerful fighter jet engines in the world can provide, plus more internal fuel to keep them running than any other tactical fighter in existence, plus more radar imaging detail than anything the Russians or Chinese have in a combat jet.  That seems like a better than average proposition for finding and shooting down enemy bombers.

The downside, of course, will be the operating cost.  Big fancy fighter jets cost big money, so there will be fewer of them.

RobertDyck,

When all you have is an ignorance-based perception of procurement timelines and logistics, every military expenditure looks like an unnecessary extravagance.  When your beliefs about what an enemy will do, when they think they can get away with it, fails to account for their malevolent behavior, the only possible end result is a catastrophe resulting in extreme loss of life and confidence in a government's ability to protect its own people.  The US learned from Pearl Harbor to never be taken by surprise.  After the Cold War ended, that lesson was long since forgotten, yet Russia still existed to re-teach the forgotten lesson.  I don't expect you to understand this, either.

Both America and the European Union, despite both having economies vastly larger than Russia, still cannot match Russia's monthly artillery shell output after 4 years of fighting in Ukraine.  None of the fancy long range supersonic and hypersonic weapons or stealthy cruise missiles have meaningfully altered the course of that war, despite hundreds or thousands fired by both sides.  Drones are a constant battlefield threat to infantry and vehicles, but haven't prevented the current trench warfare stalemate.  Neither side has been able to establish air superiority, so it has not been possible for either side to bring the war to a decisive conclusion.  This is a stark contrast to the first Iraq War, which was over with inside of a month, because one side was able to establish air superiority, which it used to destroy every last piece of Iraqi military equipment more sophisticated than an infantry rifle or anti-tank rocket launcher.

America wasn't even involved in WWII for 4 years.  None of these clown shows masquerading as governments are going to protect your nation from anything.  They operate on wishful thinking and purposeful ignorance of enemy actions.  They lack the intellectual capacity to even comprehend how to respond with any sense of urgency to an actual military attack.  The German Army spent months goofing off with internal travel permits across their own country to transport Leopards to Ukraine.  If you were relying on those people to gear-up for wartime production and to move military equipment expeditiously to where it's required, then your country would look like Ukraine does today long before they'd have their act together.

Do you recall how long it took for European economies to recover from WWII?

Full repair of infrastructure took 20 to 30 years, which means the Cold War was already on the back end before complete recovery took effect.  That's essentially a generation of young working age people who were forced to pay for the "failure of imagination" of their forefathers- people who tried to "wish away" what was so plainly happening in front of their very eyes, in other words people like you.

If you actually believe that, then why is the Canadian defense industry still dithering?

Why hasn't Canadian artillery shell production already surpassed American artillery shell production?

Where is all the action on the part of Canada that backs up you running your mouth non-stop?

In the amount of time that the CF-18 has been in-service with the RCAF, if Canadian Arrow enthusiasts were so hard core about producing an indigenous airframe and engine combination, then why did they not form their own design team to do what Stavatti Aerospace did in America regarding their ideas for A-10 and stealthy trainer replacements / light fighters?

Stavatti SM-31 Stilleto

$23M flyaway cost with the Honeywell F125 engine, $3.4K to $4.4K cost per flight hour.

CF-18s presently cost $15,000 to $20,000 per flight hour.

Canada would not be competing with the US military for design requirements or orders, so Canada could pay for whichever design elements are most suitable for their use cases.

2 squadrons of F-35s would cost the same amount to purchase as 7 squadrons of these Stilleto light fighters.  Canada could field light fighters equipped with Raytheon's Peregrine missiles to take down bomber-sized targets at around 100 miles from the launching interceptor.  It has an internal autocannon, just like all other USAF fighters, and Sidewinders can be fitted to wingtip rails.  Airframe shaping features reduce RCS the most, so Canada could opt for shaping only, without any eye-wateringly expensive RAM coatings to continuously maintain, as would be the case for the F-22 and F-35.

RobertDyck,

I realize the nuance will be lost on you, but the quiet part nobody is saying out loud is that Maduro was acting as an enabler for Russian and Chinese forces, primarily China, seeking to use our backyard as a staging ground for attacks against the US.  China is the real reason America made such a show of force over the Maduro situation.  If you didn't already know this, that's because you weren't paying attention.  Stop taking every politically-motivated thing you read in the news at face value.

Talk is cheap.  Canada never built an aircraft carrier.  The largest surface combatant ever built in Canada, as opposed to being operated by Canada, is their new River class destroyer, at 7,950t full load.  Those ships use Lockheed-Martin's Aegis Combat System, SPY-7 radars, Standard Missiles, and Tomahawks.  They also include propulsive motors built by GE and ASW helicopters built by Sikorsky.

RobertDyck,

The basis for your conclusion is not connected to plainly observable reality.  Canada hasn't taken any concrete actions to counter the threats posed by modern air defense systems and tactical fighters with survivable solutions.  Canada's fighter fleet received its last major upgrades 20 years ago.  Call that whatever you like.

If Canada had simply been "gifted" F-22s, your Air Force would go bankrupt trying to maintain them.  You incessantly complain about the cost of the F-35 without acknowledging the F-22's much higher costs per flight hour.  F-22s are dramatically more expensive to operate, in comparison to any other fighter jet in existence.  You also refused to acknowledge that the F-35 outperformed the Gripen, Rafale, and Typhoon in actual mission performance, according to your own government.  There are more F-35s which have actually been produced to date than all Gripens, Rafales, and Typhoons combined.  F-35s are both less expensive and more capable than the rest of those jets.

The F-35 is better than a Super Hornet in terms of acceleration when it comes to regaining energy lost to maneuvering, it turns better than the F-16 unless said F-16 is unarmed, and it points the nose better than any F-16 during high-AoA maneuvering thanks to those barn door tail fins that are as large as the wings are on some of those other fighters.  Kinematically, for people who still think about fighter capabilities in such terms, the F-35 is every bit as good as those earlier generations of jets when both jets are equally loaded.  A Rafale pilot even said that his latest and greatest copy was, at best, "evenly matched" in a dogfight with his F-35 opponent.  The F-35 does all of that with a stealth-optimized airframe.  None of those other fighter jets have stealth or electronic warfare capabilities in the same class as the F-35.

On top of all that, the F-35 will fly farther on internal fuel alone than anything except a Su-35, Su-57, or F-15EX.  The F-22, F-15E, and J-20 all fall short, especially against the C model.  If the F-35 receives its scheduled engine upgrades, then it will exceed the unrefueled range of everything except a Su-35 in what is essentially a ferry flight configuration, and no Su-35 that heavily laden with fuel will still turn like the F-35.  Whether burner is engaged or not, the drag rise associated with supersonic flight means jets with "supercruise" capability are burning significantly more fuel to do it, period.  In a tactical fighter sized airframe, supercruising is an altogether rather pointless capability if you intend to patrol far from your base and still make it home without on-station aerial refueling assets.  Aerodynamic drag vs Mach number and basic fuel burn rate math is what it is.  Take that argument up with nature.  Let us know if you figure out how to overturn basic flight physics.

Lastly, no other tactical fighter provides F-35 equivalent situational awareness and sensor fusion.  When the APG-85 radar is installed in the upcoming blocks, it will also greatly exceed the detection and tracking capabilities of the F-22's APG-77.  At that point, the F-22, Su-57, and possibly the J-20 with upgraded engines have a slight kinematic performance advantage in a dogfight, but that's about it.  The latest F-35 radar and electronics are 20 years newer than those installed into the F-22.  For a jet that supposedly doesn't do anything well, all those other fighters seem to have a very tough time matching its mix of capabilities.

Imitation is the most sincere form of flattery.  Every new tactical fighter being developed looks like a F-22 or F-35 or one of the various airframe derivatives proposed by our defense contractor primes long ago, but never pursued.  There's probably a reason for that beyond the trite and very tiresome "everyone but me is dumb" explanation.  Either all aerospace defense contractors across all major world powers don't know what they're doing when they're designing F-35 clones, or they know exactly why they opted for their design decisions because they know what right looks like, even if someone like you doesn't.

If you're never going to join the 21st century by fielding modern tactical fighters, then your aviation fleet is relegated to a purely defensive role that (hopefully) never encounters modern air defense systems or other modern tactical fighters.

RobertDyck,

You know how I can tell who's serious about defending their homeland and who's merely paying lip service to the idea?

Actions.  Actions speak louder than words ever will.

Dithering is an action, but not one the enemy respects.

If Canada was truly concerned about fending off a Russian sneak attack over the pole, they'd have enough radars up there so that if a Russian farted in Nagurskoye or Kotelny Island or Rogachevo, Canada would know about it.  I've never heard you so much as mention those names before, which tells me most of what I need to know about how seriously you take the problem.

Since complaining about what President Trump said won't make those air bases disappear, I fail to see the point.

RobertDyck,

Are you unable to acknowledge that the Gripen is just as dependent upon American military equipment as the F-35 is?

Can a Gripen fly without its US-supplied F414 engine?

If not, then it's as irrelevant to this discussion about your personal fears about President Trump as the F-35 is, assuming Canada is truly worried that the US won't supply defense articles to them.

The topic of this thread is selecting a new tactical fighter that serves Canadians military requirements.  To that end, I've put forward some ideas that have at least some chance of helping Canada establish an indigenous tactical fighter development and production.

Are you able to set aside your personal feelings about President Trump so we can discuss more important subject matter?

If not, then what alternative non-US-origin engine will power Canadian Gripens?

What non-US-origin avionics will Canadian Gripens use?

What non-US-origin weapons will Canadian Gripens use?

Back here on Earth, in admittedly less extreme temperatures, for Canadian mining and rock crushing equipment operating in -30C temperatures, they're using a combination of high-Manganese steel, high-Chromium "white" Iron, and Austenitic Ductile Iron.  Mangalloy is the traditional cold weather steel that becomes work hardened with use, but has already been replaced with Ductile Iron in many applications for cost and wear benefits.  White Iron is used in applications where abrasion / cutting from rock is the most important factor, such as razor sharp little shards of crushed rock being pulverized into a powder.  The first couple of stages of rock crushers will be Ductile Iron, with the final one to two stages being White Iron because softer metals will get abraded too quickly.  Chromium makes White Iron very hard.

Nearly every component in a heavy duty diesel engine can be and in fact are made from ADI, with only the connecting rods, pistons, piston pins, fasteners, and other small parts being steel vs Ductile Iron.  Forged 4340 steel is still the best general purpose material for crankshafts and connecting rods subjected to severe stresses, but even high performance engines like Chrysler's Gen III Hemi are now using ADI camshafts as OEM equipment, and some engines use ADI crankshafts as well.  Ford put ADI on the map during the 1980s when they put ADI crankshafts in some of their high-output engines, so one could say ADI is a 1980s and beyond material.  TVR, a British company known for their extreme performance road-legal race cars, was also well known for using ADI instead of forged steel in their high-output V8 and I6 engines.  If ADI lacked performance relative to 4340, then TVR would've discovered this during testing.  OEMs like Caterpillar don't try to "hot rod" their engines though, so ADI crankshafts work for them in their largest mining truck and marine engines, saving piles of cash over modestly stronger forgings.

If you do everything absolutely correctly with a 4340 forging, then you get about 20% more "power holding" capability and fatigue life over ADI, at extreme cost.  Modern "wonder materials" like 300M or Titanium also come with use case limitations, like "don't ever scratch the surface or drop the part on something hard".  You should not expect the average mechanic to abide by those limitations.  You see 300M and Titanium used in race engine connecting rods or aircraft landing gear / wing spars / engine mounts only.  Nobody uses Titanium in crankshafts, which should tell you something.  You would never design a factory diesel engine to use Titanium parts, for example.  You also "give up" toughness at low temperatures and chemical exposure resistance, hence why you don't see Titanium or super alloys used in ship hulls or propellers.  The Soviets used Titanium successfully in a literal handful of submarines, but not without a lot more hull maintenance, and every class of attack sub designed thereafter switched back to steel.  Titanium exhaust manifolds are notorious for cracking.  Everyone with a lick of sense uses stainless, an Inconel super alloy to reduce weight and achieve high temperature resistance, or plain old cast ductile Iron if cost matters at all.  Titanium is pretty and produces unique "engine noises", but engineers with design latitude will generally opt for any other material.

Why ADI for heavy duty earth moving equipment?

ADI is 50% less energy-intensive to make than cast steel and 80% less energy-intensive than forged steel because there are fewer processing steps involving extreme heating.  ADI will give you 80% of the performance of a 4340 forging in a practical application, like a crankshaft.  Nobody makes a crane boom out of 4340 forgings, though.  They all use mild steel or boiler plate steel.  ADI in automotive use is a 120ksi YS material, tempered 4340 can go up to 200ksi if you don't care about toughness, but 125ksi YS is typical of normalized 4340.  Fatigue resistance is better with 4340 forgings only if you spare no expense in production.  Any lesser forged steel is probably not as good as ADI, such as the micro-alloyed low-alloy content forgings that come out of the major automotive OEMs, particularly for crankshafts / camshafts / connecting rods.  They use forging of cheaper steels for part-to-part consistency, not absolute strength and fatigue life.  As heat treatment process control improved dramatically with computerized ovens, appropriately tempered Iron castings largely replaced forgings.

ADI can technically be welded, but isn't worth the expense.  If you want to economically weld parts together, then you really need to use mild steel or boiler plate steels.  The only kinds of cryogenic capable steel we have for heavy earth moving equipment are either 300 series stainless steels, which are no stronger than mild Carbon steels and often modestly weaker, or stronger high-Manganese steels more akin to HY80 equivalents used in ship building.

Caterpillar really likes to use ADI for cast components used to reduce component count and assembly time, or mild steel requiring no special weld prep, so that if someone welds on their equipment or bends a frame rail back into place, the structural integrity of the equipment hasn't been compromised.  Mild steel cannot remain ductile due to the cold temperatures on Mars, which leaves stainless, which is also safe to weld without concern over strength loss.

That complex part on the back of their haul trucks where the wheels / final drive / frame rails attach is a very large single piece ADI casting.  The bucket, cab, and forward chassis components are welded mild steel.  On Mars that would be welded stainless steel.

So, I have a proposal:
Let's "get real" about something fundamental to "civilization building":
Modern human society is built on water processing ability, industrialized farming, thermal energy, steel, and concrete.  All other "nice to have" materials and other technological advancements have come from that foundation.

Every Starship that lands eventually becomes part of the chassis or crane boom or other large components for these mining vehicles that we need to mine enough metal ore to create pressurized habitation to actually live on Mars permanently.  The first order of business is to be able to produce pure Iron using electrolytic reduction techniques.  This requires a lot of electricity, but the temperatures are very modest.  Pure Iron plus small quantities of alloying metals and Carbon unlocks ADI.  Most structural parts can be built using this material, because ADI has few problems with mildly cryogenic temperatures.  As we make more equipment from scratch using mined metals, we'll want to add a steel mill and forging tools so small parts that really need to be forged steel can also be locally sourced.  The only kinds of steels we can expect to survive the Martian nights are ADI, stainless, and high-Manganese alloys.  Every bit of metals-based infrastructure needs to "natively" survive being cold-soaked, meaning the intrinsic material properties are suitable for use in a mildly cryogenic environment.

Most Iron-based alloys used on Earth are intended for construction, with equipment of any kind being a distant secondary consumer of metals.  The majority of Iron production must be directed at pressurized habitation construction, not equipment or vehicles.  Iron wiring is not lightweight compared to Copper or Aluminum, but most of it won't go anywhere after installation, won't corrode, and won't be transported very far, either.  If a length of Copper conductor wire weighed 1lb, then its equivalent Iron wire only weighs 5lbs on Earth, but only 1.9lbs on Mars.  This is obviously not ideal, but eliminates the immediate need for a Copper or Aluminum mining and refining industry.  We can live with that result, though, even if Copper and Aluminum mining takes several additional decades of settlement development before it can be pursued.

After we have re-mastered Iron and steel suitable for production and use in the new context of the Martian surface environment, Aluminum, Silicon, Copper, and Uranium are our next priorities.  Unfortunately, all of these technology metals are also very energy-intensive, which is why they're secondary priorities.

Everything else is an artifact of mass production of those metals.  Iron is the key metal, as it always has been.  When you have Iron, you can make most of the the structures and machines humans need to survive on Mars.  The stainless steel is already being imported from Earth in the form of vehicles suitable for making the trip from Earth to Mars.  If SpaceX follows their plan to deliver 1,000 Starships per launch opportunity, then that's about 100,000t of steel to work with.  Mining haul trucks like the Caterpillar 797 weigh about 215t, so a decently-sized mining operation may have 10,000t of equipment, leaving the other 90,000t available for initial pressurized habitation construction.

We need tracked all-terrain earth movers powered by SCO2 gas turbine engines and electric motors to eliminate gear boxes, drive shafts, and as much of the working fluids as is practical.  The fuel will be a finely powdered Carbon fluidized with CO2 for pumping, compressed O2 or LOX for oxidizer.  The electric motors will save wear and tear on the brakes by mostly not requiring them.  A super capacitor bank will provide the jolt of energy to overcome initial rolling resistance to get the vehicle moving, and then be recharged by the traction motors during braking.  This is essentially an advanced turbine-electric locomotive power train.  Daily maintenance tasks will include fuel replenishment, checking hydraulic fluid levels, track tension adjustment, determining if someone accidentally bent one of the soft stainless steel structural members holding the vehicle together.  When turbine power is not being demanded to propel the vehicle, an electric pump will siphon CO2 from the atmosphere.  At the end of each shift, the LCO2 tanks will be emptied back at the shop where it will be used to supply CO2 for shop air tools and making fresh batches of powdered Carbon fuel and O2 oxidizer using Gallium-Indium-Copper liquid metal.  If we happen to discover a natural gas well nearby, then we might consider using Methane instead of synthetic coal, provided that the rockets don't consume all of the Methane.  Regardless, the Martian atmosphere is the fuel / oxidizer and working fluid of choice.

Since we cannot readily use gigantic rubber tires in a cryogenic environment, we'll use steel track links instead.  The dramatic reduction in relative vehicle gross weight means we need less power, even with tracks vs tires.  The Cat 797F haul truck's gross weight with 400t max payload is 623.7t on Earth, but only 237t on Mars.  Top speed is officially 65kmh when fully loaded, though I would surmise speed depends greatly upon local terrain and room to maneuver.  Instead of 4,000hp, we can manage with less than that, say 1,520hp.  1,500hp corresponds with the output of the M1 Abrams AGT-1500 conventional gas turbine.  Fuel consumption over an 18 hour shift is about 75gph.

US EIA rates diesel fuel at 138,500btu/gallon, so 75 gallons is 10,387,500BTU.

Net electrical output vs fuel burn for the big Cat C175-20 diesel engine which powers the 797F are as follows:
Max rated electrical output is 3.2MWe in an electric generator application.
It's burning 208gph at full output, so 28,808,000BTU.
10,918,400BTU (net electrical output) / 28,808,000BTU/hr (fuel consumption) = 37.9% overall thermal efficiency
Let's be very generous to the Cat engine and assert it's 40% thermally efficient at reduced engine load.

10,387,500BTU * 0.4 = 4,155,000BTU
4,155,000BTU / 2,545BTU/hr = 1,633hp

An average of 1,633hp constant power output on Earth equates to 620hp on Mars.

For a 50% thermally efficient SCO2 gas turbine, 620 * 2 * 2545 = 3,155,800BTU/hr
Pure Carbon produces 14,100 to 14,600BTU/lb, so let's use 14,100.
3,155,800BTU / 14,100BTU/lb = 223.8lbs of pure carbon per hour
223.8lbs of pure C * 2.67lbs of pure O2 per lb of pure C = 597.5lbs of pure O2 per hour
18 hour shifts would therefore require 4,028lbs of pure Carbon and 10,756lbs of pure O2
At 700bar, 10,756lbs of pure O2 would required 12.195m^3 of tank capacity
Pure Carbon powder is 1,800-2,200kg/m^3, so approximately 1.015m^3 of fuel tank capacity

5X 1mDx3mL O2 tanks will easily fit within the engine bay previously occupied by the C175-20, as will the fuel tank and SCO2 turbine and electric generator, although maybe the fuel tank should be in its standard location for what should be obvious reasons.

Anyway, we just did enough simple math to figure out that all the oxidizer and fuel will fit inside the engine compartment with lots of room to spare for the SCO2 gas turbine and electric generator.  The haul truck doesn't require a complete redesign, it only needs to be gutted internally and the best layout for the new power train equipment established.  Therefore, a Caterpillar 797F mining haul truck can be fabricated primarily from 300 series stainless cannibalized from Starships vs mild steel and ADI (already used in Earth-bound 797Fs).  It can then be operated in a Martian metals mining operation with concessions made to use of a more thermally efficient SCO2 gas turbine engine driving an all-electric power train and delivering the power to ADI or high-Manganese forged steel tracks vs giant rubber tires.  It's not perfectly ideal, but nothing ever is.

Note to self:
Make sure the high temperature radiator surface area can be a simple forward-facing steel panel.

Now back to ground pressure and power consumption, and rolling resistance for tracked vs wheeled vehicles...
US Army Published a Table Regarding Generally Observed Coefficient of Rolling Resistance vs Surface Type:
Concrete / Hard Soil / Sand
Heavy Truck: 0.012 / 0.06 / 0.25
Tracked Vehicle: 0.038 / 0.045 / (no value provided for sand in this table)

By the time you move the wheeled vehicle over hard soil, the tracked vehicle already has lower rolling resistance.  If you have to move the vehicle through soft sand, then the wheeled vehicle is all but guaranteed to consume more fuel at equal weight.  Wheels almost always deliver more speed in both on-road and off-road environments with sufficient power available / appropriate gearing, but not for equal fuel burn at equal vehicle gross weight.  If you have a concrete or asphalt or hard rock quarry road, then the tracked vehicle is all but guaranteed to be less efficient.  This follows reports I've seen regarding the actual fuel economy of our wheeled Stryker APCs, which while very fast and fuel efficient on roads, suddenly become fair to terrible in the deep sand drifts of Iraq and loose gravel mountain roads of Afghanistan.

Rubber Tracks vs Steel Tracks:

Go to Page 29 to see the observed rolling resistance coefficients table I referenced above:
US Army Engineer Research and Development Center - Geotechnical and Structures Laboratory - Standard for Ground Vehicle Mobility - February 2005

National Academies of Sciences - Engineering - Review of the 21st Century Truck Partnership: Third Report (2015) - Vehicle Power Demands

The mining haul truck is one of the largest pieces of equipment that needs to fit inside the garage, so 7.75m minimum height, preferably 16m high so the bucket can be tested inside the garage.  The 797F is 9.5m wide, so perhaps the garage should be 25m in width to accommodate a pair of trucks.  Overall length is 15m, so the garage should be 30m long.

Minimum Equipment Garage Dimensions for a pair of trucks, with room to spare for equipment and mechanics:
16mH x 25mW x 30mL