New Mars Forums

SpaceNut,

Maybe we are better off using impermeable fabric and regolith bags only.  There's no significant upper limit to the size of inflatable structures here on Earth.

Take note of the size of the human standing to the left of this structure:

Look at how tiny the cranes are next to this inflatable:

If we can pressurize and fill with regolith dust for structural support and radiation protection, then the habitat should still be there a century from now.  That ought to provide sufficient time for Iron mining and smelting for steel construction.

In the waning days of WWII, the Hütter Hü-211 design was created for high altitude recon and night fighting:

We no longer distinguish between day and night fighters, as virtually all military aircraft are all-weather capable due to advances in radar / radio / avionics, but this design could be a suitable successor to Grumman's S-2 Tracker.  The primary use case for this aircraft is hunting the diesel-electric submarines of adversary nations, which still remain more numerous than nuclear powered attack submarines, and potentially quite lethal since all nuclear attack submarines are not as quiet as diesel-electric boats.

Lockheed's S-3 Viking was capable of a top speed at sea level of 493mph and cruising speed of 400mph, whereas a design such as the Hu-211 would only be capable of about 400mph at sea level with a 300mph economical cruising speed.  That said, the Hu211's max range was modestly greater than the S-3, and endurance is what counts for sub hunting.  Service ceiling for the Hu-211 design was significantly greater than that of the S-2 or S-3, not that high altitude capability matters much for sub and ship hunting.  The Hu-211 wings and butterfly tail were to be constructed from wood for improved performance through reduced weight.  This WWII design was also equipped with early ejection seats and a pressurized cockpit to enable high altitude operations, features now common on turbine powered aircraft.

In modern times, US aircraft carriers are deploying with far fewer aircraft because the Navy cannot afford to purchase and operate as many multi-role airframes as the single-role airframes they replaced.  Aircraft carriers from the Forrestal / Enterprise / Kitty Hawk / Nimitz / Ford classes were designed to operate with up to 90 large aircraft aboard, but due to budgetary constraints and aging airframe maintenance-related unavailability, they now routinely operate with as few as 48 combat jets.  At any given time half of those jets are down for maintenance while underway and perhaps 1 out 4 are fully mission capable.  Irrespective of how individually capable they may be, the loss of numbers of airframes has greatly diminished the aircraft carrier battlegroup's striking power.

Executing an "Alpha Strike", wherein all mission capable aircraft aboard an aircraft carrier are launched in rapid succession to attack a target, a common naval aviation tactic from WWII through to the end of the Cold War era, is now virtually impossible with today's Carrier Air Wing complement and airframe availability rates.  Sustainable sortie rates per carrier some 25 years ago, when I was still part of an Air Wing in Seventh Fleet, fell between 90 and 120 sorties per day, as-evidenced by the past 2 wars where aircraft carriers were extensively used due to issues with basing of land-based aviation assets close enough to their targets to be practical additions to strike packages.  During Operation Enduring Freedom, which our carrier battlegroup deployed to support immediately after 9/11, our Air Wing had at least 60 combat jets to work with.  During the critical initial phase of that war, naval aviation contributed the majority of all sorties generated.

Fast forward to today, and I've heard of recent deployments with as few as 36 jets, because the rest of the airframes were indefinitely grounded while awaiting replacement of timed-out major structures such as wing boxes, wings, and fuselage components subjected to the merciless pounding of landing on and taking off from a carrier.  Concentrating so much money and capability into so few airframes has made each one a precious and irreplaceable asset, which can still only be in one place at one time.  Fully mission capable rates have steadily deteriorated over time, rather than improved, despite the fact that squadron head count has not decreased.  This is a natural consequence of over-working too few airframes.  3X squadrons of 12 F/A-18E/Fs and 1 squadron of only 4 EA-18Gs is not enough planes for an Alpha Strike against a well-defended target.

If we're not actually fighting a war against a peer level adversary like China, then the greatly reduced total number of combat jets may be sufficient to contend with the limited military forces of third world dictators, but that is not the stated military purpose behind maintaining a dozen aircraft carriers and almost as many air wings.  We either have deployable naval aviation assets with fully mission capable rates over 50%, or we don't have a realistic carrier strike force.

P-3s and P-8s are primarily intended to shadow enemy fleet activities and submarines from significant standoff distances, particularly ballistic and cruise missile carrying submarines.  While they also have significant attack capabilities, they were never intended to be front line attack jets, because they're essentially converted airliners with sensors and armaments.  Using them against an enemy with real air defense capabilities would only result in their loss.  The EP-3E Aries forced to land on Hainan by Chinese fighter jets is a good example of this.  The Lockheed S-3 Vikings, earlier Grumman S-2 Trackers, and late WWII to early Cold War Grumman AF Guardians provided organic long range anti-submarine and anti-ship tracking and attack capabilities to aircraft carrier battlegroups.  Whereas tactical fighters like the Super Hornet, or earlier purpose-built attack jets like the Intruder, would nominally attempt to attack enemy ships from higher altitudes and air speeds, Trackers and Vikings were intended to fly much lower and slower, using the radar horizon as a mask against enemy ships equipped with integrated air defense systems.  Regardless of which flight path was selected, all attacks use subsonic anti-ship cruise missiles with significant standoff range to place the launching aircraft well outside the engagement envelope of the targeted ship's air defense missiles.  The speed of the launching aircraft isn't much of a factor, and helicopters using offboard target tracking to send mid-course guidance updates to the missile have successfully attacked ships this way using smaller cruise missiles.

While it's true that supersonic anti-ship cruise missiles and hypersonic ballistic missiles can achieve much higher flight speeds, it's equally true that none of them, except nuclear warheads, are still hypersonic when they arrive at the target ship and existing air defense weapons seem to have little issue shooting them down because their heat and radar signatures make them very visible targets that cannot be confused with airliners or other non-military aircraft.  The tradeoffs associated with using these higher flight speed / altitude weapons is that they either carry much smaller warheads or are substantially larger / heavier / more costly.  The range or potential range of any such weapon is always limited by the ability to provide timely offboard mid-course guidance updates to the missile.  If your giant shore-launched hypersonic glide missile can hit a target at 2,500km away but your shore-based radars can only track ships out to 250km, then you're not targeting anything father away and all that potential capability is wasted.

The anti-submarine helicopters attached to most surface combatants these days can be thought of as short range purely defensive anti-submarine air assets with extremely limited attack capability.  They can launch one torpedo or small anti-ship cruise missile and can only scan the immediate area around the ship they're attached to, because fuel burn is so high that they lack the range to venture farther away.  When these helicopters are down for maintenance, which is most of the time, the ship has no standoff anti-submarine capability at all, certainly nothing akin to the "waypoint ahead" route-clearing capability fixed wing anti-submarine aircraft provided to carrier battelgroups during the Cold War era.

The loss of this critical capability has been widely acknowledged as a serious deficiency by the US Navy, but nothing effective has been done to replace the Vikings because all available funding has been soaked up attempting to build new ships and to maintain the aircraft carrier's now-diminished strike capability.  Worse than that, several drone programs also failed to produce a like-kind capability.

Converting all aircraft to turbine engines and driving up the max takeoff weight of individual combat jets to something in the same ballpark as a WWII strategic bomber has resulted in airframes and engines too expensive and complex to maintain in a practical way, in numbers that would affect the outcome of a war against a peer level adversary.  That process took an entire human lifetime to achieve, helped along by a lot of questionable ship and aircraft projects that resulted in no usable combat hardware, but it's already happened.  The loss of critical mission skills maintenance, since nobody is specifically training to hunt for and attack submarines, is an even greater hurdle to overcome.  When you can only afford to provide perhaps 200 flight hours per aircrew per year, you cannot train your crews to fully develop their ability to successfully locate and attack elusive or well-defended targets.

Flying at 300mph (5 miles per minute) vs 400mph (6.66 miles per minute) vs 500mph (8.33 miles per minute) vs 600mph (10 miles per minute) is irrelevant to hunting for ships and submarines that top out around 0.5 miles per minute.  Your attack aircraft require extreme range and endurance, not extreme flight speeds, because the target has no ability to escape and it's not evading modern sensors.  Even the so-called "stealthy" ships show up quite well on radar and all ships are unmistakable IR targets.  What would be relevant to the mission is being able to affordably launch an entire squadron of planes with a collective fuel burn rate approximately equal to a single tactical fighter.  If you can put an entire squadron of planes in the air for every tactical fighter jet you can realistically operate, mere presence dictates how fast enemy ships and subs are found, as well as the intensity of a subsequent attack directed against them.

Where should your air defenses be directed if a carrier equipped with dozens of piston engine aircraft can attack an opposing battlegroup from a half dozen different angles at the same time?

That is the problem sheer numbers confers to an opposing naval air wing operating a strictly limited number of large / expensive / thirsty tactical fighter jets.  They can and probably will shoot down some of your slower planes, but since they also have nowhere to land following a successful attack, their ability to do that more than once is very limited.  By operating far greater numbers of planes, your own air wing can absorb inevitable combat losses, whereas they cannot.  The tit-for-tat paradigm is broken, so they can no longer rely on superior speed or technology to prevent their destruction.  They're forced to either redirect some funding to lower tier systems or risk complete loss at nominal cost to their enemy.  As always, the radar finds the targets and a torpedo or anti-ship cruise missile does the killing, not the plane itself.

4 fully mission capable Super Hornets equipped with 4 Harpoons per jet is 16 total chances to successfully attack a ship.  Nobody in the squadron is likely to recall the last time anyone carried a Harpoon or trained to attack ships, but it is at least possible to do so.  12 fully mission capable propeller driven planes only carrying 2 Harpoons per plane is 24 total chances to attack a ship.  If you lose 4 planes attacking a ship or they turn back due to engine or avionics issues, then you still have the same number of weapons available as all 4 Super Hornets.  If you lose 1 Super Hornet during an attack, then a quarter of your striking power is gone and likely won't be replaced any time soon.  If you're fighting a naval power equipped with twice as many ships as the US Navy, protected by an extensive array of air defense systems, then attrition is going to happen regardless of how capable your tactical fighter jets are.  The only question is whether or not you can afford that attrition, or not.  We know what the answer is at the present time, which is why we need to alter our thinking about what is required vs what is nice to have if it doesn't come at an unaffordable cost in terms of dollars and maintenance to maintain a necessary combat capability.

I don't believe jet powered combat drones are the correct answer, either.  Thus far, all programs initiated have failed to produce a maintainable solution at a price point below crewed combat jets and helicopters, which is why each new combat drone program is either cancelled outright or drastically curtailed after it fails to deliver promised results.  Drones may provide other advantages related to very specific capabilities, but not without spending a lot more money.  Airframe capabilities are forever tied to max takeoff weights.  In a permissive environment devoid of integrated air defense systems and radar-directed AAA, smaller propeller-driven combat drones can reduce the cost of maintaining persistent air cover for ground and sea forces, relative to much larger and more capable tactical fighters, but in such an environment a piston engine aircraft would also be a perfectly acceptable solution, one which no amount of data link signal jamming can overcome, because a human has direct physical control over the aircraft.  The best AI-enhanced combat drone is still dependent upon interpretation of sensor input and data links to issue requests to the drone to either attack or defend a given target.  That's why the small drones used in Ukraine trail fiber-optic cables behind them.  Nothing in the size and weight class of typical kamikaze drones can overcome the intense signal and sensor jamming those drones are subjected to, and many of them are already as large as a small Cessna.  Nations with more sophisticated jamming suites would only further increase the minimum size and weight of a suitable combat drone to the same class as a tactical fighter equivalent.

I guess we're about to witness exactly how sheer numbers vs technological sophistication plays out if China proceeds to attack Taiwan.  All war game scenarios, without exception, indicate that both sides run out of their high capability cruise / ballistic and air defense missiles in the first month or two of the war, with many scenarios showing both sides completely depleting their missile inventories inside of two weeks.  There will be great loss of aircraft on the ground for both sides, even with multi-layer air defenses.  A smaller-scale glimpse of this was showcased in Israel after they ran out of interceptor missiles and some of the combat drones and cruise / ballistic missiles fired by Iran struck Israeli air bases.  Israeli and American integrated air defense systems and tactical fighter jets shot down approximately 95% of the weapons fired at Israel, and then the remaining 5% proceeded to impact their targets.  If Iran had the weapons inventory to launch even one more such "Alpha Strike" using their missiles and drones, hundreds of weapons would've hit Israeli air bases and air defense systems.

Gun-based air defense systems have made a major comeback for a reason.  There is not enough money or even manufacturing capacity to field enough air defense missiles to intercept the hordes of low cost EO/IR missiles and drones arrayed against them.  The computing power required to reliably guide an EO/IR weapon to a target is far below that of a smart phone, which means it's not very costly to do.  A reliable high power / high resolution / high scan rate radar set for a high speed air defense missile is at least 10X more costly, ignoring the cost of a high power air search and track radar.  That is why US destroyers operating near Yemen resorted to engaging slower missiles and drones using their 20mm CIWS.  They ran perilously short of air defense missiles.  Yemen is very far from a peer level adversary to the US Navy, but the battlegroup we deployed to counter their attacks against Israel and civil shipping in the Persian Gulf resulted in a force that was incapable of more than point defense inside of a couple months.  High capability SM6 air defense missiles were also accidentally fired at a pair of Super Hornets, scoring two blue-on-blue kills, which didn't help matters.  Every mass drone / missile attack in Ukraine results in a few of the weapons finding their targets.  You don't need to be a mathematician to figure out why we cannot continue to concentrate all available defense funding and manufacturing capacity into ever-dwindling numbers of supersonic tactical fighter jets and high capability air defense missiles.

This is only a collection of initial ideas about what a modern piston engine fighter might look like and some basic design characteristics.

ParkFlyer Plastics P-40E Warhawk model flipped upside down:

Attempt to visualize an airframe with shoulder-mounted anhedral wings for improved maneuverability and ground clearance, unlike the model shown above showing with its landing gear on what is actually the bottom of the P-40's low-wing configuration, a mid-mounted supercharged V8 engine, similar to Bell's P39 Airacobra, but with the prop shaft leading to a tail-mounted variable-pitch propeller so that a miniaturized radar can be mounted in its nose like any conventional fighter jet.  Armaments might include a 20-30mm chain gun with 50-150 rounds of ammunition, 4 wing pylons for 4X Peregrine or Hellfire or Griffin missiles, or 4X Mk81 GPS guided bombs, or 4X 7-shot 70mm rocket pods, plus 2X AIM-92 Stinger missiles for self-defense.

WWII era fighters were typically low-wing monoplanes like the P-40, with conventional vs tricycle landing gear, because the heavy main gear could be mounted to the wing's main spar to absorb higher landing loads.  The idea of attaching the gear to a mid-fuselage engine mount was not attempted.  Tractor engine configurations permitted heavy engine / gearbox / propeller / autocannon combinations to be hung off the nose.  Airborne radar was very new back then, so there was little thought given to mounting an air search radar in an ideal location.  Twin engine night fighters did typically mount the radar antenna on or in the nose.  Modern composite materials and aerodynamic drag reduction enables the use of shoulder-mounted cantilever wings.  Stronger and more resilient modern steels enable the use of longer gear legs and tricycle gear configurations without excessive weight penalties.

A modern piston engine fighter should use tricycle gear to prevent ground loops.  Any pusher engine configurations, such as the one I proposed, should always use a tricycle gear configuration to prevent prop strikes.  Pusher engines eliminate prop wash effect over the empennage, which produces a more jet-like control response at low speeds.  This can be viewed as a positive or negative.  If the empennage is appropriately designed, then adequate control authority will be maintained right up to the stall, but the ability to induce a prop strike on takeoff will be greatly reduced.

Mini-IMP In Flight:

Fixed Gear Mini-Imp Variant on the Ground:

Even at 400mph, fixed vs retractable gear, with aerodynamic gear legs and wheel fairings, only results in a nominal speed increase of 5 to 10 knots.

Mini-Imp with Y-Tail and Variable Pitch Propeller:

Air-Cooled General Motors Corvair Mini-IMP Engine and Prop Shaft:

Testing the Mini-Imp, by M. B. "Molt" Taylor

Molt Taylor was an aeronautical engineer who worked for the US Navy during WWII.  IIRC, he designed a drop tank for US Navy fighters operating in the Pacific and worked on weapons separation testing.  He was the only aircraft designer to ever successfully achieve highway certification for a road-legal passenger car that was also a type-certificated light aircraft, and this work was performed during the 1950s, culminating in the so-called "AeroCar".  While the project was technically dragged across the finish line, Taylor's company ran out of funding for series production.  Following WWII, there was a thought process that middle class people living in the US would commute for work over longer distances using light aircraft and then drive said light aircraft's "fuselage" around town.  In a certain sense, this is historically what happened, but the major airline services primarily provided city-to-city transportation using large turbine powered purpose-built hight speed aircraft, rather than slower but less costly owner-operator light aircraft seating 2 to 6 people.  Some 20 years later, the Mini-IMP (Independently Made Plane) was Taylor's 1970s aviation cost reduction project undertaken to create a greatly simplified aircraft that could be made in a garage and required minimal numbers and types of different tools.  Quite a bit of the design process revolved around airframe fabrication simplification.  The "buy vs make" parts of the airframe were simplified to landing gear, engine mount, avionics, and radio.

Prior to designing and building the "Mini-IMP", Molt first designed and built a much larger and more expensive "IMP", similar in size to a modern piston engine fighter type aircraft, using a traditional aircraft engine with construction techniques and materials which were then-common in the aviation industry.  This first pass at the cost and complexity problem was immediately deemed "too expensive / too complex" for a home builder.  It was similar in cost and performance to early RV type aircraft.  Following distribution of the Mini-IMP plans and key components such as landing gear and engine mounts, work on the "Micro-IMP" began, although never completed, which was an even smaller and more affordable plane.  As far as lower cost materials were concerned, Molt also worked on "Taylor Paper-Glass" material, which combined a paper product with glass fiber, intended to be rolled and glued around a mold, similar to what modern fiber tape laying machines do for airliner fuselage and wing skin fabrication, to further reduce construction time and cost.

Anyway, that's the back story on the IMP / Mini-IMP / Micro-IMP and Taylor Paper-Glass...  I never personally met Molt, but I did meet the man who eventually purchased his business and continued to distribute parts and plans after Molt retired and died in the 1990s.  I never asked him about the AeroCar because it wasn't something I was interested in at the time.  The new owner is / was himself a retired airline pilot and someone with a personal love of building light aircraft, and model aircraft as a child.  He and his wife are as old as dust by now, too, if they're still alive.

The cockpit placement ahead of the engine was a deliberate design choice to provide superb visibility in all directions except directly behind the pilot.  Since most other aircraft that might kill you during a mid-air collision are ahead (in front of), above (descending), or below (climbing) you.  Nose-to-tail mid-air collisions do happen, but tend to be rarer.  In any event, as can be seen in the photos, the wing and all other visual obstructions are located aft of the Mini-IMP's cockpit to maximize visibility.  This is also an important design characteristic for all fighter-type aircraft to have.

The Mini-IMP uses NASA's GA(PC)-1 airfoil, which was a member of their "advanced technology" General Aviation (GA) airfoils designed during the 1970s.  This was bleeding edge stuff when Molt included it in his designs.  While they were primarily intended to reduce takeoff and landing speeds for light prop aircraft, they happen to perform decently at higher speeds, approaching the limit of what is legal below the flight levels, because the flaps in many implementations are reflexed upwards to reduce induced drag (from generating lift) at higher speeds.  This is not the type of airfoil that should be used by higher speed fighter type aircraft, though.  Between 75 and 275mph, though, they're pretty efficient.  Back in the day, NASA worked on more projects to benefit GA.  These days, they only seem to do gee-whiz projects for GA, and almost all of that is actually directed at commercial light aircraft, which makes sense in a way.  EAA has pretty much taken over GA innovation where NACA and then NASA left off.  There's no shortage of self-directed improvement projects that EAA members have undertaken, some of which ultimately ended up in the cockpits of commercial airliners.

The laminar flow NACA-66 series used on the P-51 were / are suitable for 200 to 450mph speeds, near-ideal for straight-line cruising, but weren't the greatest for maneuverability.  Spitfires used modified NACA 2200 series airfoils, which provided a good mix of high speed drag reduction and maneuverability.  Focke-Wulf's Ta-152H, a heavily modified variant of their famous FW-190, was ideal for straight-line speed at high altitudes, but again, not so great for maneuverability, nor use at lower altitudes for that matter.  Wing loadings for 400mph sea level top speed fall between 40 and 50lbs/ft^2, which is 1/3 to 1/2 that of a supersonic tactical fighter jet, so takeoff speeds fall modestly below those of light biz jets, meaning 85 to 100mph.  Biz jet takeoff speeds are 115 to 135mph.  Initial climb rates are pretty spectacular for piston engines, meaning 5,000fpm+.  This sort of sea level performance is suitable for turning inside highly maneuverable short-range IR-guided missiles and making aiming difficult for radar-guided autocannon air defense systems.

The Mini-IMP's control surface layout is modestly unconventional, but otherwise unremarkable.  Various empennage arrangements were experimented with, including conventional, cruciform, butterfly, inverted butterfly, Y, and inverted Y.  The inverted butterfly and Y tails were the ones which provided the best compromise between highest cruise speed and control near stall speeds during crosswind landings while making it difficult to deflect the control surfaces to the point of achieving a prop strike on takeoff.  The airfoil chosen was a then-modern NASA design intended to both reduce stall speeds and achieve efficient cruise flight.  Using a 65hp VW engine, the plane could achieve 175mph.  Using the more powerful and ubiquitous 100hp Continental O-200 or 125hp GM Corvair engine, it could hit 200mph to 225mph.  The airframe was relatively light yet strong, rated for aerobatic flight, and control forces remain light at higher speeds.  The cockpit has lots of leg room, or at least the one I sat in did.  The side-mounted control stick near the front of the right arm rest was comfortable to move in all directions.  The ability to see out was much better than any Cessna I've flown, apart from directly behind.  You really can see almost everything.  It was possible to visually confirm that the main gear was down from the cockpit, but not the nose gear.  Airflow into the cockpit in Texas heat?  Not so great compared to the 152s and 172s because the prop is in the tail.  I was baked after latching the canopy.  It does feel like you're sitting on the ground, which you almost are.  Entering was initially awkward, but exiting required no effort at all- open the canopy, stand straight up, and step over.  Entering and exiting a scaled-up model with a V8 engine ought not require a ladder for most average height pilots, stepping on the wing, or other potentially dangerous gymnastics, a bonus for field operations.

Since "flying below the radar" will be necessary for survival of modern piston engine fighters, let's examine operating altitude ranges:

Radar Horizon vs Altitude
10m = 13-15km (8-9 miles)
100m = 40km (25 miles)
1,000m = 130km (80 miles)
10,000m = 400km (250 miles)

Anticipated operating altitudes for modern piston engine fighters should fall between treetop level and 3,000m to reduce or eliminate exposure to long range radar guided missiles associated with integrated air defense systems.  Modern fighter jets fly at higher altitudes because they must, otherwise fuel economy suffers so greatly that combat radius and endurance are unacceptably affected.  Piston engine aircraft can operate at significant altitudes, but a balanced approach to surprise / stealthiness / threat avoidance makes them more effective at lower altitudes where tactical fighter jets guzzle fuel and become more visible targets for shorter-range IR-guided missiles and autocannon fire.

The primary design criteria here are as follows:

1. Much lighter and less costly airframes and engines than turbine powered tactical fighters, with dramatically reduced fuel burn rates and consumption of less expensive gasoline vs kerosene fuel

Airframes fabricated from CNC machined lumber, plywood, and CNF from wood pulp are far less costly than synthetic composites and metals.  Fuselages, wings, wing spars, empennage, and propeller blades will make use of wood and CNF laminate veneers that are pressed and heated to bond multiple layers of material together.  CNC machines can then precisely mill wood parts.  The use of plywood helps assure the average weight and strength of parts using these natural materials.  To the extent practical, synthetic composites and metals won't be used.  Certain fibers such as hemp and flax may be incorporated for specific use cases.  Part of the crash structure for some Formula 1 cars now includes flax natural composites, specifically the seat.  They're still working out how to make the entire survival cage built around the driver out of flax and hemp.  The natural fibers are not as strong as higher grades of Carbon fiber, but other layers of materials such as Kevlar don't need to be bonded-in because natural fibers don't produce razor sharp shards of composite during a crash and do a better job of absorbing impact energy because they actually "crumble", sort of like tempered safety glass, rather than snapping like glass rods.

Amplitex Crash Box:

Amplitex Crash Box Testing:

Amplitex Power Ribs:

The crash box shown above is still about 40% heavier than CFRP, but the seat is 9% lighter than an equivalent CFRP seat and 5X better at vibration dampening to reduce driver fatigue.

Synthetic spider silk is also nearing commercialization, and should be used for cockpit armor to capture shell and missile warhead splinters / fragments.  Rather than some ridiculously expensive and ultimately futile attempt to armor the entire plane, it should instead be used to protect what matters- the aircrew.  Any other use is questionable at best.  The airframes and engines are nominal value expendable assets, as are all other weapons of war.  Gold-plating any solution is counter-productive.  On that note, any weapon system fielded against a competent enemy must be treated as a consumable, so technology must be applied only when it provides a meaningful advantage.  If not, then there's no limit to the justification for sinking more money into any particular weapon or vehicle.  You build to a standard which affords reasonably necessary mission capabilities and crew protection, then use better training, the element of surprise, and superior numbers to win.

2. Cruising speeds 100mph faster than the fastest helicopters and max speeds 200mph faster than the fastest helicopters

Ideal Speed Ranges
150 to 200mph: maximize range and endurance
300 to 350mph: evasive maneuvering
350 to 450mph: swift single passes against well-defended ground targets or engaging airborne targets

Higher flight speeds make more sense only for attacking integrated air defense systems, but all such attacks are executed with Mach 3 to 4 missiles with considerable standoff range.  Autonomous combat drones already act as bait to force air defense system operators and tactical fighters to reveal themselves through defensive missile launches or face destruction.

3. More money is allocated to miniaturized sensors and armaments

Sensors illuminate targets, computers filter noise / clutter / jamming from true signal returns, and precise weapons efficiently dispatch them.  This is where we should concentrate available funding.

4. Repair and complete replacement costs for the airframe and engine are nominal

The ability to lose an aircraft, or an entire squadron of aircraft, without that loss being unrecoverable, is a highly relevant advantage of turbine powered tactical fighters.  If both Britain and Germany were only able to field a few squadrons of fighter jets, even if they did considerably more damage, the air war would've been over for both sides following the outcomes of singular daily battles.

5. Maneuverability is equal to or better than turbine powered tactical fighters

200 to 300mph of increased practical speed, at most, is utterly irrelevant to an inbound missile moving at Mach 2.5 to 4.  We've already discussed why nobody flies faster than Mach 1.5 in air combat.  Any speed over Mach 0.95 consumes fuel so fast as to be highly impractical in all but the most narrowly defined engagement scenarios, nearly all of them at high altitudes, even though it's technically possible to achieve using turbofan and turbojet engines.  F-111s could and did fly at Mach 1.2 at treetop level, not using a phenomenal thrust-to-weight ratio typical of modern tactical fighters, only optimized aerodynamics in that speed range.  Unfortunately, using this tactic rendered them highly vulnerable to air defense missile battery fire during the Viet Nam War, so several were lost to controlled flight into terrain attempting to evade missiles, a clear indicator of their inability to perform effective evasive maneuvers at such high flight speeds, despite a 7g maneuvering limit and generally excellent maneuverability.

Flying at high subsonic speeds near the ground to evade longer range radar tracking from integrated air defense systems precludes tight turns necessary for terrain and missile avoidance.  Rapid downward altitude changes to capitalize on terrain masking to break radar locks are not possible.  Rapid upward altitude changes only make the targeted aircraft more visible to threat radars.  Whilst flying at higher altitudes renders both modern tactical fighter jets and WWII era propeller driven bombers functionally invulnerable to man portable IR-guided missiles and medium caliber radar-slaved autocannon air defense systems, they then become ideal targets for faster and potentially more lethal radar guided air defense missiles with significant ranges and powerful warheads.  Stealth technology then made achieving a radar lock against a fighter jet operating at higher altitudes and high subsonic cruising speeds much less likely at extended ranges, but their IR signatures are unmistakable.  If it ever becomes practical to perform volume search using powerful long range electro-optical sensors, then radar stealth becomes far less effective.

Maser-based radars will ultimately render existing radar stealth technologies ineffective.  The stealthy features of the F-22 may reduce the radar return signal strength by 1,000X when compared to a similar non-stealthy airframe, but per unit area a maser also delivers at least 1,000X greater microwave radiation intensity.  Deployment of maser-based air search radars implies that we revert back to using lower altitudes and flight speeds in conjunction with terrain or radar horizon masking to hide from vastly more powerful maser-based air search radars that can still lock-up a stealthy tactical fighter jet almost as easily as non-stealthy jets.  Geometry provides most of the radar signature reduction (deflecting inbound radiation in any direction except directly back at the source emitter), not RAM, which mandates another 3 orders of magnitude in radar return strength reduction to maintain radar signature levels similar to those already achieved by the F-22.  That's likely impossible, so a 0.001m^2 F-22 radar target is about as visible to maser-based air search radars as a 1m^2 radar target is to a conventional X-band air search radar today.  Modern X-band radars can track 1m^2 targets from over 200km away, so existing radar stealth technologies won't sufficiently reduce tracking ranges against maser-based radars to remain militarily useful.

If radar and infrared signature reduction measures can't passively protect our military aircraft, then we must develop and deploy active protection systems to destroy inbound missiles.  Our armored ground combat vehicles already use these technologies.  Sufficiently accurate autocannon turrets should be able to reliably destroy inbound missiles, making the entire stealth vs non-stealth argument irrelevant on cost grounds, irrespective of future application of new radar and electro-optical tech improvements.  Ground-based autocannon systems are already used to intercept inbound artillery shells and missiles.  Using a moderately successful implementation, air defense system operators might expend far more money launching missiles at piston engine bombers flying at 20,000ft and 200mph than the aircraft are intrinsically worth, prior to achieving a kill.  That makes everyone's near total reliance on defensive and offensive missiles an impossible math problem.  We then revert back to using cannons and guided glide bombs to saturate a target area with weapons so that at least one shell or bomb will destroy the target.  Glide bombs dropped 10 miles away keep the launching aircraft outside the engagement envelope of lower cost high powered cannons and shoulder-launched IR-guided missiles.  Nominal cost kamikaze drones already capitalize on this missile math problem, but unmanned combat drones with similar size physical size / weight / payload-to-distance capabilities as crewed tactical fighters cost every bit as much as crewed fighter jets, frequently substantially more than crewed aircraft, which is why the US military has retired so many of their higher tier capability combat drones.  All their supposed cost reductions never materialized.  This was re-proof that airframe cruising speed, therefore engine cost, operating empty weight, therefore materials costs, plus sensor and weapons capabilities, drives procurement and operating costs, not the presence or absence of a crew member aboard the aircraft.

ATK's LW25 lightweight 25mm autocannon:

LW25 Dual-Feed Turret:

LW25 capabilities:
LW25 Integration on SAAB Trackfire RWS

The 68lb LW25 has a dual-feed system, so a single-feed system suitable for aircraft defensive turrets could be as light as the 63.5lb M3 .50 caliber aircraft machine guns used aboard US aircraft since WWII.  LW25 cyclic rates are lower than M3s, but that might not matter as much when using programmable airburst munitions capable of high precision distance-based fusing in conjunction with low-cost / lightweight / short-range (5-25km) / high resolution imaging radars with AI-enhanced control software capable of automatically tracking and engaging inbound missiles.  If the LW25 is insufficient, more powerful higher velocity autocannons are available, such as the M230, at the expensive of weight and cost.  Single barrel chain guns like the M230 cost about $25K per copy, less for the smaller caliber models and more for the larger caliber models, more expensive than M3s but more effective with appropriate munitions and far less costly than Gatling autocannons like the M197 and M61, at $250K per copy.

If autocannons alone prove insufficient for stopping inbound missiles, then Stinger missiles are an alternative, much more costly than cannon shells though much less costly than large radar-guided air intercept missiles.  Fiber lasers will eventually become viable, too.  What likely won't become a more practical option is sinking ever-greater sums of money into individual airframes and engines for 200 to 400mph worth of usable speed difference while facing inbound weapons moving 2 to 4 times faster than a turbine powered tactical fighter can manage without rapidly exhausting its onboard fuel supply.

Oldfart1939,

ULA's so-called "crasher stage" concept landed a RL-10 powered Centaur upper stage on the moon using thrusters affixed to all four corners of the vehicle so that the upper stage could land on its side, which was a very stable landing configuration, relative to a vertical Centaur-based lander similar to the one proposed by Lockheed-Martin, or SpaceX's "more ridiculous" super-sized version.

This 2013 article from Jon Goff, over at Selenian Boondocks, describes his take on the concept:
Centaur UnCrasher Stages for Simplified Lunar Landings

GW,

A larger Starship should be cheaper to fly than a Falcon Heavy.  Falcon 9 / Falcon Heavy are both reliable rockets, and fit-for-purpose, but the marginal cost of flying a mass produced Starship will likely be much lower than the Falcon series because SpaceX is creating the infrastructure for Starship mass production at a scale it never did for Falcon and Dragon.  SpaceX also failed to man-rate Falcon Heavy, which is a problem.  Maybe not a big one, but an impediment nonetheless.  Atlas V had the same problem, which ULA later rectified, but only at extreme expense.  Regardless, fuel costs are going to become significant under this new operating regime of daily or even hourly launches.  A rocket flown that way must burn the cheapest fuel money can buy, and that's Methane.

A Falcon Heavy flight is around $100M and the independent analysis math on a Starship flights says marginal cost is around $10M per flight, and SpaceX could charge between $20M and $100M per flight while undercutting all existing orbital launch vehicles by a considerable margin.

Why launch a crew aboard one marginally capable heavy lift rocket when you can launch 10 super heavy lift rockets for the same price?

A 2,000t mass allocation is a pretty robust mission package, is it not?  You ought to be able to do quite a bit of science with that.

$200M to $1B to deliver 2,000t IMLEO (double the mass of the ISS), for a crewed exploration mission, has to be one of the cheapest exploration missions in living memory.  If they only charged $20M per flight, then the mission can be 10,000t IMLEO for $1B.  Putting a Ford Class aircraft carrier's equivalent tonnage (110,000t) into LEO, costs less than building the actual USS Ford.  I have to believe that Elon Musk and SpaceX understand that all commercial and colonization missions revolve around cost per ton delivered and little else.  If government budgets are restricted in the future, then all future exploration missions will be similarly budget-constrained.  There will still be more than enough dollars for exploration missions.

SpaceX, Blue Origin, and our other aerospace primes should be focusing on creating a "shopping catalog" of mission hardware sets, so that anyone who is willing to foot the bill can select from their catalog and walk out with the hardware required to perform a specific mission.

I agree with the idea about using a space tug, but not one that requires constant refills of cryogenic liquids.  Tugs should be used for slow but inevitable "heavy hauls" of vehicles and cargo to higher orbits using electric propulsion, wherein time spent spiraling-out is a non-issue.  We can afford to use pure chemical propulsion for rapid transit with crew members to GEO.  The radiation fluence at the orbital altitudes involved is nowhere near what it is within the heart of those captured proton belts.  NASA has worked on ZBO tech for a very long time now.  It's either time to get that up and running if we're going to do tugs using cryogenic liquids, or to move on to other more productive propulsion technologies.  If someone gets ZBO to work at a later date, then we'll circle back to it.

RocketStar has developed and flown in space their FireStar aneutronic "fusion afterburner" for electric ion engines.  It improves thrust output by 50%, so nothing too spectacular, but Isp is 7,300s and the primary propellant is water.  All they're doing is ramming high energy protons from the ion engine exhaust into Boron atoms and fomenting a very rapid radioactive decay chain starting with Carbon-12, a serendipitous exploitation of unique atomic properties of Boron and water, that briefly uses fusion as a radioactive decay catalyst, and dumps the heat into water vapor, creating more thrust in the process.  The process is highly electrically efficient, and that is what matters, because it consumes electrical power rather than producing any from fusion.  The extra power doesn't even come from fusion, only the rapid decay of Carbon-12.  Work began back in 2014 from the results of an AFRL propulsion experiment for their spy satellites, IIRC.  The specific phenomenon being exploited was understood and known to occur, but nobody thought to use it to generate additional thrust from an ion engine.  It took RocketStar's people about 10 years from basic concept to working ground engine demonstrator in 2024, followed by an in-space demo in 2025 about a very small 6U Rogue Space Systems commercial micro satellite, named "Barry-2", primarily intended to demo COTS computer hardware in a high radiation environment.  I believe it was launched aboard a Falcon 9 as a tertiary payload, March 15th, 2025, with the satellite's designator being OTP-2.  NORAD ID was 63235.  So far as I know, it's now defunct.

I think a tiny amount of Boron mixed into water is a suitable propellant for in-space propulsion using existing ion engines.  Even gases like Argon or Oxygen or Nitrogen are more difficult to store and costly to obtain in pure form, in comparison to Boron and water.

All the more advanced fission and fusion concepts look very promising for high-thrust applications, but they're also very difficult to do safely and none of them are ready to use in the near term, which means they'll need to be worked into the program over the next 10 to 20 years.  A water propellant 7,300s Isp ion engine with 2,900N of thrust per MWe of input electrical power is a nice consolation prize in lieu of Helicity's "real" Fusion Drive or BWXT's NTR.  As I said before, baby steps.  Fusion catalyzed Carbon-12 radioactive decay is good enough for now.  Learn to accept the consolation prizes and move forward using what we can do over the short term for in-space propulsion.  Real star-like fusion and fission reactors the size of trash cans pumping out a gigawatt of power are just really hard to do properly when they're not national priorities.  We'll eventually make them work the way we want them to, but not in our immediate future.

In the mean time, we can still put together a pretty spectacular exploration class mission using what we have working right now or will have working within the next 5 years.  I think it's reasonable to assume that Starship will be up and running 5 years from now.  5 years of FireStar development would deliver a MW-class pulsed plasma ion engine up and running.  We've already ground tested several MW-class ion engines, and have decades of development work behind them.  We're not working with a completely new technology here.  It's a novel application of existing technologies, but purely operates on existing tech nonetheless.

If we can achieve a direct transfer to a high orbit using a lightly loaded (personnel only) Starship, with no docking or transfer until you get to GEO, isn't that simpler and faster, even though a space tug would still work?

For a chemical space tug, what major part of the upper stage vehicle mass do we get to leave behind?

Won't it be limited to the heat shield only?

SpaceNut,

If leftists want our Police to treat them more humanely, then they should stop chasing them around, throwing things at them, spitting on them, vandalizing their vehicles, threatening to murder them in their sleep, and threatening to murder their families.  Those are not the behaviors of someone who wants "de-escalate" anything.

RobertDyck,

EJ230 for Gripen E

From Reddit user "Live_Menu_7404":

From Reddit User "RobinOldsIsGod":

GE offers an up-rated F414 as well:
GE F414 Enhanced Engine

RobertDyck,

I have a former top NASA official who has a report that says the moon is made of cheese.

ICE agents are sworn federal law enforcement agents.  If you deliberately interfere with their operations, they have the authority to apprehend and arrest you.  You are free to disagree, but I take my legal positions from the US Supreme Court, not Canadian leftists making absurd statements about laws they are clearly ignorant of.

If a criminal has one weapon that you found, they may have other weapons you haven't found.  It's really hard to determine what weapons someone does or doesn't have on their person when they're resisting arrest.

The US Supreme Court disagrees with your personal interpretation of who ICE may apprehend and arrest, or any other law enforcement agency for that matter.

I agree that ICE may not murder anyone, but nobody was murdered.  Shooting someone resisting arrest while using a vehicle as a weapon or carrying a weapon is not considered murder, in much the same way that shooting someone who is trying to shoot you is not considered murder, either.

The US Supreme Court has already issued opinions on these matters.  Your personal beliefs about what the law should be or how our laws should be interpreted are not affirmed by case law precedent.

SpaceNut,

Does US law prohibit foreign nationals from entering the US who are already violent convicted felons in their country of origin?

RobertDyck,

False.  ICE agents are sworn federal law enforcement officers.

Your line of reasoning on this is about as intelligent as stating that a FBI agent can't pull over and arrest a drunk driver because the legal limit for intoxication varies from state-to-state.  They can and they do, when they have to.  Our courts have already ruled on this matter.  Your creative interpretation of what you think should happen doesn't affect what will actually happen to you if ICE vs FBI vs State Trooper pulls you over for DWI.

Yes, you are living in a bubble of disinformation.

I posted a video of Pretti assaulting federal law enforcement officers.

Here it is again since you missed it the first time:
Associated Press -  New video shows Alex Pretti in scuffle with federal officers days before his death

The video footage from The Associated Press is not a lie, it was not made up for sake of argument for or against anything, but it shows Pretti seeking out and assaulting ICE agents, vandalizing their vehicle, and then assaulting them while armed with a handgun.  He repeated that same pattern of violent behavior 11 days later.  I don't care what parts your "protesters" chose to film or not film.  He did the same thing twice and was shot the second time he did it.

One of the two federal law enforcement officers who shot Pretti was first employed in his federal law enforcement role under President Obama.  When President Obama was President, Minnesota's local and state governments and law enforcement agencies were cooperating with the President so that ICE agents didn't need to go door-to-door to arrest and deport people who had already been arrested by local and state law enforcement officers after they committed various violent crimes (rape, robbery, murder) against people living in America.  That is "what changed" when President Trump became President, because Walz (Governor of Minnesota, Democrat) and Frey (Mayor of Minneapolis, Minnesota, Democrat) decided they no longer had to comply with federal laws.

Nobody was asking you to defend President Obama's actions.  I did ask why you said nothing about ICE deporting illegal alien criminals under President Obama.  Your response tells me you don't know what's going on now and didn't know what was going on when President Obama was in office, either.

False.

Arrest and deportation can take place at the local jails or we can send ICE agents door-to-door to find and arrest violent illegal alien criminals after they've been released on bail by local and state law enforcement officers.  The people ICE has been deporting have already had trials, and have already been convicted of multiple violent crimes, which is why they shouldn't have been allowed to infiltrate into America to begin with.  In other words, the criminal behavior of these illegal aliens ICE is arresting did not start or end in America.

I didn't forget where you live, not that you'd ever let anyone forget that you're Canadian.

Since this entire conversation has been about what's going on in America, it should've been obvious that what I said applies to America, where ICE absolutely does have jurisdiction.  You've been to America multiple times, according to you, and since you cannot seem to distinguish between your personal beliefs about our laws and law enforcement vs real application of law enforcement, I was providing instructions related to how to not get yourself killed while interacting with American law enforcement officers.

If I didn't care about what happens to you, then I wouldn't bother with correcting your media-induced misconceptions about our laws.

RobertDyck,

For your own physical well-being and continued existence on this Earth, and specifically because I value your life, if an American Police Officer tells you that you are under arrest, if you are driving a vehicle then stop the vehicle and turn off the engine when they tell you to do so.  Do not physically assault them.  All of your absurdly childish beliefs about what they should do are not going to protect you from the consequences of resisting arrest.  I can and will show you multiple videos on YouTube of criminals who did exactly what Renee Good did, and most of them were shot dead.  A few survived and are now serving lengthy prison sentences.

You're defending the abhorrent behavior of radical leftists who went out of their way to attempt to prevent ICE from arresting child rapists and murderers because you hate President Trump.  In your worldview, you think it's "more moral" to attack and harass law enforcement officers who are upholding the law than it is to stop violent criminals from continuing to prey upon American citizens and other illegal aliens alike, most of whom are leftists.

Ana Kasparian is one of your fellow leftists, a typical Californian hippy-dippy-doo-dah, but after she was raped by an illegal alien, she had a "brain reset" when the only person who demonstrated any care or concern for her well-being was, in point of fact, someone who voted for President Trump.  Since she only discovered this long after he helped her, her anti-logic programming loop was finally "broken" by her inability to "reject reality".  Her brainwashing didn't have the opportunity to paint the man who helped her as "the enemy" because he didn't share his political opinions with her because she never asked him.

If you choose to follow law enforcement officers around while armed, and then proceed to assault them while resisting arrest, the most probable outcome is that they shoot you.  Whether you accept that this is the case or not, I'm telling you it's the most probable outcome.

You have that backwards, my friend.  ICE is being harassed in Minnesota because Republicans won the last election and are once again enforcing our immigration and fraud laws.  As a citizen, there is no absolute right to harass law enforcement officers performing their lawful duties, simply because you disagree with what you think our immigration and fraud laws should be.  The legislature and the courts are the proper places to resolve differences of opinions over our laws, not the streets, and certainly not by seeking out and initiating violent assaults against law enforcement officers.

ICE is actively operating in all States of the Union, not just Minnesota.  There are plenty of ICE agents here in Texas.  I've seen some of them in public.  The only major difference is that here in Texas our local and state governments, whether run by Democrats or Republicans, do not fund and operate local domestic terrorist cells, because they don't tolerate interference with any law enforcement operations, irrespective of the politics involved.  Houston is a Democrat-run city.  Our state's governor is a Republican, but almost all our major cities are run by Democrat politicians, not Republican politicians.  Here in Texas we all seem to agree that we do have laws, they will be enforced, and as always, you are free to leave if you want to live some other place where the laws mean nothing because they are not enforced.

You have repeatedly failed to tell me why ICE wasn't President Obama's "Gestapo", so I will assume that you have no answer to provide.  People who make completely absurd arguments about their indefensible positions never seem to be able to provide such answers.

When President Obama was using Predator drones to launch Hellfire missiles at American citizens who were not even suspected of any crimes, you did not say one word about it.  They were never given the mere opportunity to surrender to law enforcement.  That is what a real government-sponsored murder looks like.  I've pointed this out multiple times and have received radio silence from all leftists on this forum.  That tells me what I need to know about you.  You either think our government can do no wrong when your favored political party is in power, or your application of basic logic is highly inconsistent because it's driven by political beliefs and personal prejudices instead of higher reasoning.

Since there is no consistency to your complaints about America's government whenever Democrats are in power, in the absence of any statements from you, I will assume this is purely related to your prejudiced personal political beliefs and feelings towards President Trump, specifically, and Republicans in general.  I will continue to retort with basic logic, facts, and reasoning.

If you ever begin demonstrating logical consistency by criticizing the exact same actions taken by Democrats, then your words may carry more weight with me.  Until then, you come off as a typical leftist political hack who has no real issue with the same law enforcement actions executed by Democrat-run governments.

Void,

All the concepts I've seen from you seem to involve "floating" the lens on the surface of the water, but I'm talking about suspending the lens above the water so that it's not subject to unintended deformation from wave action.  This is just an idea that may or may not work for any number of reasons, not something I've completely thought through.  It struck my fancy because it's reasonably simple in theory, can be purely mechanical by using mechanical sun trackers, and uses low cost materials for construction.

Edit:
Maybe the correct analogy for the silicone lens, rather than a "breast implant", is actually a multi-cell "air mattress" which contains fresh water.