New Mars Forums

tahanson43206,

Yes, testing can be performed with N2 vs H2.  This is fairly common.  The safety equipment required for using H2 as the test propellant dictates some fairly extreme equipment costs.  Only a well-equipped university labs or NASA ion engine test facilities would have that kind of equipment.  Performance values can be extrapolated.

H2 mass flow rate (mdot) was anticipated to be around 1kg/s.  I think I originally empirically derived H2 flow rates obtained from NERVA documentation.

Target / desired Isp was 1,000s, which is how the 40MWth input figure was derived.

I believe 3,200K corresponds with a 1,000s Isp using H2 as the propellant, NOT the 2,750K I originally used.

Target thrust level was 10 kiloNewtons vs the 1kN I kept referencing.  My memory is not what it used to be.  Apologies.

Thrust = g0 * Isp * mdot
9,806.65N = 9.80665 * 1,000s * 1kg/s

mdot = Thrust / (Isp * g0)
1kg/s = 9,806.65N / (1,000s * 9.80665)

Isp = Ve / g0
1,000s = 9,806.65m/s / 9.80665

That all seems to check out.

We'll use 14,300J/kgK as the Specific Heat Capacity of Hydrogen gas, but the real input energy is here:
NIST - Hydrogen Specific Heat Capacity

14,300J * 3,200K = 45,760,000J/s of input thermal energy

1 Watt = 1 Joule per second

45,760,000J/s = 45,760,000W/hr

45.76MW <- Closer to actual input energy requirement

I think I remember what I initially did wrong.  I miscalculated the temperature required.  I think I used 2,750K or something like that.

14,300J * 2,750K = 39,325,000J/s <-- That was indeed my mistake

So...

45.76MW / 0.95 CoP = 48.168MW <-- This is closer to our true input optical power requirement, after accounting for 5% losses in the optical array.  There will be some additional power losses involved with heating of the core.  We need GW to tell us what those might be.

tahanson43206,

After reading through, I'm genuinely impressed by how much work ChatGPT has enabled you to undertake on this idea I had.  Whatever improvements were made between the answers it provided regarding transporting of shelf-stable chemicals to be converted into rocket fuel, on-orbit, and this work on photonic propulsion, I approve.

tahanson43206,

Unfortunately, I'm very sick right now, so I won't be joining.

RobertDyck,

If China or Russia conducted a sneak attack against Canadian air bases, then they might destroy aircraft sitting on the ground there, or at least immobilize them by cratering the runway they require to takeoff and land, before an effective defense or counter-attack can be mounted.  After Canada's air assets are either destroyed on the ground or otherwise rendered inoperative for lack of a runway to operate them from, even a purely defensive response becomes more difficult.  Did you pay attention to what the Russians did to Ukraine's air bases at the outset of the war?  If the destruction of Ukrainian air bases was not enough of a wake up call, then how about the damage done to Israeli and Iranian air bases?

A stationary air base is not nearly as difficult to attack as a mobile air base.  Air bases remain exactly where they were from the time they were built until the time they're closed, so finding one only requires a small observation satellite or an airborne radar sensor aircraft, which could be located hundreds of miles away if it's at high altitude.  Land based long wavelength over-the-horizon radars possessed by Russia and China can also create target images of our air bases.  You don't need expensive guidance electronics and sophisticated onboard sensors to launch a weapon against a fixed point on the surface of the Earth.  The moment your target is mobile and can be relocated to a different ZIP code inside of 30 minutes, the sophistication of both the target detection / tracking solution and the weapons used to conduct a successful attack goes up exponentially.  To successfully attack an airbase, a ballistic missile or glide bomb using purely inertial guidance is sufficient.  The cost of glide bombs is about equal to 155mm artillery shells.  The ballistic missiles are obviously more expensive, but the speed of the attack is much greater, so there's less time to defend against it.  To attack a carrier battle group, you need cruise missiles with radars or imaging infrared sensors, off-board inertial guidance delivered via jam-resistant data links, and remote airborne or satellite sensors capable of finding and tracking the carrier.  That is far easier said than done.  If you knew a carrier's last position, as of 15 minutes ago, that's not good enough.  If the carrier was moving at only 20 knots, then it's already 5.75 statute miles away from the position where it was last spotted.  The carrier could be anywhere within an 8.625 mile radius if it was moving at 30 knots.

The counter-argument in favor of large air bases is that they can and typically do launch more sorties per day, in comparison to a super carrier.  That is especially true for the US Air Force, but only because they have as many or more aircraft stationed there as can be carried aboard an aircraft carrier, aerial refueling tankers, labor-saving devices for rearming planes which are not present aboard a carrier, a host of other aviation support assets such as ISR and CSAR, and defense-in-depth of said air base, which is largely provided by the Army (Patriot and THAAD) or Navy (the AEGIS Combat System has the ability to guide any weapon from any ship using data links, namely SM3 / SM6 / ESSM / RAM, and the fully integrated electronic warfare suite used to jam or decoy inbound missiles).  This is great for the US Air Force, but the last time they operated in contested air space was the Viet Nam War, and numerous aircraft were destroyed on the ground by surprise artillery barrages.  The runways were also cratered.  They were repaired, but that took time.  Meanwhile, the Navy and other air bases had to provide air support to help repel the attack while repairs were effected.  The air base in question was defended by SAM batteries, but those weapons were useless against incoming artillery shells.  Canadian air bases may be located far enough inland to prevent that kind of simplistic attack from being effective, but that also means they're far enough away that immediate retaliation is not an option.

Fighter aircraft like the Hornet or F-35 are small enough to store in hardened aircraft shelters with their ground support equipment.  I've never seen hardened shelters for aerial refueling aircraft.  B-2s get their own shelters because there's only 20 of them and they're strategic assets.  Maybe Canada could do something similar for their tanker fleet, but will they?  I'm sure more and larger shelters could be built, but at that point we're talking about serious money being sunk into air bases so-equipped.  If SAM batteries and facilities hardening don't grant near-immunity to an attack, that's a serious problem.  The point is, you're never going to get a "cheap but good" solution.  The solution will always be a major compromise so as to be cost-justifiable by your politicians.

At a more fundamental level, do you think Canada has sufficient air power to stop surprise Russian and Chinese attacks (from something as simplistic and low-cost as a mass drone barrage launched from a Russian container ship in response to Canadian support for Ukraine)?

The Israelis and Americans ran out of missiles to intercept the barrage of missiles and drones launched by Iran.  If Iran had the resources of Russia or China, they could launch waves of attacks, as-seen in Ukraine, and then all the previously defended air bases and cities start getting hit because there are no interceptor missiles left.  That has happened numerous times to both the Ukrainians and Russians.  They have an effective defense until the missiles run out, and then the lack of AAA assets means there's not even an effective point-defense to backstop running out of missiles.  In the mass attack launched by Iran, American Eagles scrambled to intercept resorted to firing their cannons after they ran out of Sidewinders and AMRAAMs, which they immediately stopped doing because when the drone or missile warheads detonated from being struck by the 20mm cannon shells, they spread shrapnel in the flight path of the Eagles.  The risk of "shooting yourself down" was too great for that tactic to be effective.

The real lesson to be learned there is that AAA cannons for air bases and ships are not a "dead technology" as a means of effective point defense, because modern radar-guided AAA has been shown to be a viable interception tool when used against comparatively cheap and slower drones and missiles.  The Shahed 136 drone can deliver a 50kg warhead to a distance of about 1,600 miles.  That means anybody with a cargo container ship could feasibly launch hundreds of them at an air base, and some of them will inevitably make it through the missile defenses and fighter patrols.

Asserting that the US will help is to ignore the timeline for an effective response to be mounted.  It takes at least 4 to 6 hours for aircraft to be scrambled in numbers from US air bases, 24 hours for carriers to be deployed from naval bases in CONUS, so the attack is likely to have already destroyed whatever air assets Canada has, before any reinforcements show up.  In short, there's no "magic button" that America can press to fight back if the attack occurs more than a thousand miles from the nearest friendly units.  As such, any allied nation which values its own military had better make sure that they can at least repel an attack long enough for help to arrive.  If we have some inkling that an attack is likely, then of course we'll try to pre-position assets to intercept, but that typically only works against known military assets like Russian Tu-95 bombers and their warships.

If Canada did have carriers, of whatever size Canadian military experts deem most appropriate, and enough of them were built to keep at least 2 deployed at-sea at all times, the timeline for an effective counter-attack is considerably reduced, to the point that the Russians or Chinese are far less assured of being able to effectively "ground" Canadian air assets when they're needed most.  America has so many military assets, spread over such a large area, that the results from a surprise attack doing much more than steeling American resolve to lay waste to the attacker is non-existent.

As 9/11 and Pearl Harbor proved, if you're willing to die for your cause, you absolutely can successfully attack America in a big and highly destructive way, but you should fully expect that any military capabilities you had will be reduced to near-zero afterwards, irrespective of how long that takes or how costly it proves to be.  Despite that simple fact of history, our reaction has never been an effective deterrent against attacking America.

These are the real military capabilities aircraft carriers confer that air bases do not:

1. To generally forego the destructive results of a surprise attack by being mobile and therefore unpredictable
If you had 4 light carriers and all of them were in different physical locations, there's probably not a realistic attack scenario which can disable or destroy all of them at or near the same time.

2. To rapidly strike back against an attacker following a surprise attack
Swiftly "returning the favor" is an under-appreciated aspect of carriers.

3. To support ground maneuver elements without moving the aircraft nearer to the enemy
Enemy troops can walk to an air base, but they can't swim to an aircraft carrier unless it's anchored.  Attacking a carrier battle group in small boats is not a realistic option.  You need your own blue water naval assets if you wish to engage prudently operated aircraft carriers, which use hit-and-run strikes and movement to confound attempts to sink the carrier.  This fixes the "minimum complexity solution" that any potential adversary can effectively employ to neutralize Canadian air power, and that bar is set fairly high.  In the real world, there's never been an effective submarine attack against a carrier.  These fictional "carrier sinking scenarios" always begin with conveniently co-locating the submarine and aircraft carrier.  If the submarine had to move underwater at 20 knots to at least keep pace with a carrier, then it's going to make enough noise to be detectable.  After the ASW helos fix its location, it's probably not going to survive.  There's far more mythology to submarine capabilities than real world equivalence.  However, when operated at low speeds, they make fantastic stealthy first-strike platforms that can do a lot of damage in a hurry.  The majority of ships sunk or seriously damaged since WWII received bomb or missile hits or they struck a mine.  If I had a sizeable fleet of attack submarines, I would use them as the excellent first-strike weapons that they are (against commercial ships or land targets that can't fight back), and only reluctantly attempt to engage carriers with them if no better options were available.  I'd much rather lose an entire squadron of heavy fighters and expend several hundred cruise missiles to successfully attack a carrier, than lose an attack sub in an ill-advised attack wherein multiple ships have the opportunity to sink my sub.

4. To rapidly distribute supplies to friendly forces or humanitarian aid after a natural disaster
The ability of carriers to deliver badly needed consumables, or to medevac any injured or wounded, in a timely manner, is very under-appreciated.  Smaller ships can and will do this to a limited degree, but a purpose-built ship has capacity that destroyers lack.  If there's a mud slide or fire or earth quake that destroys a town, a nearby carrier is like "manna from heaven".  Even the smallest carriers have cavernous hangar bays that can be packed to the gills with food and water, or a makeshift trauma triage center set up in the hangar bay to treat the wounded.  Purpose-built ships are even better, but spendy, and you don't get to use them very often.

5. To provide a top-notch air crew training program that creates aviators with superb basic airmanship skills, useful for saving stricken airliners
Flying from aircraft carriers forces air crews to become better aviators because maneuvers must be more precise, greater attention to detail is exercised when it comes to the aircraft's "health" is required (there's very little of the usual "we'll try flying this marginally mission capable plane, just for the hours"), weather briefs are considered a critical integral element of every flight brief rather than a check in the block, great effort is spent detailing alternative ingress and egress routes to get yourself out of trouble (from bad weather and enemy action), and an absolute mastery of emergency procedures is necessary, so that the response to a safety-of-flight incident is instant and decisive.  Most fast jet pilots are pretty decisive in the cockpit, but naval aviation takes it to another level.  You cannot be complacent or indecisive or gloss over details while operating jet aircraft from a ship, or people will die.  I don't doubt that there are more than a few Air Force and Army aviators who are every bit as well-trained and detail-oriented, but all of them said they learned something on exchange tours to become carrier qualified.

RobertDyck,

I'm not sure what you had in mind, but a ship the size of a super carrier would require 8 OK-900A reactors to provide 208MW of propulsive power.  The 8 reactor compartments carried by Enterprise weighed about 13,208t.  To that figure you must add the weight of the geared steam turbines.  4,000,000 gallons of F-76 weighs about 12,882t for reference purposes.  Unlike a nuclear reactor, that weight will be situated in the lowest portion of the ship's hull, where it aids in maintaining stability in rough weather.  Most or nearly all of Enterprise's reactor weight was situated below the waterline, so that's good, but still not as good as fuel in the fuel bunkers.  At least some ships of the Nimitz class, interestingly enough, have a slight list due to a weight distribution problems, although I don't think the reactors were the  cause of the list, but I can't recall.

USS Nimitz covered 100,395 statute miles during 321 consecutive days at sea while the COVID pandemic was in full swing.  To the best of my knowledge, that represents the greatest total number of miles covered during a single carrier battle group deployment.  There was every incentive to minimize at-sea replenishment activities to slow or prevent the spread of COVID.

100,395 / 7,704 hours = 13.0315mph / 11.332 knots <- average speed of travel

Q: Why did USS Nimitz travel at that speed?
A: Her escorts don't have nuclear power, so she had to deliberately keep her speed slow enough that her escorts wouldn't require constant fuel replenishment.

At that cruising speed, a SCO2 powered Kitty Hawk class aircraft carrier would burn 2,355,241.2 gallons of fuel, or a little more than half of her 4,000,000 gallon diesel fuel load.  The historical steam boiler powered Kitty Hawk class would burn 7,065,723.6 gallons of fuel, so she would require at least one UNREP event to replenish her fuel oil bunkers, probably two since they don't like it when the ship's fuel load drops below 50%.  That said, if you have SCO2 power and you're going to travel that slowly, then the carrier doesn't need any fuel replenishment for a very long time.

My brain still understands how to count, so it can't concoct a reality-based scenario where a carrier either leaves all her escorts behind to prove that she can sail off at 30 knots ('cause nuclear power, man!), and it also understands that making every ship in the battle group nuclear powered is a total non-starter on cost alone.  If I'm more than doubling the cost of the carrier, then I want to know what it is that I'm actually "saving" by switching to nuclear power.  I have a capability I cannot use for double the cost of the alternative.  Maybe that made perfect sense to Admiral Rickover, but it makes no sense to me, because I'd rather have 2 CV-63s (with drastically more efficient propulsion) for the price of 1 CVN-68.  I can purchase 7 CV-63s for the price of 1 CV-78.  There is no capability that 1 CVN-78 possesses which makes it worth the price of 7 CV-63s.

During operation "prove that a nuclear ship doesn't require at-sea fuel replenishment", aka "Operation Sea Orbit", in 1964, USS Enterprise, USS Long Beach, and USS Bainbridge (all nuclear powered) sailed 30,216 miles during 57 consecutive days at sea, which means their speed was 22.09mph, or slightly less than 19.21 knots.

Could a SCO2 powered Kitty Hawk class sail at 19 knots for 1,368 hours without fuel replenishment?

Basic math says it could, for a lot less money.

What, then, is the actual point of having a singular all-nuclear carrier battlegroup or a battlegroup where only the carrier is nuclear powered?

Sea Orbit was a theatrical stunt concocted by Vice Admiral John S. McCain, Jr, who wanted to "prove" that nuclear powered ships don't require replenishment oilers.  This is facially absurd, though, since all the aircraft were still powered by jet fuel.  No actual warfighting capability is added by such stunts.  While those ships were all quite capable for their era, leaving your sub chasers and radar picket ships behind is a better than average way to get your carrier sunk.

What military problem are you solving for by equipping a singular ship with a nuclear reactor?

Edit:
Apologies, RobertDyck, but I used the fuel burn rate data for the wrong ship in my above calculations.  It was late when I first wrote that and I had a headache.  I realized my error almost as soon as I posted it, but decided to leave it there.  My data comes from a research paper from the Naval Postgraduate School in Monterey, entitled "Predicting Ship Fuel Consumption: Update, by David A. Schrady, Gordon K. Smyth, Robert B. Vassian, July, 1996".  The code for the paper is "ADA313847.pdf".

Kitty Hawk's historical burn rate at 11.1 knots was 2,482gph, so a SCO2 power plant would burn approximately 827.33gph, which means 4,835hrs of plant operation at 13.0315mph.  That implies 63,004 statute miles of range, so 1 UNREP even to replenish the ship's fuel bunkers would be required to travel 100,395 statute miles at 13.0315mph, using a SCO2 power plant.  Even so, I think that accurately illustrates how silly the "range anxiety" problem is.  When Nimitz made her record deployment, she did take on fuel for her air wing many times, though, so the idea that a nuclear powered ship requires no fuel replenishment remains a fantasy.  There is no such thing as operating a super carrier (as a mobile airfield) without underway fuel replenishment.

RobertDyck,

If Canada is serious about operating aircraft carriers while remaining within its limited military budget, then it should operate conventionally powered carriers that don't require spending any precious defense dollars on all the support activities required to operate naval nuclear reactors.  There's no clear military justification for nuclear power on surface warships, unless all the ships in the battle group are nuclear powered, because an aircraft carrier would never leave its escorts behind.  Nuclear power is an extravagance that most nations cannot afford.  Since all the other ships in the battle group and the aircraft themselves are still conventionally powered, adding nuclear reactors to the carrier doesn't economize on very many underway refueling events.

The high fuel burn rates associated with historical conventionally powered American aircraft carriers were due to the poor thermal efficiency of WWII era steam boilers, which was about 16.5% according to empirical data collected for speeds of 20 knots and 30 knots from the Kitty Hawk class, which were the last class of conventionally powered American aircraft carriers.  Modern gas turbines, such as the latest versions of the LM2500, when run at max output / max thermodynamic efficiency, fall between 36% and 39%.  Supercritical CO2 gas turbines would be 50% thermally efficient.

Kitty Hawk class cruising range / operating hours at 20 knots / 23mph, by propulsion plant technology:
Foster-Wheeler or Babcock and Wilcox Marine Boilers: 13,800 statute miles (600 hours)
LM2500s: 30,109 statute miles (1,309 hours)
Supercritical CO2 gas turbines: 41,818 statute miles (1,818 hours)

Kitty Hawk's longest operational deployment covered 62,000 statute miles.  That means you'd need to refuel the ship once per 6 month deployment, or perhaps never if you only deploy your carriers for 3 months.

If Canada operated navalized variants of Textron AirLand's Scorpion, equipped with the latest sensors and weapons, they'd have more real combat power than most other navies.  These fighters would be drastically cheaper to operate than all the heavy fighters operated by other western navies, so several squadrons could be purchased and deployed.  Their simplicity, economy of operation, and range matters a lot more than how fast they are.  The Scorpion is a twin-engine subsonic ISR / attack jet with 2 crew members and an internal weapons bay.  Naval fighters benefit greatly from the ability to loiter at significant distances from their carrier.  Modern heavy fighters cannot loiter for any significant period of time because they require so much power to remain aloft.

Numbers of combat jets matter far more than theoretical capabilities.  In real life you launch with 2 primary weapons to perform your mission, because that's what you can land with.  If you can launch with a pair of 2,000 pound class munitions and 2 to 4 defensive missiles, that's as heavy a loadout as you need.  Anything more than that rapidly becomes impractical nonsense.

Let's say you field 2 air wings with 48 Scorpions per air wing, and deploy with half of the air wing at any given time on 3 month deployments, so you deploy twice per year.  Let's assert that 18 of the 24 jets can fly each day on a single 4 hour mission.

18 jets * 4 flight hours per day * 130 flight ops days per year * $3,000 per flight hour = $28.08M per half air wing per year

Each crew receives approximately 390 hours of operational flying from the carrier per year (similar to the number of hours our squadron's air crews were accumulating during Operation Enduring Freedom), plus maybe 50 to 70 hours of flying back at a naval air station for recurrent training / work-ups.  That makes them highly proficient aviators in at least one mission area, with enough spare flight hours for a secondary specialty, because they're getting a lot more hours than virtually any other western flight crews receive during peace time.  All of this is possible because Canada selected a fighter with modest CPFH, so the money saved on airframe maintenance can instead be devoted to far more training hours with high quality sensors / weapons.

$56.16M per air wing per year, or $113.32M total cost to maintain 2 carrier mobile air wings.  That's the purchase price for 1X F-35C, but instead of spending that amount of money merely to purchase stealthy heavy fighters, you're fielding 2 complete air wings embarked aboard 4 CATOBAR aircraft carriers deployed over non-consecutive 3 month deployment periods per year to increase sailor retention and to reduce the toll exacted on the equipment that would otherwise be associated with 6+ month deployments.  There should also be fewer problems with complacency killing people.  Around the 3 to 4 month mark, the younger American sailors seem to become complacent to the danger they're in on the flight deck.  Maybe Canadian sailors are different, but I doubt it.  This is mostly a "young man" problem.

Since the carriers are conventionally powered, one ship can have a skeleton crew aboard while in-port undergoing repairs / refurbishment while the other carrier is at sea.  That provides 24/7/365 at-sea defense of the Atlantic and Pacific Canadian coastlines, in order to get between any potential aggressor and the Canadian homeland.  If Canada has something equivalent to a Defense Logistics Agency, those are the people who would be refurbishing the carrier in port, so that most of your sailors can fully crew the operational carrier.

One of the key features of conventionally powered carriers is that you truly can "walk away" from them if you need to.  If one of the four carriers requires complex overhaul, that ship doesn't need her crew present to babysit the reactor.  There is no such thing as walking away from a nuclear powered ship.  You're married to her.

If you're smart about how you design the electronics suite and defensive weapons, the possibility exists for anything classified to be entirely removed from the ship and stored separately, such that even fewer crew members need to remain aboard, perhaps limited to a handful of engineering officers overseeing the repair activities.  At that point, it's functionally no different from a civilian ship.  If the officers and a yard crew need to take her out for a shakedown, they can do that with minimal fuss.

Minimal complexity that doesn't sacrifice real combat capability is the name of the game here.  You get 2 limited capability carrier battle groups that have the most important features of an American blue water carrier battle group, at a fraction of what America pays for the pointless techno-gadgets that may have some theoretical advantage in some specific scenario, but aren't doing much for anyone at all other times.

AIM-174 - Fleet air defense against sea-skimming and ballistic missile threats
AIM-120 - General purpose air superiority
AIM-9 - Defensive missiles

JDAM-ER - Precision all-weather stand-off bombing with data-link
Harpoon / SLAM - All-weather stand-off anti-ship or land attack cruise missiles
AARGM-ER - Stand-off anti-radiation missile for SEAD

Bay-mounted ISAR Pod - Organic mini-AWACS capability
Bay-mounted Camera Pod - Organic photo-recon / bomb damage assessment capability

I think that provides a good mix of capabilities that cover most missions an air wing attached to a limited capability carrier battle group could realistically be tasked to perform.  The weapons selected are adequate for their intended use cases.  No specialty weapons such as Hellfire or APKWS or SDB or bunker busters were included because they're inappropriate for a blue water naval force primarily focused on interdicting enemy bombers, tactical fighters, and ships, with the odd land-based target of opportunity that may appear.  You can still clobber the snot out of any tank with a JDAM.  It's cheaper than a Hellfire, can potentially fly much farther, and there won't be much left after it hits.  It will require off-board data link guidance to hit a moving target, but it works.

RobertDyck,

You're too immature to accept that I'm asking you for a more substantive answer than, "Putin is stupid".  If an accusation of treason is the only kind of answer you can provide, then that means you haven't devoted any real thought to why Russia invaded Ukraine.  You're too emotional to be rational.

If Putin's as stupid as you claim, then why is he still in power?

He's such an idiot that he's retained power for almost as long as Stalin.  I'm calling BS on that.

If Putin has an itchy trigger finger, then what's stopped him from launching his ICBMs?

All those dead Ukrainians are evidence that the Russians did get a vote.  All your assertions about what is true and what is right are not going to bring them back.

Send the Canadian Army to arrest Putin, if you actually think that will work.

If asking pertinent questions about your reductive logic is "defending Russia", then I'm not dealing with a rational actor.  Go cool off and come back with a more thoughtful response.

You're making an appeal to an "authority" who cannot be questioned and hasn't published the basis for their findings.  You didn't even name your source.

The Russians are offloading their crude to foreign-flagged ships now.  China and India still accept Russian crude, but from tanker ships not registered to Russian owners.  Crude oil is one of the few substances more addictive than sugar.  Modern civilization doesn't function without it.  I'd be shocked if Russian crude wasn't being imported into the US the entire time President Biden was in office.

Iran has been sanctioned for decades.  Sanctions never stopped them from acquiring weapons or waging war against the Israelis, and their citizens have not overthrown their government.  If they did overthrow their government, do you seriously think "Death to Israel" / "Death to America" would not still be as common as citing verses from the Quran?  You'd have to be really naive to think that would change overnight.

Unless Putin dies, he's not leaving office.

Russia will eventually run out of people and war machines, but that process might take decades and there may not be anything left of Ukraine by the time it actually happens.  Ukraine has not "won" anything thus far, and when last I checked the Russian Army is still in Ukraine.  I think the fastest way for the Russian Army to leave Ukraine is for Putin to command them to leave.  You seem to think that'll be accomplished by upping the stakes in our international pissing contest with Russia, which hasn't convinced the Russians to leave so far.

Russia has a "land military", heavy on tanks and artillery.  America and the rest of Europe have delivered more anti-armor munitions to Ukraine than there are tanks on planet Earth, yet the Russian Army is still in Ukraine and still using tanks and artillery.  I don't know about you, but I think the reason is probably not that western anti-armor munitions can't destroy a Russian tank, but rather that the number of Ukrainians capable of firing those weapons at Russian tanks is dwindling.

Unlike you, I actually cite relevant sources when my arguments are based upon it, because reality matters to me (even when I don't like it):
Defending Europe without the US: first estimates of what is needed

I did not ask you about why Putin thinks or believes what he does.  I asked you if you think his reasoning is or is not shared amongst his fellow Russians.  Pretend for a moment that Putin does not exist.  Poof!  Putin just disappeared, never to be seen or heard from again.  Does that mean whomever seizes power next won't simply continue doing exactly what Putin has been doing?

You're one of our, "If I could get in my magic time machine and kill baby Hitler, then WWII would've never happened."  Hitler was a speaker who the people would listen to.  He was very far from the most effective leader / strongman that the nazis had.  If Hitler never existed, there's a better than average probability that someone willing to listen to his generals would've seized power.  That would've been truly scary, because whomever that person was, he may have achieved what someone with a Corporal's understanding of war never could.

Do you think two or more people in Russia are utterly incapable of having the same strategic objectives, and may very well use the exact same methods to achieve them?

Putin's been in power now for almost 21 years.  He's the devil we know.  As long as he's there, I know what his priorities are, because he very helpfully wrote them down for us.  Whenever he leaves, I can guarantee one thing- we won't know nearly as much about his successor.

Do you ever worry that someone more effective than Putin might take his place?:
The men who could succeed Vladimir Putin

You should.

RobertDyck,

Attempting to admit Ukraine into NATO will ensure that the war with Russia continues.  That was the entire stated reason for starting the war.  The rest of the nonsense thrown out by Putin about rebuilding the Russian empire was merely his personal beliefs, which are not germane to the primary issue Russia has with having NATO countries on their borders.  If Putin was gone tomorrow, the Russians would still be fighting in Ukraine to prevent NATO's eastward expansion, because that's a national priority for them.  You have to separate national geopolitical issues from specific personalities in government.  If all political parties are after the same objectives, then it's no longer about who's in charge, because regardless of who presently holds power, their strategic objectives are congruent.  This is the same as thinking you're going to get a night-and-day different Soviet Union under Kruschev vs Stalin.  It's the same Soviet Union with a different person in charge.  There will be some reshuffling of national priorities, but not on major contentious issues.

All that oil and gas that was headed to Europe is now headed to China.  If you think the Russian economy will collapse if Russian oligarch money in Brussels is not released, then you should be able to tell us why the Russian economy hasn't collapsed already.  Peter Zeihan told us that the Russian oil and gas industry would collapse after the winter froze all of it in the pipelines leading to Europe.  We blew up the Nordstream pipelines, but output of Russian oil and gas basically hasn't changed much over the past several years, because it's being redirected to China and India.  Peter clearly didn't account for that possibility.  Since Europe is an unreliable customer compared to China, Russia is not going to redirect the output back to Europe after the fighting stops, which means their source of income is stable, so they can continue producing weapons until they run out of raw materials.  I wouldn't count on Russia running out of Iron, wood, and chemicals to make weapons.

Maybe it's time for a reality check on how "integrated" Russia actually is into the global economy.  I don't think there is any integration to speak of.  You can only take Russia's internationally-held money one time, and then it's no longer a bargaining chip.  Now they view the West / NATO as thieves, in addition to being duplicitous on the matter of eastward NATO expansion.  You're removing the incentive they have to negotiate, which means you're either going to militarily defeat them, or they overrun over Ukraine in due time.

So, then, short of using nuclear weapons, how does the EU intend to defeat the Russian Army?

Where are all those divisions of men and equipment to be supplied by the EU, and why are they not already amassed on the border of Ukraine?

They either don't exist, the Europeans are unwilling to use them, or they're not able to be used for the aforementioned logistical reasons.

How many operational tanks can France, Germany, and the UK send into Ukraine for combined arms maneuver warfare?

How many artillery pieces are available for support?

How many combat coded jets are available to support the ground maneuver element, and what vulnerability do they have to Russian SAM systems unless the very first missions are SEAD, rather than support?

I think you'll be shocked by how few are ready to be used.

RobertDyck,

America didn't "get bored" playing global policeman, America "got poor".  There's a difference.  It's amazing how someone with more than enough information to figure out what's going on can contort the situation to mean what he wants it to mean, rather than what it actually means.

Since the EU's military budget will now match America's annual military budget, all the leaders in Europe disagree with your assertion.  You are not remotely qualified to determine what is or isn't reasonable.  Your beliefs reflect having lived your entire life sheltered from the very ugly reality of life elsewhere in the world, where China or Russia or North Korea or Iran is your nextdoor neighbor.

If Europe has such a strong military, why does America need to maintain any military bases in Europe at all?

The US maintains 3 facilities in Australia that host seasonal military exercise participants:
Naval Communication Station Harold E. Holt
Joint Defence Facility Pine Gap
Robertson Barracks

Could we close those facilities?

Sure.  How would we conduct military exercises with the Australians without them, though?

Marines have to be housed somewhere if they're going to be involved in an exercise spanning six months.

94% of all US personnel stationed overseas are deployed to only 10 countries:
Japan
Germany
South Korea
Italy
United Kingdom
Bahrain
Spain
Turkey
Norway
Belgium

The total head count for forward deployed forces varies between 150,000 and 200,000.

We could bring all those people home, but to what end?  Merely to send them back out for their annual exercises with partner nations?  If they're going to be there for 6 months anyway, what sense does that make?

Post WWII wasn't peaceful anywhere in the developing world.  Whether you blame local dictators, economic circumstances, or America for that undeniable fact, the simple fact remains that there was nothing but war following WWII if you lived in the developing world.  The wars were no longer on the doorsteps of major colonial powers because that is what the US sought to end with Bretton-Woods, but war as a way of life never went away.  Ask someone who lives in Africa or Southeast Asia how "peaceful" the latter half of the 20th century was.

We're trying something new here.  We're going to try to get along with Russia, rather than constantly antagonizing them.  For all practical purposes, after China becomes comfortable invading their neighbors, we're going to need Russia and India to help contain them.  You may think this is a matter of secondary importance to the war in Ukraine, but the entire world will think differently if their entire supply of advanced microchips is cut off in 2027.

Tariffs have been applied to American products imported into Canada, China, and Mexico for many decades longer than President Trump has been in office.  Please explain why tariffs applied to American products imported into Canada, China, and Mexico are a good thing, and somehow not a tax levied against Canadian, Chinese, and Mexican consumers.

Is there any "greater magic" by which tariffs are a good thing when imposed upon American-made products imported into other countries, but bad when America imposes tariffs on products from countries that have historically applied a multitude of tariffs to American-made products?

That last part about tariffs on China "making sense", really doesn't make any sense if we're being completely logically consistent, but some members on this forum are not being logically consistent.  They want preferential rules applied to their country, but take no issue with applying tariffs to other nation they're competing against.  Is that type of inconsistency is a "special form" of consistency?

Maybe, just maybe, tariffs are being used by President Trump to protect American workers from foreign governments that are allowed to sell their products into America without tariffs, while their governments turn right back around and imposes significant tariffs on American made products, knowing full well that the end result will be the transfer of wealth of Americans to foreign countries.  That was the reasoning used by foreign countries for their application of tariffs to American-made products.  What's good for the goose is also good for the gander, or it's not good at all and needs to stop.

There is no actual shortage of those materials here in America, only the willpower to go after them.  Democrat Presidents have repeatedly denied offshore drilling and mining permits to American businesses to open new mines here in America.  It's time for that practice to end.  We have enough Lithium in two deposits to bury all other global producers of Lithium.  Democrats want EV mandates, so let them live next to some Lithium mines.  They're going to become like President Biden from chronic exposure, but at least they won't have to remember how to drive their self-driving car.  If those materials are all-important, then they should be extracted here in America by American labor, with American environmental regulations applied to the extraction processes.  That way, no other nation can claim they're being exploited by America.

Our Democrats just imported at least ten million people with which to create a new low-skill manufacturing economy here in America, and Mexico helped them do it.  In the very near future, most manufacturing jobs will be done by robots, which require no sleep, take no lunch breaks, are paid no wages, do not go on strike after their demands for increased wages cannot be met without bankrupting the company, and only require electricity to continue producing.  $25K for a robot that will never miss a day of work is peanuts compared to paying for a human worker.  Necessity is the mother of all invention.

What I just described is how commerce is going to function everywhere in the world, inside of the next 20 years or so.  Every nation produces their own materials, goods, and services, locally, and only trades with foreign countries when they absolutely cannot create a locally-sourced like-kind substitute.  Fewer things get produced in aggregate because it's not necessary to produce as many things when they're made to a higher quality standard and aren't deliberately designed to break.  That tends to drive down over-consumption, which Democrats constantly tell me is a bad thing.  You'd think they'd be happier about what President Trump is doing to achieve their stated climate policy objectives, but I guess they only meant consumption is bad when someone else is allowed to do what they do, even though that still doesn't make any sense.  They talk a lot, spend a lot of other peoples' money, and accomplish nothing.  It's part of their charm.

Europeans constantly criticize Americans for consuming too much.  Now we're going to consume a lot less foreign-made products, hopefully none in the very near future.  Does all the hysteria over President Trump reducing over-consumption by Americans mean we that Europeans actually want us to continue acting like Americans?  I want some logical consistency, please and thank you.

If all the container ships filled with goods made in Asia or Europe or Canada and Mexico stopped arriving at American ports tomorrow, it would force Americans to prioritize what our true "needs" are, and then work towards "wants" after we reestablish local production.  I can only dream of that day right now, but if Americans want a return to prosperity, that is what we must do.

I haven't purchased an article of clothing since before COVID started, and some of my clothes are older than my children.  If I ever do need a new shirt or pair of pants, then I'll see what's available at the local thrift store.  If that's not an option, then I'll buy whatever was made here, or learn to make do without.  I spent the first half of my working life living out of a bag.  Regardless of what I may want, I lost nothing of value by doing that.  I may not be "fashionable" by European or coastie liberal standards, but I have more money in my pocket by refraining from purchasing anything I don't truly need.

People from my parents' generation spent their entire lives bankrupting everyone with their excess, but now it's time to pay for their excess, and pay we must, because we want a better future for our children.  I'm not upset at them because they were never raised to know any better.  At the same time, they gave us lots of great technological advancements, and were very industrious workers, so I chalk up the over-expenditure of public money to a misadventure borne of lack of reasoning about what it would lead to.

We're going back to a multi-polar world where America will only be one major player amongst many- Europe Union, Russia, China, India, Japan, Brazil, Saudi Arabia, Turkey, etc.  That way the rest of you can blame yourselves or each other, rather than America, whenever something doesn't go your way.  If you choose to start another world war due to the lack of maturity of your leaders, that's on you.  We're bowing out of the superpower game because we're not wanted or needed in our current role.  Now there are real consequences to an ill-advised war, so think carefully about who you give power to.

tahanson43206,

You need about 40MWth of input power per kiloNewton of thrust generated at the same temperature and therefore Isp as a solid core nuclear thermal reactor, so 2GWth translates into about 50kN of thrust.  This assumes the use of Hydrogen as the propellant.  You can use higher mass propellants to generate more thrust, such as Methane or Ammonia or CO2, but pure Hydrogen will always provide the highest Isp, which is what we're after in this instance.

Calliban,

My surmise is that this plasma field has to be significantly denser than Earth's Van Allen belts and upper atmosphere due to scaling and the power input to maintain the field, because it has to be dense enough to produce collisions with incoming relativistic ions for it to be effective.

After a plasma sheath has been inflated, how does one communicate with the people or robotic equipment inside this proto-planet space station / mining operation?

Are there optical devices capable of penetrating through the plasma, perhaps X-ray laser communications?

If not, or if the signal distortion from plasma interaction is too great over vast distances, what about a laser comm relay satellite in orbit around it?

When we want to receive visiting spacecraft for transfer of crew / cargo / mined resources from the asteroid, will we have any electrostatic discharge or heating issues that might mess with its onboard systems?